Merge remote-tracking branch 'upstream/master' into aucmd_textputpostaucmd_textputpost

15 files changed, 3196 insertions, 465 deletions

diff --git a/test/functional/api/autocmd_spec.lua b/test/functional/api/autocmd_spec.lua
index 22a1311ee9..fd46a1dcfa 100644
--- a/test/functional/api/autocmd_spec.lua
+++ b/test/functional/api/autocmd_spec.lua
@@ -14,14 +14,40 @@ before_each(clear)
 
 describe('autocmd api', function()
   describe('nvim_create_autocmd', function()
-    it('"command" and "callback" are mutually exclusive', function()
-      local rv = pcall_err(meths.create_autocmd, "BufReadPost", {
-        pattern = "*.py,*.pyi",
+    it('validation', function()
+      eq("Cannot use both 'callback' and 'command'", pcall_err(meths.create_autocmd, 'BufReadPost', {
+        pattern = '*.py,*.pyi',
         command = "echo 'Should Have Errored",
-        callback = "NotAllowed",
-      })
-
-      eq("specify either 'callback' or 'command', not both", rv)
+        callback = 'NotAllowed',
+      }))
+      eq("Cannot use both 'pattern' and 'buffer' for the same autocmd", pcall_err(meths.create_autocmd, 'FileType', {
+        command = 'let g:called = g:called + 1',
+        buffer = 0,
+        pattern = '*.py',
+      }))
+      eq("Required: 'event'", pcall_err(meths.create_autocmd, {}, {
+        command = 'ls',
+      }))
+      eq("Required: 'command' or 'callback'", pcall_err(meths.create_autocmd, 'FileType', {
+      }))
+      eq("Invalid 'desc': expected String, got Integer", pcall_err(meths.create_autocmd, 'FileType', {
+        command = 'ls',
+        desc = 42,
+      }))
+      eq("Invalid 'callback': expected Lua function or Vim function name, got Integer", pcall_err(meths.create_autocmd, 'FileType', {
+        callback = 0,
+      }))
+      eq("Invalid 'event' item: expected String, got Array", pcall_err(meths.create_autocmd,
+        {'FileType', {}}, {}))
+      eq("Invalid 'group': 0", pcall_err(meths.create_autocmd, 'FileType', {
+        group = 0,
+        command = 'ls',
+      }))
+
+      eq("Invalid 'event': 'foo'", pcall_err(meths.create_autocmd, 'foo', { command = '' }))
+      eq("Invalid 'event': 'VimEnter '", pcall_err(meths.create_autocmd, 'VimEnter ', { command = '' }))
+      eq("Invalid 'event': 'VimEnter foo'", pcall_err(meths.create_autocmd, 'VimEnter foo', { command = '' }))
+      eq("Invalid 'event': 'BufAdd,BufDelete'", pcall_err(meths.create_autocmd, 'BufAdd,BufDelete', { command = '' }))
     end)
 
     it('doesnt leak when you use ++once', function()
@@ -59,18 +85,8 @@ describe('autocmd api', function()
       eq(1, meths.get_var('called'))
     end)
 
-    it('does not allow passing buffer and patterns', function()
-      local rv = pcall_err(meths.create_autocmd, "Filetype", {
-        command = "let g:called = g:called + 1",
-        buffer = 0,
-        pattern = "*.py",
-      })
-
-      eq("cannot pass both: 'pattern' and 'buffer' for the same autocmd", rv)
-    end)
-
     it('does not allow passing invalid buffers', function()
-      local ok, msg = pcall(meths.create_autocmd, "Filetype", {
+      local ok, msg = pcall(meths.create_autocmd, 'FileType', {
         command = "let g:called = g:called + 1",
         buffer = -1,
       })
@@ -209,7 +225,7 @@ describe('autocmd api', function()
 
       local aus = meths.get_autocmds({ event = 'User', pattern = 'Test' })
       local first = aus[1]
-      eq(first.id, 1)
+      eq(true, first.id > 0)
 
       meths.set_var("some_condition", true)
       meths.exec_autocmds("User", {pattern = "Test"})
@@ -217,23 +233,28 @@ describe('autocmd api', function()
     end)
 
     it('receives an args table', function()
-      local res = exec_lua [[
-        local group_id = vim.api.nvim_create_augroup("TestGroup", {})
-        local autocmd_id = vim.api.nvim_create_autocmd("User", {
+      local group_id = meths.create_augroup("TestGroup", {})
+      -- Having an existing autocmd calling expand("<afile>") shouldn't change args #18964
+      meths.create_autocmd('User', {
+        group = 'TestGroup',
+        pattern = 'Te*',
+        command = 'call expand("<afile>")',
+      })
+
+      local autocmd_id = exec_lua [[
+        return vim.api.nvim_create_autocmd("User", {
           group = "TestGroup",
           pattern = "Te*",
           callback = function(args)
             vim.g.autocmd_args = args
           end,
         })
-
-        return {group_id, autocmd_id}
       ]]
 
       meths.exec_autocmds("User", {pattern = "Test pattern"})
       eq({
-        id = res[2],
-        group = res[1],
+        id = autocmd_id,
+        group = group_id,
         event = "User",
         match = "Test pattern",
         file = "Test pattern",
@@ -241,27 +262,24 @@ describe('autocmd api', function()
       }, meths.get_var("autocmd_args"))
 
       -- Test without a group
-      res = exec_lua [[
-        local autocmd_id = vim.api.nvim_create_autocmd("User", {
+      autocmd_id = exec_lua [[
+        return vim.api.nvim_create_autocmd("User", {
           pattern = "*",
           callback = function(args)
             vim.g.autocmd_args = args
           end,
         })
-
-        return {autocmd_id}
       ]]
 
       meths.exec_autocmds("User", {pattern = "some_pat"})
       eq({
-        id = res[1],
+        id = autocmd_id,
         group = nil,
         event = "User",
         match = "some_pat",
         file = "some_pat",
         buf = 1,
       }, meths.get_var("autocmd_args"))
-
     end)
 
     it('can receive arbitrary data', function()
@@ -294,8 +312,32 @@ describe('autocmd api', function()
   end)
 
   describe('nvim_get_autocmds', function()
+    it('validation', function()
+      eq("Invalid 'group': 9997999", pcall_err(meths.get_autocmds, {
+        group = 9997999,
+      }))
+      eq("Invalid 'group': 'bogus'", pcall_err(meths.get_autocmds, {
+        group = 'bogus',
+      }))
+      eq("Invalid 'group': 0", pcall_err(meths.get_autocmds, {
+        group = 0,
+      }))
+      eq("Invalid 'group': expected String or Integer, got Array", pcall_err(meths.get_autocmds, {
+        group = {},
+      }))
+      eq("Invalid 'buffer': expected Integer or Array, got Boolean", pcall_err(meths.get_autocmds, {
+        buffer = true,
+      }))
+      eq("Invalid 'event': expected String or Array", pcall_err(meths.get_autocmds, {
+        event = true,
+      }))
+      eq("Invalid 'pattern': expected String or Array, got Boolean", pcall_err(meths.get_autocmds, {
+        pattern = true,
+      }))
+    end)
+
     describe('events', function()
-      it('should return one autocmd when there is only one for an event', function()
+      it('returns one autocmd when there is only one for an event', function()
         command [[au! InsertEnter]]
         command [[au InsertEnter * :echo "1"]]
 
@@ -303,7 +345,7 @@ describe('autocmd api', function()
         eq(1, #aus)
       end)
 
-      it('should return two autocmds when there are two for an event', function()
+      it('returns two autocmds when there are two for an event', function()
         command [[au! InsertEnter]]
         command [[au InsertEnter * :echo "1"]]
         command [[au InsertEnter * :echo "2"]]
@@ -312,7 +354,7 @@ describe('autocmd api', function()
         eq(2, #aus)
       end)
 
-      it('should return the same thing if you use string or list', function()
+      it('returns the same thing if you use string or list', function()
         command [[au! InsertEnter]]
         command [[au InsertEnter * :echo "1"]]
         command [[au InsertEnter * :echo "2"]]
@@ -322,7 +364,7 @@ describe('autocmd api', function()
         eq(string_aus, array_aus)
       end)
 
-      it('should return two autocmds when there are two for an event', function()
+      it('returns two autocmds when there are two for an event', function()
         command [[au! InsertEnter]]
         command [[au! InsertLeave]]
         command [[au InsertEnter * :echo "1"]]
@@ -332,7 +374,7 @@ describe('autocmd api', function()
         eq(2, #aus)
       end)
 
-      it('should return different IDs for different autocmds', function()
+      it('returns different IDs for different autocmds', function()
         command [[au! InsertEnter]]
         command [[au! InsertLeave]]
         command [[au InsertEnter * :echo "1"]]
@@ -356,7 +398,7 @@ describe('autocmd api', function()
         eq(first, new_aus[1])
       end)
 
-      it('should return event name', function()
+      it('returns event name', function()
         command [[au! InsertEnter]]
         command [[au InsertEnter * :echo "1"]]
 
@@ -364,7 +406,7 @@ describe('autocmd api', function()
         eq({ { buflocal = false, command = ':echo "1"', event = "InsertEnter", once = false, pattern = "*" } }, aus)
       end)
 
-      it('should work with buffer numbers', function()
+      it('works with buffer numbers', function()
         command [[new]]
         command [[au! InsertEnter]]
         command [[au InsertEnter <buffer=1> :echo "1"]]
@@ -407,8 +449,8 @@ describe('autocmd api', function()
           pattern = "<buffer=2>",
         }}, aus)
 
-        eq("Invalid value for 'buffer': must be an integer or array of integers", pcall_err(meths.get_autocmds, { event = "InsertEnter", buffer = "foo" }))
-        eq("Invalid value for 'buffer': must be an integer", pcall_err(meths.get_autocmds, { event = "InsertEnter", buffer = { "foo", 42 } }))
+        eq("Invalid 'buffer': expected Integer or Array, got String", pcall_err(meths.get_autocmds, { event = "InsertEnter", buffer = "foo" }))
+        eq("Invalid 'buffer': expected Integer, got String", pcall_err(meths.get_autocmds, { event = "InsertEnter", buffer = { "foo", 42 } }))
         eq("Invalid buffer id: 42", pcall_err(meths.get_autocmds, { event = "InsertEnter", buffer = { 42 } }))
 
         local bufs = {}
@@ -416,10 +458,10 @@ describe('autocmd api', function()
           table.insert(bufs, meths.create_buf(true, false))
         end
 
-        eq("Too many buffers. Please limit yourself to 256 or fewer", pcall_err(meths.get_autocmds, { event = "InsertEnter", buffer = bufs }))
+        eq("Too many buffers (maximum of 256)", pcall_err(meths.get_autocmds, { event = "InsertEnter", buffer = bufs }))
       end)
 
-      it('should return autocmds when group is specified by id', function()
+      it('returns autocmds when group is specified by id', function()
         local auid = meths.create_augroup("nvim_test_augroup", { clear = true })
         meths.create_autocmd("FileType", { group = auid, command = 'echo "1"' })
         meths.create_autocmd("FileType", { group = auid, command = 'echo "2"' })
@@ -431,7 +473,7 @@ describe('autocmd api', function()
         eq(0, #aus2)
       end)
 
-      it('should return autocmds when group is specified by name', function()
+      it('returns autocmds when group is specified by name', function()
         local auname = "nvim_test_augroup"
         meths.create_augroup(auname, { clear = true })
         meths.create_autocmd("FileType", { group = auname, command = 'echo "1"' })
@@ -531,7 +573,7 @@ describe('autocmd api', function()
         command [[augroup END]]
       end)
 
-      it('should return all groups if no group is specified', function()
+      it('returns all groups if no group is specified', function()
         local aus = meths.get_autocmds { event = "InsertEnter" }
         if #aus ~= 4 then
           eq({}, aus)
@@ -540,7 +582,7 @@ describe('autocmd api', function()
         eq(4, #aus)
       end)
 
-      it('should return only the group specified', function()
+      it('returns only the group specified', function()
         local aus = meths.get_autocmds {
           event = "InsertEnter",
           group = "GroupOne",
@@ -551,7 +593,7 @@ describe('autocmd api', function()
         eq("GroupOne", aus[1].group_name)
       end)
 
-      it('should return only the group specified, multiple values', function()
+      it('returns only the group specified, multiple values', function()
         local aus = meths.get_autocmds {
           event = "InsertEnter",
           group = "GroupTwo",
@@ -578,7 +620,7 @@ describe('autocmd api', function()
         ]], {}))
 
         eq(false, success)
-        matches('invalid augroup: NotDefined', code)
+        matches("Invalid 'group': 'NotDefined'", code)
       end)
 
       it('raises error for undefined augroup id', function()
@@ -596,7 +638,7 @@ describe('autocmd api', function()
         ]], {}))
 
         eq(false, success)
-        matches('invalid augroup: 1', code)
+        matches("Invalid 'group': 1", code)
       end)
 
       it('raises error for invalid group type', function()
@@ -611,7 +653,7 @@ describe('autocmd api', function()
         ]], {}))
 
         eq(false, success)
-        matches("'group' must be a string or an integer", code)
+        matches("Invalid 'group': expected String or Integer, got Boolean", code)
       end)
 
       it('raises error for invalid pattern array', function()
@@ -625,7 +667,7 @@ describe('autocmd api', function()
         ]], {}))
 
         eq(false, success)
-        matches("All entries in 'pattern' must be strings", code)
+        matches("Invalid 'pattern' item: expected String, got Array", code)
       end)
     end)
 
@@ -640,7 +682,7 @@ describe('autocmd api', function()
         command [[au InsertEnter <buffer> :echo "Buffer"]]
       end)
 
-      it('should should return for literal match', function()
+      it('returns for literal match', function()
         local aus = meths.get_autocmds {
           event = "InsertEnter",
           pattern = "*"
@@ -650,7 +692,7 @@ describe('autocmd api', function()
         eq([[:echo "No Group"]], aus[1].command)
       end)
 
-      it('should return for multiple matches', function()
+      it('returns for multiple matches', function()
         -- vim.api.nvim_get_autocmds
         local aus = meths.get_autocmds {
           event = "InsertEnter",
@@ -687,6 +729,26 @@ describe('autocmd api', function()
   end)
 
   describe('nvim_exec_autocmds', function()
+    it('validation', function()
+      eq("Invalid 'group': 9997999", pcall_err(meths.exec_autocmds, 'FileType', {
+        group = 9997999,
+      }))
+      eq("Invalid 'group': 'bogus'", pcall_err(meths.exec_autocmds, 'FileType', {
+        group = 'bogus',
+      }))
+      eq("Invalid 'group': expected String or Integer, got Array", pcall_err(meths.exec_autocmds, 'FileType', {
+        group = {},
+      }))
+      eq("Invalid 'group': 0", pcall_err(meths.exec_autocmds, 'FileType', {
+        group = 0,
+      }))
+      eq("Invalid 'buffer': expected Buffer, got Array", pcall_err(meths.exec_autocmds, 'FileType', {
+        buffer = {},
+      }))
+      eq("Invalid 'event' item: expected String, got Array", pcall_err(meths.exec_autocmds,
+        {'FileType', {}}, {}))
+    end)
+
     it("can trigger builtin autocmds", function()
       meths.set_var("autocmd_executed", false)
 
@@ -1004,6 +1066,12 @@ describe('autocmd api', function()
 
       eq(false, exec_lua[[return pcall(vim.api.nvim_del_augroup_by_id, -12342)]])
       eq('Vim:E367: No such group: "--Deleted--"', pcall_err(meths.del_augroup_by_id, -12312))
+
+      eq(false, exec_lua[[return pcall(vim.api.nvim_del_augroup_by_id, 0)]])
+      eq('Vim:E367: No such group: "[NULL]"', pcall_err(meths.del_augroup_by_id, 0))
+
+      eq(false, exec_lua[[return pcall(vim.api.nvim_del_augroup_by_id, 12342)]])
+      eq('Vim:E367: No such group: "[NULL]"', pcall_err(meths.del_augroup_by_id, 12312))
     end)
 
     it('groups work with once', function()
@@ -1036,7 +1104,7 @@ describe('autocmd api', function()
       local augroup = "WillBeDeleted"
 
       meths.create_augroup(augroup, { clear = true })
-      meths.create_autocmd({"Filetype"}, {
+      meths.create_autocmd({"FileType"}, {
         pattern = "*",
         command = "echo 'does not matter'",
       })
@@ -1055,7 +1123,7 @@ describe('autocmd api', function()
       meths.set_var("value_set", false)
 
       meths.create_augroup(augroup, { clear = true })
-      meths.create_autocmd("Filetype", {
+      meths.create_autocmd("FileType", {
         pattern = "<buffer>",
         command = "let g:value_set = v:true",
       })
@@ -1171,6 +1239,17 @@ describe('autocmd api', function()
   end)
 
   describe('nvim_clear_autocmds', function()
+    it('validation', function()
+      eq("Cannot use both 'pattern' and 'buffer'", pcall_err(meths.clear_autocmds, {
+        pattern = '*',
+        buffer = 42,
+      }))
+      eq("Invalid 'event' item: expected String, got Array", pcall_err(meths.clear_autocmds, {
+        event = {'FileType', {}}
+      }))
+      eq("Invalid 'group': 0", pcall_err(meths.clear_autocmds, {group = 0}))
+    end)
+
     it('should clear based on event + pattern', function()
       command('autocmd InsertEnter *.py  :echo "Python can be cool sometimes"')
       command('autocmd InsertEnter *.txt :echo "Text Files Are Cool"')
@@ -1254,7 +1333,7 @@ describe('autocmd api', function()
       local without_group = meths.get_autocmds(search)
       eq(2, #without_group)
 
-      -- Doest clear with passing group.
+      -- Doesn't clear with passing group.
       meths.clear_autocmds { buffer = 0, group = search.group }
       local with_group = meths.get_autocmds(search)
       eq(1, #with_group)
diff --git a/test/functional/api/buffer_spec.lua b/test/functional/api/buffer_spec.lua
index 6b13729994..6ed9aa574a 100644
--- a/test/functional/api/buffer_spec.lua
+++ b/test/functional/api/buffer_spec.lua
@@ -16,6 +16,7 @@ local command = helpers.command
 local bufmeths = helpers.bufmeths
 local feed = helpers.feed
 local pcall_err = helpers.pcall_err
+local assert_alive = helpers.assert_alive
 
 describe('api/buf', function()
   before_each(clear)
@@ -41,6 +42,14 @@ describe('api/buf', function()
       eq(1, curbuf_depr('line_count'))
     end)
 
+    it("doesn't crash just after set undolevels=1 #24894", function()
+      local buf = meths.create_buf(false, true)
+      meths.buf_set_option(buf, 'undolevels', -1)
+      meths.buf_set_lines(buf, 0, 1, false, { })
+
+      assert_alive()
+    end)
+
     it('cursor position is maintained after lines are inserted #9961', function()
       -- replace the buffer contents with these three lines.
       request('nvim_buf_set_lines', 0, 0, -1, 1, {"line1", "line2", "line3", "line4"})
@@ -76,6 +85,38 @@ describe('api/buf', function()
       eq({4, 2}, curwin('get_cursor'))
     end)
 
+    it('cursor position is maintained in non-current window', function()
+      meths.buf_set_lines(0, 0, -1, 1, {"line1", "line2", "line3", "line4"})
+      meths.win_set_cursor(0, {3, 2})
+      local win = meths.get_current_win()
+      local buf = meths.get_current_buf()
+
+      command('new')
+
+      meths.buf_set_lines(buf, 1, 2, 1, {"line5", "line6"})
+      eq({"line1", "line5", "line6", "line3", "line4"}, meths.buf_get_lines(buf, 0, -1, true))
+      eq({4, 2}, meths.win_get_cursor(win))
+    end)
+
+    it('cursor position is maintained in TWO non-current windows', function()
+      meths.buf_set_lines(0, 0, -1, 1, {"line1", "line2", "line3", "line4"})
+      meths.win_set_cursor(0, {3, 2})
+      local win = meths.get_current_win()
+      local buf = meths.get_current_buf()
+
+      command('split')
+      meths.win_set_cursor(0, {4, 2})
+      local win2 = meths.get_current_win()
+
+      -- set current window to third one with another buffer
+      command("new")
+
+      meths.buf_set_lines(buf, 1, 2, 1, {"line5", "line6"})
+      eq({"line1", "line5", "line6", "line3", "line4"}, meths.buf_get_lines(buf, 0, -1, true))
+      eq({4, 2}, meths.win_get_cursor(win))
+      eq({5, 2}, meths.win_get_cursor(win2))
+    end)
+
     it('line_count has defined behaviour for unloaded buffers', function()
       -- we'll need to know our bufnr for when it gets unloaded
       local bufnr = curbuf('get_number')
@@ -105,6 +146,285 @@ describe('api/buf', function()
       -- it's impossible to get out-of-bounds errors for an unloaded buffer
       eq({}, buffer('get_lines', bufnr, 8888, 9999, 1))
     end)
+
+    describe('handles topline', function()
+      local screen
+      before_each(function()
+        screen = Screen.new(20, 12)
+        screen:set_default_attr_ids {
+          [1] = {bold = true, foreground = Screen.colors.Blue1};
+          [2] = {reverse = true, bold = true};
+          [3] = {reverse = true};
+        }
+        screen:attach()
+        meths.buf_set_lines(0, 0, -1, 1, {"aaa", "bbb", "ccc", "ddd", "www", "xxx", "yyy", "zzz"})
+        meths.set_option_value('modified', false, {})
+      end)
+
+      it('of current window', function()
+        local win = meths.get_current_win()
+        local buf = meths.get_current_buf()
+
+        command('new | wincmd w')
+        meths.win_set_cursor(win, {8,0})
+
+        screen:expect{grid=[[
+                              |
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {3:[No Name]           }|
+          www                 |
+          xxx                 |
+          yyy                 |
+          ^zzz                 |
+          {2:[No Name]           }|
+                              |
+        ]]}
+
+        meths.buf_set_lines(buf, 0, 2, true, {"aaabbb"})
+        screen:expect{grid=[[
+                              |
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {3:[No Name]           }|
+          www                 |
+          xxx                 |
+          yyy                 |
+          ^zzz                 |
+          {2:[No Name] [+]       }|
+                              |
+        ]]}
+
+        -- replacing topline keeps it the topline
+        meths.buf_set_lines(buf, 3, 4, true, {"wwweeee"})
+        screen:expect{grid=[[
+                              |
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {3:[No Name]           }|
+          wwweeee             |
+          xxx                 |
+          yyy                 |
+          ^zzz                 |
+          {2:[No Name] [+]       }|
+                              |
+        ]]}
+
+        -- inserting just before topline does not scroll up if cursor would be moved
+        meths.buf_set_lines(buf, 3, 3, true, {"mmm"})
+        screen:expect{grid=[[
+                              |
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {3:[No Name]           }|
+          wwweeee             |
+          xxx                 |
+          yyy                 |
+          ^zzz                 |
+          {2:[No Name] [+]       }|
+                              |
+        ]], unchanged=true}
+
+        meths.win_set_cursor(0, {7, 0})
+        screen:expect{grid=[[
+                              |
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {3:[No Name]           }|
+          wwweeee             |
+          xxx                 |
+          ^yyy                 |
+          zzz                 |
+          {2:[No Name] [+]       }|
+                              |
+        ]]}
+
+        meths.buf_set_lines(buf, 4, 4, true, {"mmmeeeee"})
+        screen:expect{grid=[[
+                              |
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {3:[No Name]           }|
+          mmmeeeee            |
+          wwweeee             |
+          xxx                 |
+          ^yyy                 |
+          {2:[No Name] [+]       }|
+                              |
+        ]]}
+      end)
+
+      it('of non-current window', function()
+        local win = meths.get_current_win()
+        local buf = meths.get_current_buf()
+
+        command('new')
+        meths.win_set_cursor(win, {8,0})
+
+        screen:expect{grid=[[
+          ^                    |
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {2:[No Name]           }|
+          www                 |
+          xxx                 |
+          yyy                 |
+          zzz                 |
+          {3:[No Name]           }|
+                              |
+        ]]}
+
+        meths.buf_set_lines(buf, 0, 2, true, {"aaabbb"})
+        screen:expect{grid=[[
+          ^                    |
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {2:[No Name]           }|
+          www                 |
+          xxx                 |
+          yyy                 |
+          zzz                 |
+          {3:[No Name] [+]       }|
+                              |
+        ]]}
+
+        -- replacing topline keeps it the topline
+        meths.buf_set_lines(buf, 3, 4, true, {"wwweeee"})
+        screen:expect{grid=[[
+          ^                    |
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {2:[No Name]           }|
+          wwweeee             |
+          xxx                 |
+          yyy                 |
+          zzz                 |
+          {3:[No Name] [+]       }|
+                              |
+        ]]}
+
+        -- inserting just before topline scrolls up
+        meths.buf_set_lines(buf, 3, 3, true, {"mmm"})
+        screen:expect{grid=[[
+          ^                    |
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {2:[No Name]           }|
+          mmm                 |
+          wwweeee             |
+          xxx                 |
+          yyy                 |
+          {3:[No Name] [+]       }|
+                              |
+        ]]}
+      end)
+
+      it('of split windows with same buffer', function()
+        local win = meths.get_current_win()
+        local buf = meths.get_current_buf()
+
+        command('split')
+        meths.win_set_cursor(win, {8,0})
+        meths.win_set_cursor(0, {1,0})
+
+        screen:expect{grid=[[
+          ^aaa                 |
+          bbb                 |
+          ccc                 |
+          ddd                 |
+          www                 |
+          {2:[No Name]           }|
+          www                 |
+          xxx                 |
+          yyy                 |
+          zzz                 |
+          {3:[No Name]           }|
+                              |
+        ]]}
+        meths.buf_set_lines(buf, 0, 2, true, {"aaabbb"})
+
+        screen:expect{grid=[[
+          ^aaabbb              |
+          ccc                 |
+          ddd                 |
+          www                 |
+          xxx                 |
+          {2:[No Name] [+]       }|
+          www                 |
+          xxx                 |
+          yyy                 |
+          zzz                 |
+          {3:[No Name] [+]       }|
+                              |
+        ]]}
+
+        -- replacing topline keeps it the topline
+        meths.buf_set_lines(buf, 3, 4, true, {"wwweeee"})
+        screen:expect{grid=[[
+          ^aaabbb              |
+          ccc                 |
+          ddd                 |
+          wwweeee             |
+          xxx                 |
+          {2:[No Name] [+]       }|
+          wwweeee             |
+          xxx                 |
+          yyy                 |
+          zzz                 |
+          {3:[No Name] [+]       }|
+                              |
+        ]]}
+
+        -- inserting just before topline scrolls up
+        meths.buf_set_lines(buf, 3, 3, true, {"mmm"})
+        screen:expect{grid=[[
+          ^aaabbb              |
+          ccc                 |
+          ddd                 |
+          mmm                 |
+          wwweeee             |
+          {2:[No Name] [+]       }|
+          mmm                 |
+          wwweeee             |
+          xxx                 |
+          yyy                 |
+          {3:[No Name] [+]       }|
+                              |
+        ]]}
+      end)
+    end)
+
+    it('handles clearing out non-current buffer #24911', function()
+        local buf = meths.get_current_buf()
+        meths.buf_set_lines(buf, 0, -1, true, {"aaa", "bbb", "ccc"})
+        command("new")
+
+        meths.buf_set_lines(0, 0, -1, true, {"xxx", "yyy", "zzz"})
+
+        meths.buf_set_lines(buf, 0, -1, true, {})
+        eq({"xxx", "yyy", "zzz"}, meths.buf_get_lines(0, 0, -1, true))
+        eq({''}, meths.buf_get_lines(buf, 0, -1, true))
+    end)
   end)
 
   describe('deprecated: {get,set,del}_line', function()
@@ -193,7 +513,7 @@ describe('api/buf', function()
 
     it('fails correctly when input is not valid', function()
       eq(1, api.curbufmeths.get_number())
-      eq([[String cannot contain newlines]],
+      eq([['replacement string' item contains newlines]],
         pcall_err(bufmeths.set_lines, 1, 1, 2, false, {'b\na'}))
     end)
 
@@ -393,6 +713,21 @@ describe('api/buf', function()
       feed('<c-w>p')
       eq(3, funcs.winnr())
     end)
+
+    it('set_lines on unloaded buffer #8659 #22670', function()
+      local bufnr = curbuf('get_number')
+      meths.buf_set_lines(bufnr, 0, -1, false, {'a', 'b', 'c'})
+      meths.buf_set_name(bufnr, 'set_lines')
+      finally(function()
+        os.remove('set_lines')
+      end)
+      command('write!')
+      command('new')
+      command('bunload! '..bufnr)
+      local new_bufnr = funcs.bufnr('set_lines', true)
+      meths.buf_set_lines(new_bufnr, 0, -1, false, {})
+      eq({''}, meths.buf_get_lines(new_bufnr, 0, -1, false))
+    end)
   end)
 
   describe('nvim_buf_set_text', function()
@@ -437,6 +772,10 @@ describe('api/buf', function()
       -- can append to a line
       set_text(1, 4, -1, 4, {' and', 'more'})
       eq({'goodbye bar', 'text and', 'more'}, get_lines(0, 3, true))
+
+      -- can use negative column numbers
+      set_text(0, -5, 0, -1, {'!'})
+      eq({'goodbye!'}, get_lines(0, 1, true))
     end)
 
     it('works with undo', function()
@@ -480,6 +819,754 @@ describe('api/buf', function()
       eq({1, 9}, curwin('get_cursor'))
     end)
 
+    it('updates the cursor position in non-current window', function()
+      insert([[
+      hello world!]])
+
+      -- position the cursor on `!`
+      meths.win_set_cursor(0, {1, 11})
+
+      local win = meths.get_current_win()
+      local buf = meths.get_current_buf()
+
+      command("new")
+
+      -- replace 'world' with 'foo'
+      meths.buf_set_text(buf, 0, 6, 0, 11, {'foo'})
+      eq({'hello foo!'}, meths.buf_get_lines(buf, 0, -1, true))
+      -- cursor should be moved left by two columns (replacement is shorter by 2 chars)
+      eq({1, 9}, meths.win_get_cursor(win))
+    end)
+
+    it('updates the cursor position in TWO non-current windows', function()
+      insert([[
+      hello world!]])
+
+      -- position the cursor on `!`
+      meths.win_set_cursor(0, {1, 11})
+      local win = meths.get_current_win()
+      local buf = meths.get_current_buf()
+
+      command("split")
+      local win2 = meths.get_current_win()
+      -- position the cursor on `w`
+      meths.win_set_cursor(0, {1, 6})
+
+      command("new")
+
+      -- replace 'hello' with 'foo'
+      meths.buf_set_text(buf, 0, 0, 0, 5, {'foo'})
+      eq({'foo world!'}, meths.buf_get_lines(buf, 0, -1, true))
+
+      -- both cursors should be moved left by two columns (replacement is shorter by 2 chars)
+      eq({1, 9}, meths.win_get_cursor(win))
+      eq({1, 4}, meths.win_get_cursor(win2))
+    end)
+
+    describe('when text is being added right at cursor position #22526', function()
+      it('updates the cursor position in NORMAL mode', function()
+        insert([[
+        abcd]])
+
+        -- position the cursor on 'c'
+        curwin('set_cursor', {1, 2})
+        -- add 'xxx' before 'c'
+        set_text(0, 2, 0, 2, {'xxx'})
+        eq({'abxxxcd'}, get_lines(0, -1, true))
+        -- cursor should be on 'c'
+        eq({1, 5}, curwin('get_cursor'))
+      end)
+
+      it('updates the cursor position only in non-current window when in INSERT mode', function()
+        insert([[
+        abcd]])
+
+        -- position the cursor on 'c'
+        curwin('set_cursor', {1, 2})
+        -- open vertical split
+        feed('<c-w>v')
+        -- get into INSERT mode to treat cursor
+        -- as being after 'b', not on 'c'
+        feed('i')
+        -- add 'xxx' between 'b' and 'c'
+        set_text(0, 2, 0, 2, {'xxx'})
+        eq({'abxxxcd'}, get_lines(0, -1, true))
+        -- in the current window cursor should stay after 'b'
+        eq({1, 2}, curwin('get_cursor'))
+        -- quit INSERT mode
+        feed('<esc>')
+        -- close current window
+        feed('<c-w>c')
+        -- in another window cursor should be on 'c'
+        eq({1, 5}, curwin('get_cursor'))
+      end)
+    end)
+
+    describe('when text is being deleted right at cursor position', function()
+      it('leaves cursor at the same position in NORMAL mode', function()
+        insert([[
+        abcd]])
+
+        -- position the cursor on 'b'
+        curwin('set_cursor', {1, 1})
+        -- delete 'b'
+        set_text(0, 1, 0, 2, {})
+        eq({'acd'}, get_lines(0, -1, true))
+        -- cursor is now on 'c'
+        eq({1, 1}, curwin('get_cursor'))
+      end)
+
+      it('leaves cursor at the same position in INSERT mode in current and non-current window', function()
+        insert([[
+        abcd]])
+
+        -- position the cursor on 'b'
+        curwin('set_cursor', {1, 1})
+        -- open vertical split
+        feed('<c-w>v')
+        -- get into INSERT mode to treat cursor
+        -- as being after 'a', not on 'b'
+        feed('i')
+        -- delete 'b'
+        set_text(0, 1, 0, 2, {})
+        eq({'acd'}, get_lines(0, -1, true))
+        -- cursor in the current window should stay after 'a'
+        eq({1, 1}, curwin('get_cursor'))
+        -- quit INSERT mode
+        feed('<esc>')
+        -- close current window
+        feed('<c-w>c')
+        -- cursor in non-current window should stay on 'c'
+        eq({1, 1}, curwin('get_cursor'))
+      end)
+    end)
+
+    describe('when cursor is inside replaced row range', function()
+      it('keeps cursor at the same position if cursor is at start_row, but before start_col', function()
+        insert([[
+        This should be first
+        then there is a line we do not want
+        and finally the last one]])
+
+        -- position the cursor on ' ' before 'first'
+        curwin('set_cursor', {1, 14})
+
+        set_text(0, 15, 2, 11, {
+          'the line we do not want',
+          'but hopefully',
+        })
+
+        eq({
+          'This should be the line we do not want',
+          'but hopefully the last one',
+        }, get_lines(0, -1, true))
+        -- cursor should stay at the same position
+        eq({1, 14}, curwin('get_cursor'))
+      end)
+
+      it('keeps cursor at the same position if cursor is at start_row and column is still valid', function()
+        insert([[
+        This should be first
+        then there is a line we do not want
+        and finally the last one]])
+
+        -- position the cursor on 'f' in 'first'
+        curwin('set_cursor', {1, 15})
+
+        set_text(0, 15, 2, 11, {
+          'the line we do not want',
+          'but hopefully',
+        })
+
+        eq({
+          'This should be the line we do not want',
+          'but hopefully the last one',
+        }, get_lines(0, -1, true))
+        -- cursor should stay at the same position
+        eq({1, 15}, curwin('get_cursor'))
+      end)
+
+      it('adjusts cursor column to keep it valid if start_row got smaller', function()
+        insert([[
+        This should be first
+        then there is a line we do not want
+        and finally the last one]])
+
+        -- position the cursor on 't' in 'first'
+        curwin('set_cursor', {1, 19})
+
+        local cursor = exec_lua([[
+          vim.api.nvim_buf_set_text(0, 0, 15, 2, 24, {'last'})
+          return vim.api.nvim_win_get_cursor(0)
+        ]])
+
+        eq({ 'This should be last' }, get_lines(0, -1, true))
+        -- cursor should end up on 't' in 'last'
+        eq({1, 18}, curwin('get_cursor'))
+        -- immediate call to nvim_win_get_cursor should have returned the same position
+        eq({1, 18}, cursor)
+      end)
+
+      it('adjusts cursor column to keep it valid if start_row got smaller in INSERT mode', function()
+        insert([[
+        This should be first
+        then there is a line we do not want
+        and finally the last one]])
+
+        -- position the cursor on 't' in 'first'
+        curwin('set_cursor', {1, 19})
+        -- enter INSERT mode to treat cursor as being after 't'
+        feed('a')
+
+        local cursor = exec_lua([[
+          vim.api.nvim_buf_set_text(0, 0, 15, 2, 24, {'last'})
+          return vim.api.nvim_win_get_cursor(0)
+        ]])
+
+        eq({ 'This should be last' }, get_lines(0, -1, true))
+        -- cursor should end up after 't' in 'last'
+        eq({1, 19}, curwin('get_cursor'))
+        -- immediate call to nvim_win_get_cursor should have returned the same position
+        eq({1, 19}, cursor)
+      end)
+
+      it('adjusts cursor column to keep it valid in a row after start_row if it got smaller', function()
+        insert([[
+        This should be first
+        then there is a line we do not want
+        and finally the last one]])
+
+        -- position the cursor on 'w' in 'want'
+        curwin('set_cursor', {2, 31})
+
+        local cursor = exec_lua([[
+          vim.api.nvim_buf_set_text(0, 0, 15, 2, 11, {
+            '1',
+            'then 2',
+            'and then',
+          })
+          return vim.api.nvim_win_get_cursor(0)
+        ]])
+
+        eq({
+          'This should be 1',
+          'then 2',
+          'and then the last one',
+        }, get_lines(0, -1, true))
+        -- cursor column should end up at the end of a row
+        eq({2, 5}, curwin('get_cursor'))
+        -- immediate call to nvim_win_get_cursor should have returned the same position
+        eq({2, 5}, cursor)
+      end)
+
+      it('adjusts cursor column to keep it valid in a row after start_row if it got smaller in INSERT mode', function()
+        insert([[
+        This should be first
+        then there is a line we do not want
+        and finally the last one]])
+
+        -- position the cursor on 'w' in 'want'
+        curwin('set_cursor', {2, 31})
+        -- enter INSERT mode
+        feed('a')
+
+        local cursor = exec_lua([[
+          vim.api.nvim_buf_set_text(0, 0, 15, 2, 11, {
+            '1',
+            'then 2',
+            'and then',
+          })
+          return vim.api.nvim_win_get_cursor(0)
+        ]])
+
+        eq({
+          'This should be 1',
+          'then 2',
+          'and then the last one',
+        }, get_lines(0, -1, true))
+        -- cursor column should end up at the end of a row
+        eq({2, 6}, curwin('get_cursor'))
+        -- immediate call to nvim_win_get_cursor should have returned the same position
+        eq({2, 6}, cursor)
+      end)
+
+      it('adjusts cursor line and column to keep it inside replacement range', function()
+        insert([[
+        This should be first
+        then there is a line we do not want
+        and finally the last one]])
+
+        -- position the cursor on 'n' in 'finally'
+        curwin('set_cursor', {3, 6})
+
+        local cursor = exec_lua([[
+          vim.api.nvim_buf_set_text(0, 0, 15, 2, 11, {
+            'the line we do not want',
+            'but hopefully',
+          })
+          return vim.api.nvim_win_get_cursor(0)
+        ]])
+
+        eq({
+          'This should be the line we do not want',
+          'but hopefully the last one',
+        }, get_lines(0, -1, true))
+        -- cursor should end up on 'y' in 'hopefully'
+        -- to stay in the range, because it got smaller
+        eq({2, 12}, curwin('get_cursor'))
+        -- immediate call to nvim_win_get_cursor should have returned the same position
+        eq({2, 12}, cursor)
+      end)
+
+      it('adjusts cursor line and column if replacement is empty', function()
+        insert([[
+        This should be first
+        then there is a line we do not want
+        and finally the last one]])
+
+        -- position the cursor on 'r' in 'there'
+        curwin('set_cursor', {2, 8})
+
+        local cursor = exec_lua([[
+          vim.api.nvim_buf_set_text(0, 0, 15, 2, 12, {})
+          return vim.api.nvim_win_get_cursor(0)
+        ]])
+
+        eq({ 'This should be the last one' }, get_lines(0, -1, true))
+        -- cursor should end up on the next column after deleted range
+        eq({1, 15}, curwin('get_cursor'))
+        -- immediate call to nvim_win_get_cursor should have returned the same position
+        eq({1, 15}, cursor)
+      end)
+
+      it('adjusts cursor line and column if replacement is empty and start_col == 0', function()
+        insert([[
+        This should be first
+        then there is a line we do not want
+        and finally the last one]])
+
+        -- position the cursor on 'r' in 'there'
+        curwin('set_cursor', {2, 8})
+
+        local cursor = exec_lua([[
+          vim.api.nvim_buf_set_text(0, 0, 0, 2, 4, {})
+          return vim.api.nvim_win_get_cursor(0)
+        ]])
+
+        eq({ 'finally the last one' }, get_lines(0, -1, true))
+        -- cursor should end up in column 0
+        eq({1, 0}, curwin('get_cursor'))
+        -- immediate call to nvim_win_get_cursor should have returned the same position
+        eq({1, 0}, cursor)
+      end)
+
+      it('adjusts cursor column if replacement ends at cursor row, after cursor column', function()
+        insert([[
+        This should be first
+        then there is a line we do not want
+        and finally the last one]])
+
+        -- position the cursor on 'y' in 'finally'
+        curwin('set_cursor', {3, 10})
+        set_text(0, 15, 2, 11, { '1', 'this 2', 'and then' })
+
+        eq({
+          'This should be 1',
+          'this 2',
+          'and then the last one',
+        }, get_lines(0, -1, true))
+        -- cursor should end up on 'n' in 'then'
+        eq({3, 7}, curwin('get_cursor'))
+      end)
+
+      it('adjusts cursor column if replacement ends at cursor row, at cursor column in INSERT mode', function()
+        insert([[
+        This should be first
+        then there is a line we do not want
+        and finally the last one]])
+
+        -- position the cursor on 'y' at 'finally'
+        curwin('set_cursor', {3, 10})
+        -- enter INSERT mode to treat cursor as being between 'l' and 'y'
+        feed('i')
+        set_text(0, 15, 2, 11, { '1', 'this 2', 'and then' })
+
+        eq({
+          'This should be 1',
+          'this 2',
+          'and then the last one',
+        }, get_lines(0, -1, true))
+        -- cursor should end up after 'n' in 'then'
+        eq({3, 8}, curwin('get_cursor'))
+      end)
+
+      it('adjusts cursor column if replacement is inside of a single line', function()
+        insert([[
+        This should be first
+        then there is a line we do not want
+        and finally the last one]])
+
+        -- position the cursor on 'y' in 'finally'
+        curwin('set_cursor', {3, 10})
+        set_text(2, 4, 2, 11, { 'then' })
+
+        eq({
+          'This should be first',
+          'then there is a line we do not want',
+          'and then the last one',
+        }, get_lines(0, -1, true))
+        -- cursor should end up on 'n' in 'then'
+        eq({3, 7}, curwin('get_cursor'))
+      end)
+
+      it('does not move cursor column after end of a line', function()
+        insert([[
+        This should be the only line here
+        !!!]])
+
+        -- position cursor on the last '1'
+        curwin('set_cursor', {2, 2})
+
+        local cursor = exec_lua([[
+          vim.api.nvim_buf_set_text(0, 0, 33, 1, 3, {})
+          return vim.api.nvim_win_get_cursor(0)
+        ]])
+
+        eq({ 'This should be the only line here' }, get_lines(0, -1, true))
+        -- cursor should end up on '!'
+        eq({1, 32}, curwin('get_cursor'))
+        -- immediate call to nvim_win_get_cursor should have returned the same position
+        eq({1, 32}, cursor)
+      end)
+
+      it('does not move cursor column before start of a line', function()
+        insert('\n!!!')
+
+        -- position cursor on the last '1'
+        curwin('set_cursor', {2, 2})
+
+        local cursor = exec_lua([[
+          vim.api.nvim_buf_set_text(0, 0, 0, 1, 3, {})
+          return vim.api.nvim_win_get_cursor(0)
+        ]])
+
+        eq({ '' }, get_lines(0, -1, true))
+        -- cursor should end up on '!'
+        eq({1, 0}, curwin('get_cursor'))
+        -- immediate call to nvim_win_get_cursor should have returned the same position
+        eq({1, 0}, cursor)
+      end)
+
+      describe('with virtualedit', function()
+        it('adjusts cursor line and column to keep it inside replacement range if cursor is not after eol', function()
+          insert([[
+          This should be first
+          then there is a line we do not want
+          and finally the last one]])
+
+          -- position cursor on 't' in 'want'
+          curwin('set_cursor', {2, 34})
+          -- turn on virtualedit
+          command('set virtualedit=all')
+
+          local cursor = exec_lua([[
+            vim.api.nvim_buf_set_text(0, 0, 15, 2, 11, {
+              'the line we do not want',
+              'but hopefully',
+            })
+            return vim.api.nvim_win_get_cursor(0)
+          ]])
+
+          eq({
+            'This should be the line we do not want',
+            'but hopefully the last one',
+          }, get_lines(0, -1, true))
+          -- cursor should end up on 'y' in 'hopefully'
+          -- to stay in the range
+          eq({2, 12}, curwin('get_cursor'))
+          -- immediate call to nvim_win_get_cursor should have returned the same position
+          eq({2, 12}, cursor)
+          -- coladd should be 0
+          eq(0, exec_lua([[
+            return vim.fn.winsaveview().coladd
+          ]]))
+        end)
+
+        it('does not change cursor screen column when cursor is after eol and row got shorter', function()
+          insert([[
+          This should be first
+          then there is a line we do not want
+          and finally the last one]])
+
+          -- position cursor on 't' in 'want'
+          curwin('set_cursor', {2, 34})
+          -- turn on virtualedit
+          command('set virtualedit=all')
+          -- move cursor after eol
+          exec_lua([[
+            vim.fn.winrestview({ coladd = 5 })
+          ]])
+
+          local cursor = exec_lua([[
+            vim.api.nvim_buf_set_text(0, 0, 15, 2, 11, {
+              'the line we do not want',
+              'but hopefully',
+            })
+            return vim.api.nvim_win_get_cursor(0)
+          ]])
+
+          eq({
+            'This should be the line we do not want',
+            'but hopefully the last one',
+          }, get_lines(0, -1, true))
+          -- cursor should end up at eol of a new row
+          eq({2, 26}, curwin('get_cursor'))
+          -- immediate call to nvim_win_get_cursor should have returned the same position
+          eq({2, 26}, cursor)
+          -- coladd should be increased so that cursor stays in the same screen column
+          eq(13, exec_lua([[
+            return vim.fn.winsaveview().coladd
+          ]]))
+        end)
+
+        it('does not change cursor screen column when cursor is after eol and row got longer', function()
+          insert([[
+          This should be first
+          then there is a line we do not want
+          and finally the last one]])
+
+          -- position cursor on 't' in 'first'
+          curwin('set_cursor', {1, 19})
+          -- turn on virtualedit
+          command('set virtualedit=all')
+          -- move cursor after eol
+          exec_lua([[
+            vim.fn.winrestview({ coladd = 21 })
+          ]])
+
+          local cursor = exec_lua([[
+            vim.api.nvim_buf_set_text(0, 0, 15, 2, 11, {
+              'the line we do not want',
+              'but hopefully',
+            })
+            return vim.api.nvim_win_get_cursor(0)
+          ]])
+
+          eq({
+            'This should be the line we do not want',
+            'but hopefully the last one',
+          }, get_lines(0, -1, true))
+          -- cursor should end up at eol of a new row
+          eq({1, 38}, curwin('get_cursor'))
+          -- immediate call to nvim_win_get_cursor should have returned the same position
+          eq({1, 38}, cursor)
+          -- coladd should be increased so that cursor stays in the same screen column
+          eq(2, exec_lua([[
+            return vim.fn.winsaveview().coladd
+          ]]))
+        end)
+
+        it('does not change cursor screen column when cursor is after eol and row extended past cursor column', function()
+          insert([[
+          This should be first
+          then there is a line we do not want
+          and finally the last one]])
+
+          -- position cursor on 't' in 'first'
+          curwin('set_cursor', {1, 19})
+          -- turn on virtualedit
+          command('set virtualedit=all')
+          -- move cursor after eol just a bit
+          exec_lua([[
+            vim.fn.winrestview({ coladd = 3 })
+          ]])
+
+          local cursor = exec_lua([[
+            vim.api.nvim_buf_set_text(0, 0, 15, 2, 11, {
+              'the line we do not want',
+              'but hopefully',
+            })
+            return vim.api.nvim_win_get_cursor(0)
+          ]])
+
+          eq({
+            'This should be the line we do not want',
+            'but hopefully the last one',
+          }, get_lines(0, -1, true))
+          -- cursor should stay at the same screen column
+          eq({1, 22}, curwin('get_cursor'))
+          -- immediate call to nvim_win_get_cursor should have returned the same position
+          eq({1, 22}, cursor)
+          -- coladd should become 0
+          eq(0, exec_lua([[
+            return vim.fn.winsaveview().coladd
+          ]]))
+        end)
+
+        it('does not change cursor screen column when cursor is after eol and row range decreased', function()
+          insert([[
+          This should be first
+          then there is a line we do not want
+          and one more
+          and finally the last one]])
+
+          -- position cursor on 'e' in 'more'
+          curwin('set_cursor', {3, 11})
+          -- turn on virtualedit
+          command('set virtualedit=all')
+          -- move cursor after eol
+          exec_lua([[
+            vim.fn.winrestview({ coladd = 28 })
+          ]])
+
+          local cursor = exec_lua([[
+            vim.api.nvim_buf_set_text(0, 0, 15, 3, 11, {
+              'the line we do not want',
+              'but hopefully',
+            })
+            return vim.api.nvim_win_get_cursor(0)
+          ]])
+
+          eq({
+            'This should be the line we do not want',
+            'but hopefully the last one',
+          }, get_lines(0, -1, true))
+          -- cursor should end up at eol of a new row
+          eq({2, 26}, curwin('get_cursor'))
+          -- immediate call to nvim_win_get_cursor should have returned the same position
+          eq({2, 26}, cursor)
+          -- coladd should be increased so that cursor stays in the same screen column
+          eq(13, exec_lua([[
+            return vim.fn.winsaveview().coladd
+          ]]))
+        end)
+      end)
+    end)
+
+    describe('when cursor is at end_row and after end_col', function()
+      it('adjusts cursor column when only a newline is added or deleted', function()
+        insert([[
+        first line
+        second
+         line]])
+
+        -- position the cursor on 'i'
+        curwin('set_cursor', {3, 2})
+        set_text(1, 6, 2, 0, {})
+        eq({'first line', 'second line'}, get_lines(0, -1, true))
+        -- cursor should stay on 'i'
+        eq({2, 8}, curwin('get_cursor'))
+
+        -- add a newline back
+        set_text(1, 6, 1, 6, {'', ''})
+        eq({'first line', 'second', ' line'}, get_lines(0, -1, true))
+        -- cursor should return back to the original position
+        eq({3, 2}, curwin('get_cursor'))
+      end)
+
+      it('adjusts cursor column if the range is not bound to either start or end of a line', function()
+        insert([[
+        This should be first
+        then there is a line we do not want
+        and finally the last one]])
+
+        -- position the cursor on 'h' in 'the'
+        curwin('set_cursor', {3, 13})
+        set_text(0, 14, 2, 11, {})
+        eq({'This should be the last one'}, get_lines(0, -1, true))
+        -- cursor should stay on 'h'
+        eq({1, 16}, curwin('get_cursor'))
+        -- add deleted lines back
+        set_text(0, 14, 0, 14, {
+          ' first',
+          'then there is a line we do not want',
+          'and finally',
+        })
+        eq({
+          'This should be first',
+          'then there is a line we do not want',
+          'and finally the last one',
+        }, get_lines(0, -1, true))
+        -- cursor should return back to the original position
+        eq({3, 13}, curwin('get_cursor'))
+      end)
+
+      it('adjusts cursor column if replacing lines in range, not just deleting and adding', function()
+        insert([[
+        This should be first
+        then there is a line we do not want
+        and finally the last one]])
+
+        -- position the cursor on 's' in 'last'
+        curwin('set_cursor', {3, 18})
+        set_text(0, 15, 2, 11, {
+          'the line we do not want',
+          'but hopefully',
+        })
+
+        eq({
+          'This should be the line we do not want',
+          'but hopefully the last one',
+        }, get_lines(0, -1, true))
+        -- cursor should stay on 's'
+        eq({2, 20}, curwin('get_cursor'))
+
+        set_text(0, 15, 1, 13, {
+          'first',
+          'then there is a line we do not want',
+          'and finally',
+        })
+
+        eq({
+          'This should be first',
+          'then there is a line we do not want',
+          'and finally the last one',
+        }, get_lines(0, -1, true))
+        -- cursor should return back to the original position
+        eq({3, 18}, curwin('get_cursor'))
+      end)
+
+      it('does not move cursor column after end of a line', function()
+        insert([[
+        This should be the only line here
+        ]])
+
+        -- position cursor at the empty line
+        curwin('set_cursor', {2, 0})
+
+        local cursor = exec_lua([[
+          vim.api.nvim_buf_set_text(0, 0, 33, 1, 0, {'!'})
+          return vim.api.nvim_win_get_cursor(0)
+        ]])
+
+        eq({ 'This should be the only line here!' }, get_lines(0, -1, true))
+        -- cursor should end up on '!'
+        eq({1, 33}, curwin('get_cursor'))
+        -- immediate call to nvim_win_get_cursor should have returned the same position
+        eq({1, 33}, cursor)
+      end)
+
+      it('does not move cursor column before start of a line', function()
+        insert('\n')
+
+        eq({ '', '' }, get_lines(0, -1, true))
+
+        -- position cursor on the last '1'
+        curwin('set_cursor', {2, 2})
+
+        local cursor = exec_lua([[
+          vim.api.nvim_buf_set_text(0, 0, 0, 1, 0, {''})
+          return vim.api.nvim_win_get_cursor(0)
+        ]])
+
+        eq({ '' }, get_lines(0, -1, true))
+        -- cursor should end up on '!'
+        eq({1, 0}, curwin('get_cursor'))
+        -- immediate call to nvim_win_get_cursor should have returned the same position
+        eq({1, 0}, cursor)
+      end)
+    end)
+
     it('can handle NULs', function()
       set_text(0, 0, 0, 0, {'ab\0cd'})
       eq('ab\0cd', curbuf_depr('get_line', 0))
@@ -553,20 +1640,20 @@ describe('api/buf', function()
       insert([[
       hello foo!
       text]])
-      eq('start_row out of bounds', pcall_err(set_text, 2, 0, 3, 0, {}))
-      eq('start_row out of bounds', pcall_err(set_text, -3, 0, 0, 0, {}))
-      eq('end_row out of bounds', pcall_err(set_text, 0, 0, 2, 0, {}))
-      eq('end_row out of bounds', pcall_err(set_text, 0, 0, -3, 0, {}))
-      eq('start_col out of bounds', pcall_err(set_text, 1, 5, 1, 5, {}))
-      eq('end_col out of bounds', pcall_err(set_text, 1, 0, 1, 5, {}))
+      eq("Invalid 'start_row': out of range", pcall_err(set_text, 2, 0, 3, 0, {}))
+      eq("Invalid 'start_row': out of range", pcall_err(set_text, -3, 0, 0, 0, {}))
+      eq("Invalid 'end_row': out of range", pcall_err(set_text, 0, 0, 2, 0, {}))
+      eq("Invalid 'end_row': out of range", pcall_err(set_text, 0, 0, -3, 0, {}))
+      eq("Invalid 'start_col': out of range", pcall_err(set_text, 1, 5, 1, 5, {}))
+      eq("Invalid 'end_col': out of range", pcall_err(set_text, 1, 0, 1, 5, {}))
     end)
 
     it('errors when start is greater than end', function()
       insert([[
       hello foo!
       text]])
-      eq('start is higher than end', pcall_err(set_text, 1, 0, 0, 0, {}))
-      eq('start is higher than end', pcall_err(set_text, 0, 1, 0, 0, {}))
+      eq("'start' is higher than 'end'", pcall_err(set_text, 1, 0, 0, 0, {}))
+      eq("'start' is higher than 'end'", pcall_err(set_text, 0, 1, 0, 0, {}))
     end)
 
     it('no heap-use-after-free when called consecutively #19643', function()
@@ -579,6 +1666,139 @@ describe('api/buf', function()
       ]])
       eq({'one', 'two'}, get_lines(0, 2, true))
     end)
+
+    describe('handles topline', function()
+      local screen
+      before_each(function()
+        screen = Screen.new(20, 12)
+        screen:set_default_attr_ids {
+          [1] = {bold = true, foreground = Screen.colors.Blue1};
+          [2] = {reverse = true, bold = true};
+          [3] = {reverse = true};
+        }
+        screen:attach()
+        meths.buf_set_lines(0, 0, -1, 1, {"aaa", "bbb", "ccc", "ddd", "www", "xxx", "yyy", "zzz"})
+        meths.set_option_value('modified', false, {})
+      end)
+
+      it('of current window', function()
+        local win = meths.get_current_win()
+        local buf = meths.get_current_buf()
+
+        command('new | wincmd w')
+        meths.win_set_cursor(win, {8,0})
+
+        screen:expect{grid=[[
+                              |
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {3:[No Name]           }|
+          www                 |
+          xxx                 |
+          yyy                 |
+          ^zzz                 |
+          {2:[No Name]           }|
+                              |
+        ]]}
+        meths.buf_set_text(buf, 0,3, 1,0, {"X"})
+
+        screen:expect{grid=[[
+                              |
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {3:[No Name]           }|
+          www                 |
+          xxx                 |
+          yyy                 |
+          ^zzz                 |
+          {2:[No Name] [+]       }|
+                              |
+        ]]}
+      end)
+
+      it('of non-current window', function()
+        local win = meths.get_current_win()
+        local buf = meths.get_current_buf()
+
+        command('new')
+        meths.win_set_cursor(win, {8,0})
+
+        screen:expect{grid=[[
+          ^                    |
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {2:[No Name]           }|
+          www                 |
+          xxx                 |
+          yyy                 |
+          zzz                 |
+          {3:[No Name]           }|
+                              |
+        ]]}
+
+        meths.buf_set_text(buf, 0,3, 1,0, {"X"})
+        screen:expect{grid=[[
+          ^                    |
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {1:~                   }|
+          {2:[No Name]           }|
+          www                 |
+          xxx                 |
+          yyy                 |
+          zzz                 |
+          {3:[No Name] [+]       }|
+                              |
+        ]]}
+      end)
+
+      it('of split windows with same buffer', function()
+        local win = meths.get_current_win()
+        local buf = meths.get_current_buf()
+
+        command('split')
+        meths.win_set_cursor(win, {8,0})
+        meths.win_set_cursor(0, {1,1})
+
+        screen:expect{grid=[[
+          a^aa                 |
+          bbb                 |
+          ccc                 |
+          ddd                 |
+          www                 |
+          {2:[No Name]           }|
+          www                 |
+          xxx                 |
+          yyy                 |
+          zzz                 |
+          {3:[No Name]           }|
+                              |
+        ]]}
+        meths.buf_set_text(buf, 0,3, 1,0, {"X"})
+
+        screen:expect{grid=[[
+          a^aaXbbb             |
+          ccc                 |
+          ddd                 |
+          www                 |
+          xxx                 |
+          {2:[No Name] [+]       }|
+          www                 |
+          xxx                 |
+          yyy                 |
+          zzz                 |
+          {3:[No Name] [+]       }|
+                              |
+        ]]}
+      end)
+    end)
   end)
 
   describe_lua_and_rpc('nvim_buf_get_text', function(api)
@@ -611,7 +1831,7 @@ describe('api/buf', function()
     end)
 
     it('errors when start is greater than end', function()
-      eq('start is higher than end', pcall_err(get_text, 1, 0, 0, 0, {}))
+      eq("'start' is higher than 'end'", pcall_err(get_text, 1, 0, 0, 0, {}))
       eq('start_col must be less than end_col', pcall_err(get_text, 0, 1, 0, 0, {}))
     end)
   end)
@@ -630,19 +1850,19 @@ describe('api/buf', function()
       eq('Index out of bounds', pcall_err(get_offset, 6))
       eq('Index out of bounds', pcall_err(get_offset, -1))
 
-      curbufmeths.set_option('eol', false)
-      curbufmeths.set_option('fixeol', false)
+      meths.set_option_value('eol', false, {})
+      meths.set_option_value('fixeol', false, {})
       eq(28, get_offset(5))
 
       -- fileformat is ignored
-      curbufmeths.set_option('fileformat', 'dos')
+      meths.set_option_value('fileformat', 'dos', {})
       eq(0, get_offset(0))
       eq(6, get_offset(1))
       eq(15, get_offset(2))
       eq(16, get_offset(3))
       eq(24, get_offset(4))
       eq(28, get_offset(5))
-      curbufmeths.set_option('eol', true)
+      meths.set_option_value('eol', true, {})
       eq(29, get_offset(5))
 
       command("set hidden")
@@ -650,6 +1870,18 @@ describe('api/buf', function()
       eq(6, bufmeths.get_offset(1,1))
       command("bunload! 1")
       eq(-1, bufmeths.get_offset(1,1))
+      eq(-1, bufmeths.get_offset(1,0))
+    end)
+
+    it('works in empty buffer', function()
+      eq(0, get_offset(0))
+      eq(1, get_offset(1))
+    end)
+
+    it('works in buffer with one line inserted', function()
+      feed('itext')
+      eq(0, get_offset(0))
+      eq(5, get_offset(1))
     end)
   end)
 
@@ -697,23 +1929,23 @@ describe('api/buf', function()
     end)
   end)
 
-  describe('nvim_buf_get_option, nvim_buf_set_option', function()
+  describe('nvim_get_option_value, nvim_set_option_value', function()
     it('works', function()
-      eq(8, curbuf('get_option', 'shiftwidth'))
-      curbuf('set_option', 'shiftwidth', 4)
-      eq(4, curbuf('get_option', 'shiftwidth'))
+      eq(8, nvim('get_option_value', 'shiftwidth', {}))
+      nvim('set_option_value', 'shiftwidth', 4, {})
+      eq(4, nvim('get_option_value', 'shiftwidth', {}))
       -- global-local option
-      curbuf('set_option', 'define', 'test')
-      eq('test', curbuf('get_option', 'define'))
+      nvim('set_option_value', 'define', 'test', {buf = 0})
+      eq('test', nvim('get_option_value', 'define', {buf = 0}))
       -- Doesn't change the global value
-      eq([[^\s*#\s*define]], nvim('get_option', 'define'))
+      eq("", nvim('get_option_value', 'define', {scope='global'}))
     end)
 
     it('returns values for unset local options', function()
       -- 'undolevels' is only set to its "unset" value when a new buffer is
       -- created
       command('enew')
-      eq(-123456, curbuf('get_option', 'undolevels'))
+      eq(-123456, nvim('get_option_value', 'undolevels', {buf=0}))
     end)
   end)
 
diff --git a/test/functional/api/buffer_updates_spec.lua b/test/functional/api/buffer_updates_spec.lua
index d5f06c8f1f..80e29c1ff2 100644
--- a/test/functional/api/buffer_updates_spec.lua
+++ b/test/functional/api/buffer_updates_spec.lua
@@ -75,7 +75,7 @@ local function reopenwithfolds(b)
   local tick = reopen(b, origlines)
 
   -- use markers for folds, make all folds open by default
-  command('setlocal foldmethod=marker foldlevel=20')
+  command('setlocal foldmethod=marker foldlevel=20 commentstring=/*%s*/')
 
   -- add a fold
   command('2,4fold')
@@ -762,7 +762,7 @@ describe('API: buffer events:', function()
   it('returns a proper error on nonempty options dict', function()
     clear()
     local b = editoriginal(false)
-    eq("unexpected key: builtin", pcall_err(buffer, 'attach', b, false, {builtin="asfd"}))
+    eq("Invalid 'opts' key: 'builtin'", pcall_err(buffer, 'attach', b, false, {builtin="asfd"}))
   end)
 
   it('nvim_buf_attach returns response after delay #8634', function()
diff --git a/test/functional/api/command_spec.lua b/test/functional/api/command_spec.lua
index d0fb26edc7..1ddb289ded 100644
--- a/test/functional/api/command_spec.lua
+++ b/test/functional/api/command_spec.lua
@@ -24,7 +24,7 @@ describe('nvim_get_commands', function()
     eq({}, meths.get_commands({builtin=false}))
   end)
 
-  it('validates input', function()
+  it('validation', function()
     eq('builtin=true not implemented', pcall_err(meths.get_commands,
       {builtin=true}))
     eq("Invalid key: 'foo'", pcall_err(meths.get_commands,
@@ -543,23 +543,19 @@ describe('nvim_create_user_command', function()
   end)
 
   it('does not allow invalid command names', function()
-    matches("'name' must begin with an uppercase letter", pcall_err(exec_lua, [[
+    eq("Invalid command name (must start with uppercase): 'test'", pcall_err(exec_lua, [[
       vim.api.nvim_create_user_command('test', 'echo "hi"', {})
     ]]))
-
-    matches('Invalid command name', pcall_err(exec_lua, [[
+    eq("Invalid command name: 't@'", pcall_err(exec_lua, [[
       vim.api.nvim_create_user_command('t@', 'echo "hi"', {})
     ]]))
-
-    matches('Invalid command name', pcall_err(exec_lua, [[
+    eq("Invalid command name: 'T@st'", pcall_err(exec_lua, [[
       vim.api.nvim_create_user_command('T@st', 'echo "hi"', {})
     ]]))
-
-    matches('Invalid command name', pcall_err(exec_lua, [[
+    eq("Invalid command name: 'Test!'", pcall_err(exec_lua, [[
       vim.api.nvim_create_user_command('Test!', 'echo "hi"', {})
     ]]))
-
-    matches('Invalid command name', pcall_err(exec_lua, [[
+    eq("Invalid command name: '💩'", pcall_err(exec_lua, [[
       vim.api.nvim_create_user_command('💩', 'echo "hi"', {})
     ]]))
   end)
diff --git a/test/functional/api/extmark_spec.lua b/test/functional/api/extmark_spec.lua
index 9902826c72..44a151cf6a 100644
--- a/test/functional/api/extmark_spec.lua
+++ b/test/functional/api/extmark_spec.lua
@@ -11,6 +11,7 @@ local insert = helpers.insert
 local feed = helpers.feed
 local clear = helpers.clear
 local command = helpers.command
+local exec = helpers.exec
 local meths = helpers.meths
 local assert_alive = helpers.assert_alive
 
@@ -101,12 +102,31 @@ describe('API/extmarks', function()
     ns2 = request('nvim_create_namespace', "my-fancy-plugin2")
   end)
 
+  it('validation', function()
+    eq("Invalid 'end_col': expected Integer, got Array", pcall_err(set_extmark, ns, marks[2], 0, 0, { end_col = {}, end_row = 1 }))
+    eq("Invalid 'end_row': expected Integer, got Array", pcall_err(set_extmark, ns, marks[2], 0, 0, { end_col = 1, end_row = {} }))
+    eq("Invalid 'virt_text_pos': expected String, got Integer", pcall_err(set_extmark, ns, marks[2], 0, 0, { virt_text_pos = 0 }))
+    eq("Invalid 'virt_text_pos': 'foo'", pcall_err(set_extmark, ns, marks[2], 0, 0, { virt_text_pos = 'foo' }))
+    eq("Invalid 'hl_mode': expected String, got Integer", pcall_err(set_extmark, ns, marks[2], 0, 0, { hl_mode = 0 }))
+    eq("Invalid 'hl_mode': 'foo'", pcall_err(set_extmark, ns, marks[2], 0, 0, { hl_mode = 'foo' }))
+    eq("Invalid 'id': expected Integer, got Array", pcall_err(set_extmark, ns, {}, 0, 0, { end_col = 1, end_row = 1 }))
+    eq("Invalid mark position: expected 2 Integer items", pcall_err(get_extmarks, ns, {}, {-1, -1}))
+    eq("Invalid mark position: expected mark id Integer or 2-item Array", pcall_err(get_extmarks, ns, true, {-1, -1}))
+    -- No memory leak with virt_text, virt_lines, sign_text
+    eq("right_gravity is not a boolean", pcall_err(set_extmark, ns, marks[2], 0, 0, {
+      virt_text = {{'foo', 'Normal'}},
+      virt_lines = {{{'bar', 'Normal'}}},
+      sign_text = 'a',
+      right_gravity = 'baz',
+    }))
+  end)
+
   it("can end extranges past final newline using end_col = 0", function()
     set_extmark(ns, marks[1], 0, 0, {
       end_col = 0,
       end_row = 1
     })
-    eq("end_col value outside range",
+    eq("Invalid 'end_col': out of range",
        pcall_err(set_extmark, ns, marks[2], 0, 0, { end_col = 1, end_row = 1 }))
   end)
 
@@ -188,6 +208,23 @@ describe('API/extmarks', function()
     eq({}, get_extmarks(ns2, {0, 0}, {-1, -1}))
   end)
 
+  it('can undo with extmarks (#25147)', function()
+    feed('itest<esc>')
+    set_extmark(ns, 1, 0, 0)
+    set_extmark(ns, 2, 1, 0)
+    eq({ { 1, 0, 0 }, { 2, 1, 0 } }, get_extmarks(ns, {0, 0}, {-1, -1}))
+    feed('dd')
+    eq({ { 1, 1, 0 }, { 2, 1, 0 } }, get_extmarks(ns, {0, 0}, {-1, -1}))
+    curbufmeths.clear_namespace(ns, 0, -1)
+    eq({}, get_extmarks(ns, {0, 0}, {-1, -1}))
+    set_extmark(ns, 1, 0, 0, { right_gravity = false })
+    set_extmark(ns, 2, 1, 0, { right_gravity = false })
+    eq({ { 1, 0, 0 }, { 2, 1, 0 } }, get_extmarks(ns, {0, 0}, {-1, -1}))
+    feed('u')
+    eq({ { 1, 0, 0 }, { 2, 1, 0 } }, get_extmarks(ns, {0, 0}, {-1, -1}))
+    curbufmeths.clear_namespace(ns, 0, -1)
+  end)
+
   it('querying for information and ranges', function()
     --marks = {1, 2, 3}
     --positions = {{0, 0,}, {0, 2}, {0, 3}}
@@ -733,7 +770,14 @@ describe('API/extmarks', function()
       })
     end)
 
-    -- TODO(bfredl): add more tests!
+    it('can get overlapping extmarks', function()
+      set_extmark(ns, 1, 0, 0, {end_row = 5, end_col=0})
+      set_extmark(ns, 2, 2, 5, {end_row = 2, end_col=30})
+      set_extmark(ns, 3, 0, 5, {end_row = 2, end_col=10})
+      set_extmark(ns, 4, 0, 0, {end_row = 1, end_col=0})
+      eq({{ 2, 2, 5 }}, get_extmarks(ns, {2, 0}, {2, -1}, { overlap=false }))
+      eq({{ 1, 0, 0 }, { 3, 0, 5}, {2, 2, 5}}, get_extmarks(ns, {2, 0}, {2, -1}, { overlap=true }))
+    end)
   end)
 
   it('replace works', function()
@@ -1344,10 +1388,10 @@ describe('API/extmarks', function()
 
   it('throws consistent error codes', function()
     local ns_invalid = ns2 + 1
-    eq("Invalid ns_id", pcall_err(set_extmark, ns_invalid, marks[1], positions[1][1], positions[1][2]))
-    eq("Invalid ns_id", pcall_err(curbufmeths.del_extmark, ns_invalid, marks[1]))
-    eq("Invalid ns_id", pcall_err(get_extmarks, ns_invalid, positions[1], positions[2]))
-    eq("Invalid ns_id", pcall_err(get_extmark_by_id, ns_invalid, marks[1]))
+    eq("Invalid 'ns_id': 3", pcall_err(set_extmark, ns_invalid, marks[1], positions[1][1], positions[1][2]))
+    eq("Invalid 'ns_id': 3", pcall_err(curbufmeths.del_extmark, ns_invalid, marks[1]))
+    eq("Invalid 'ns_id': 3", pcall_err(get_extmarks, ns_invalid, positions[1], positions[2]))
+    eq("Invalid 'ns_id': 3", pcall_err(get_extmark_by_id, ns_invalid, marks[1]))
   end)
 
   it('when col = line-length, set the mark on eol', function()
@@ -1362,13 +1406,13 @@ describe('API/extmarks', function()
 
   it('when col = line-length, set the mark on eol', function()
     local invalid_col = init_text:len() + 1
-    eq("col value outside range", pcall_err(set_extmark, ns, marks[1], 0, invalid_col))
+    eq("Invalid 'col': out of range", pcall_err(set_extmark, ns, marks[1], 0, invalid_col))
   end)
 
   it('fails when line > line_count', function()
     local invalid_col = init_text:len() + 1
     local invalid_lnum = 3
-    eq('line value outside range', pcall_err(set_extmark, ns, marks[1], invalid_lnum, invalid_col))
+    eq("Invalid 'line': out of range", pcall_err(set_extmark, ns, marks[1], invalid_lnum, invalid_col))
     eq({}, get_extmark_by_id(ns, marks[1]))
   end)
 
@@ -1385,7 +1429,7 @@ describe('API/extmarks', function()
 
   it('in read-only buffer', function()
     command("view! runtime/doc/help.txt")
-    eq(true, curbufmeths.get_option('ro'))
+    eq(true, meths.get_option_value('ro', {}))
     local id = set_extmark(ns, 0, 0, 2)
     eq({{id, 0, 2}}, get_extmarks(ns,0, -1))
   end)
@@ -1398,12 +1442,12 @@ describe('API/extmarks', function()
   end)
 
   it('does not crash with append/delete/undo sequence', function()
-    meths.exec([[
+    exec([[
       let ns = nvim_create_namespace('myplugin')
       call nvim_buf_set_extmark(0, ns, 0, 0, {})
       call append(0, '')
       %delete
-      undo]],false)
+      undo]])
     assert_alive()
   end)
 
@@ -1435,7 +1479,7 @@ describe('API/extmarks', function()
 
     feed('u')
     -- handles pasting
-    meths.exec([[let @a='asdfasdf']], false)
+    exec([[let @a='asdfasdf']])
     feed([["ap]])
     eq({ {1, 0, 0}, {2, 0, 8} },
         meths.buf_get_extmarks(0, ns, 0, -1, {}))
@@ -1447,6 +1491,7 @@ describe('API/extmarks', function()
       end_line = 1
     })
     eq({ {1, 0, 0, {
+      ns_id = 1,
       end_col = 0,
       end_row = 1,
       right_gravity = true,
@@ -1457,57 +1502,184 @@ describe('API/extmarks', function()
   it('in prompt buffer', function()
     feed('dd')
     local id = set_extmark(ns, marks[1], 0, 0, {})
-    curbufmeths.set_option('buftype', 'prompt')
+    meths.set_option_value('buftype', 'prompt', {})
     feed('i<esc>')
     eq({{id, 0, 2}}, get_extmarks(ns, 0, -1))
   end)
 
   it('can get details', function()
     set_extmark(ns, marks[1], 0, 0, {
+      conceal = "c",
+      cursorline_hl_group = "Statement",
       end_col = 0,
-      end_row = 1,
-      right_gravity = false,
       end_right_gravity = true,
-      priority = 0,
+      end_row = 1,
       hl_eol = true,
-      hl_mode = "blend",
       hl_group = "String",
-      virt_text = { { "text", "Statement" } },
-      virt_text_pos = "right_align",
-      virt_text_hide = true,
-      virt_lines = { { { "lines", "Statement" } }},
+      hl_mode = "blend",
+      line_hl_group = "Statement",
+      number_hl_group = "Statement",
+      priority = 0,
+      right_gravity = false,
+      sign_hl_group = "Statement",
+      sign_text = ">>",
+      spell = true,
+      virt_lines = {
+        { { "lines", "Macro" }, { "???" } },
+        { { "stack", { "Type", "Search" } }, { "!!!" } },
+      },
       virt_lines_above = true,
       virt_lines_leftcol = true,
+      virt_text = { { "text", "Macro" }, { "???" }, { "stack", { "Type", "Search" } } },
+      virt_text_hide = true,
+      virt_text_pos = "right_align",
     })
     set_extmark(ns, marks[2], 0, 0, {
       priority = 0,
-      virt_text = { { "text", "Statement" } },
+      virt_text = { { "", "Macro" }, { "", { "Type", "Search" } }, { "" } },
       virt_text_win_col = 1,
     })
     eq({0, 0, {
+      conceal = "c",
+      cursorline_hl_group = "Statement",
       end_col = 0,
-      end_row = 1,
-      right_gravity = false,
       end_right_gravity = true,
-      priority = 0,
+      end_row = 1,
       hl_eol = true,
-      hl_mode = "blend",
       hl_group = "String",
-      virt_text = { { "text", "Statement" } },
-      virt_text_pos = "right_align",
-      virt_text_hide = true,
-      virt_lines = { { { "lines", "Statement" } }},
+      hl_mode = "blend",
+      line_hl_group = "Statement",
+      ns_id = 1,
+      number_hl_group = "Statement",
+      priority = 0,
+      right_gravity = false,
+      sign_hl_group = "Statement",
+      sign_text = ">>",
+      spell = true,
+      virt_lines = {
+        { { "lines", "Macro" }, { "???" } },
+        { { "stack", { "Type", "Search" } }, { "!!!" } },
+      },
       virt_lines_above = true,
       virt_lines_leftcol = true,
+      virt_text = { { "text", "Macro" }, { "???" }, { "stack", { "Type", "Search" } } },
+      virt_text_hide = true,
+      virt_text_pos = "right_align",
     } }, get_extmark_by_id(ns, marks[1], { details = true }))
     eq({0, 0, {
+      ns_id = 1,
       right_gravity = true,
       priority = 0,
-      virt_text = { { "text", "Statement" } },
+      virt_text = { { "", "Macro" }, { "", { "Type", "Search" } }, { "" } },
       virt_text_hide = false,
       virt_text_pos = "win_col",
       virt_text_win_col = 1,
     } }, get_extmark_by_id(ns, marks[2], { details = true }))
+    set_extmark(ns, marks[3], 0, 0, { cursorline_hl_group = "Statement" })
+    eq({0, 0, {
+      ns_id = 1,
+      cursorline_hl_group = "Statement",
+      priority = 4096,
+      right_gravity = true,
+    } }, get_extmark_by_id(ns, marks[3], { details = true }))
+    curbufmeths.clear_namespace(ns, 0, -1)
+    -- legacy sign mark includes sign name
+    command('sign define sign1 text=s1 texthl=Title linehl=LineNR numhl=Normal culhl=CursorLine')
+    command('sign place 1 name=sign1 line=1')
+    eq({ {1, 0, 0, {
+      cursorline_hl_group = 'CursorLine',
+      invalidate = true,
+      line_hl_group = 'LineNr',
+      ns_id = 0,
+      number_hl_group = 'Normal',
+      priority = 10,
+      right_gravity = true,
+      sign_hl_group = 'Title',
+      sign_name = 'sign1',
+      sign_text = 's1',
+      undo_restore = false
+    } } }, get_extmarks(-1, 0, -1, { details = true }))
+  end)
+
+  it('can get marks from anonymous namespaces', function()
+    ns = request('nvim_create_namespace', "")
+    ns2 = request('nvim_create_namespace', "")
+    set_extmark(ns, 1, 0, 0, {})
+    set_extmark(ns2, 2, 1, 0, {})
+    eq({{ 1, 0, 0, { ns_id = ns, right_gravity = true }},
+        { 2, 1, 0, { ns_id = ns2, right_gravity = true }}},
+        get_extmarks(-1, 0, -1, { details = true }))
+  end)
+
+  it('can filter by extmark properties', function()
+    set_extmark(ns, 1, 0, 0, {})
+    set_extmark(ns, 2, 0, 0, { hl_group = 'Normal' })
+    set_extmark(ns, 3, 0, 0, { sign_text = '>>' })
+    set_extmark(ns, 4, 0, 0, { virt_text = {{'text', 'Normal'}}})
+    set_extmark(ns, 5, 0, 0, { virt_lines = {{{ 'line', 'Normal' }}}})
+    eq(5, #get_extmarks(-1, 0, -1, {}))
+    eq({{ 2, 0, 0 }}, get_extmarks(-1, 0, -1, { type = 'highlight' }))
+    eq({{ 3, 0, 0 }}, get_extmarks(-1, 0, -1, { type = 'sign' }))
+    eq({{ 4, 0, 0 }}, get_extmarks(-1, 0, -1, { type = 'virt_text' }))
+    eq({{ 5, 0, 0 }}, get_extmarks(-1, 0, -1, { type = 'virt_lines' }))
+  end)
+
+  it("invalidated marks are deleted", function()
+    screen = Screen.new(40, 6)
+    screen:attach()
+    feed('dd6iaaa bbb ccc<CR><ESC>gg')
+    set_extmark(ns, 1, 0, 0, { invalidate = true, sign_text = 'S1' })
+    set_extmark(ns, 2, 1, 0, { invalidate = true, sign_text = 'S2' })
+    -- mark with invalidate is removed
+    command('d')
+    screen:expect([[
+      S2^aaa bbb ccc                           |
+        aaa bbb ccc                           |
+        aaa bbb ccc                           |
+        aaa bbb ccc                           |
+        aaa bbb ccc                           |
+                                              |
+    ]])
+    -- mark is restored with undo_restore == true
+    command('silent undo')
+    screen:expect([[
+      S1^aaa bbb ccc                           |
+      S2aaa bbb ccc                           |
+        aaa bbb ccc                           |
+        aaa bbb ccc                           |
+        aaa bbb ccc                           |
+                                              |
+    ]])
+    -- mark is deleted with undo_restore == false
+    set_extmark(ns, 1, 0, 0, { invalidate = true, undo_restore = false, sign_text = 'S1' })
+    set_extmark(ns, 2, 1, 0, { invalidate = true, undo_restore = false, sign_text = 'S2' })
+    command('1d 2')
+    eq(0, #get_extmarks(-1, 0, -1, {}))
+    -- mark is not removed when deleting bytes before the range
+    set_extmark(ns, 3, 0, 4, { invalidate = true, undo_restore = false,
+                               hl_group = 'Error', end_col = 7 })
+    feed('dw')
+    eq(3, get_extmark_by_id(ns, 3, { details = true })[3].end_col)
+    -- mark is not removed when deleting bytes at the start of the range
+    feed('x')
+    eq(2, get_extmark_by_id(ns, 3, { details = true })[3].end_col)
+    -- mark is not removed when deleting bytes from the end of the range
+    feed('lx')
+    eq(1, get_extmark_by_id(ns, 3, { details = true})[3].end_col)
+    -- mark is not removed when deleting bytes beyond end of the range
+    feed('x')
+    eq(1, get_extmark_by_id(ns, 3, { details = true})[3].end_col)
+    -- mark is removed when all bytes in the range are deleted
+    feed('hx')
+    eq({}, get_extmark_by_id(ns, 3, {}))
+    -- multiline mark is not removed when start of its range is deleted
+    set_extmark(ns, 4, 1, 4, { undo_restore = false, invalidate = true,
+                               hl_group = 'Error', end_col = 7, end_row = 3 })
+    feed('ddDdd')
+    eq({0, 0}, get_extmark_by_id(ns, 4, {}))
+    -- multiline mark is removed when entirety of its range is deleted
+    feed('vj2ed')
+    eq({}, get_extmark_by_id(ns, 4, {}))
   end)
 end)
 
diff --git a/test/functional/api/highlight_spec.lua b/test/functional/api/highlight_spec.lua
index 7f044977cb..7d7d07e30e 100644
--- a/test/functional/api/highlight_spec.lua
+++ b/test/functional/api/highlight_spec.lua
@@ -57,9 +57,7 @@ describe('API: highlight',function()
     eq(expected_rgb, nvim("get_hl_by_id", hl_id, true))
 
     -- Test invalid id.
-    local err, emsg = pcall(meths.get_hl_by_id, 30000, false)
-    eq(false, err)
-    eq('Invalid highlight id: 30000', string.match(emsg, 'Invalid.*'))
+    eq('Invalid highlight id: 30000', pcall_err(meths.get_hl_by_id, 30000, false))
 
     -- Test all highlight properties.
     command('hi NewHighlight gui=underline,bold,italic,reverse,strikethrough,altfont,nocombine')
@@ -70,22 +68,14 @@ describe('API: highlight',function()
     eq(expected_undercurl, nvim("get_hl_by_id", hl_id, true))
 
     -- Test nil argument.
-    err, emsg = pcall(meths.get_hl_by_id, { nil }, false)
-    eq(false, err)
     eq('Wrong type for argument 1 when calling nvim_get_hl_by_id, expecting Integer',
-       string.match(emsg, 'Wrong.*'))
+       pcall_err(meths.get_hl_by_id, { nil }, false))
 
     -- Test 0 argument.
-    err, emsg = pcall(meths.get_hl_by_id, 0, false)
-    eq(false, err)
-    eq('Invalid highlight id: 0',
-       string.match(emsg, 'Invalid.*'))
+    eq('Invalid highlight id: 0', pcall_err(meths.get_hl_by_id, 0, false))
 
     -- Test -1 argument.
-    err, emsg = pcall(meths.get_hl_by_id, -1, false)
-    eq(false, err)
-    eq('Invalid highlight id: -1',
-       string.match(emsg, 'Invalid.*'))
+    eq('Invalid highlight id: -1', pcall_err(meths.get_hl_by_id, -1, false))
 
     -- Test highlight group without ctermbg value.
     command('hi Normal ctermfg=red ctermbg=yellow')
@@ -119,22 +109,16 @@ describe('API: highlight',function()
     eq(expected_normal, nvim("get_hl_by_name", 'Normal', true))
 
     -- Test invalid name.
-    local err, emsg = pcall(meths.get_hl_by_name , 'unknown_highlight', false)
-    eq(false, err)
-    eq('Invalid highlight name: unknown_highlight',
-       string.match(emsg, 'Invalid.*'))
+    eq("Invalid highlight name: 'unknown_highlight'",
+       pcall_err(meths.get_hl_by_name , 'unknown_highlight', false))
 
     -- Test nil argument.
-    err, emsg = pcall(meths.get_hl_by_name , { nil }, false)
-    eq(false, err)
     eq('Wrong type for argument 1 when calling nvim_get_hl_by_name, expecting String',
-       string.match(emsg, 'Wrong.*'))
+       pcall_err(meths.get_hl_by_name , { nil }, false))
 
     -- Test empty string argument.
-    err, emsg = pcall(meths.get_hl_by_name , '', false)
-    eq(false, err)
-    eq('Invalid highlight name: ',
-       string.match(emsg, 'Invalid.*'))
+    eq('Invalid highlight name',
+       pcall_err(meths.get_hl_by_name , '', false))
 
     -- Test "standout" attribute. #8054
     eq({ underline = true, },
@@ -155,7 +139,7 @@ describe('API: highlight',function()
 
   it('nvim_get_hl_id_by_name', function()
     -- precondition: use a hl group that does not yet exist
-    eq('Invalid highlight name: Shrubbery', pcall_err(meths.get_hl_by_name, "Shrubbery", true))
+    eq("Invalid highlight name: 'Shrubbery'", pcall_err(meths.get_hl_by_name, "Shrubbery", true))
     eq(0, funcs.hlID("Shrubbery"))
 
     local hl_id = meths.get_hl_id_by_name("Shrubbery")
@@ -171,9 +155,9 @@ describe('API: highlight',function()
 
   it("nvim_buf_add_highlight to other buffer doesn't crash if undo is disabled #12873", function()
     command('vsplit file')
-    local err, _ = pcall(meths.buf_set_option, 1, 'undofile', false)
+    local err, _ = pcall(meths.set_option_value, 'undofile', false, { buf = 1 })
     eq(true, err)
-    err, _ = pcall(meths.buf_set_option, 1, 'undolevels', -1)
+    err, _ = pcall(meths.set_option_value, 'undolevels', -1, { buf = 1 })
     eq(true, err)
     err, _ = pcall(meths.buf_add_highlight, 1, -1, 'Question', 0, 0, -1)
     eq(true, err)
@@ -253,25 +237,32 @@ describe("API: set highlight", function()
 
   before_each(clear)
 
-  it ("can set gui highlight", function()
+  it('validation', function()
+    eq("Invalid 'blend': out of range",
+      pcall_err(meths.set_hl, 0, 'Test_hl3', {fg='#FF00FF', blend=999}))
+    eq("Invalid 'blend': expected Integer, got Array",
+      pcall_err(meths.set_hl, 0, 'Test_hl3', {fg='#FF00FF', blend={}}))
+  end)
+
+  it("can set gui highlight", function()
     local ns = get_ns()
     meths.set_hl(ns, 'Test_hl', highlight1)
     eq(highlight1, meths.get_hl_by_name('Test_hl', true))
   end)
 
-  it ("can set cterm highlight", function()
+  it("can set cterm highlight", function()
     local ns = get_ns()
     meths.set_hl(ns, 'Test_hl', highlight2_config)
     eq(highlight2_result, meths.get_hl_by_name('Test_hl', false))
   end)
 
-  it ("can set empty cterm attr", function()
+  it("can set empty cterm attr", function()
     local ns = get_ns()
     meths.set_hl(ns, 'Test_hl', { cterm = {} })
     eq({}, meths.get_hl_by_name('Test_hl', false))
   end)
 
-  it ("cterm attr defaults to gui attr", function()
+  it("cterm attr defaults to gui attr", function()
     local ns = get_ns()
     meths.set_hl(ns, 'Test_hl', highlight1)
     eq({
@@ -280,14 +271,28 @@ describe("API: set highlight", function()
     }, meths.get_hl_by_name('Test_hl', false))
   end)
 
-  it ("can overwrite attr for cterm", function()
+  it("can overwrite attr for cterm", function()
     local ns = get_ns()
     meths.set_hl(ns, 'Test_hl', highlight3_config)
     eq(highlight3_result_gui, meths.get_hl_by_name('Test_hl', true))
     eq(highlight3_result_cterm, meths.get_hl_by_name('Test_hl', false))
   end)
 
-  it ("can set a highlight in the global namespace", function()
+  it("only allows one underline attribute #22371", function()
+    local ns = get_ns()
+    meths.set_hl(ns, 'Test_hl', {
+      underdouble = true,
+      underdotted = true,
+      cterm = {
+        underline = true,
+        undercurl = true,
+      },
+    })
+    eq({ undercurl = true }, meths.get_hl_by_name('Test_hl', false))
+    eq({ underdotted = true }, meths.get_hl_by_name('Test_hl', true))
+  end)
+
+  it("can set a highlight in the global namespace", function()
     meths.set_hl(0, 'Test_hl', highlight2_config)
     eq('Test_hl        xxx cterm=underline,reverse ctermfg=8 ctermbg=15 gui=underline,reverse',
       exec_capture('highlight Test_hl'))
@@ -307,7 +312,7 @@ describe("API: set highlight", function()
       exec_capture('highlight Test_hl3'))
   end)
 
-  it ("can modify a highlight in the global namespace", function()
+  it("can modify a highlight in the global namespace", function()
     meths.set_hl(0, 'Test_hl3', { bg = 'red', fg = 'blue'})
     eq('Test_hl3       xxx guifg=Blue guibg=Red',
       exec_capture('highlight Test_hl3'))
@@ -328,17 +333,17 @@ describe("API: set highlight", function()
     eq('Test_hl3       xxx ctermbg=9',
       exec_capture('highlight Test_hl3'))
 
-    eq("'redd' is not a valid color",
+    eq("Invalid highlight color: 'redd'",
       pcall_err(meths.set_hl, 0, 'Test_hl3', {fg='redd'}))
 
-    eq("'bleu' is not a valid color",
+    eq("Invalid highlight color: 'bleu'",
       pcall_err(meths.set_hl, 0, 'Test_hl3', {ctermfg='bleu'}))
 
     meths.set_hl(0, 'Test_hl3', {fg='#FF00FF'})
     eq('Test_hl3       xxx guifg=#ff00ff',
       exec_capture('highlight Test_hl3'))
 
-    eq("'#FF00FF' is not a valid color",
+    eq("Invalid highlight color: '#FF00FF'",
       pcall_err(meths.set_hl, 0, 'Test_hl3', {ctermfg='#FF00FF'}))
 
     for _, fg_val in ipairs{ nil, 'NONE', 'nOnE', '', -1 } do
@@ -353,14 +358,298 @@ describe("API: set highlight", function()
 
   end)
 
-  it ("correctly sets 'Normal' internal properties", function()
+  it("correctly sets 'Normal' internal properties", function()
     -- Normal has some special handling internally. #18024
     meths.set_hl(0, 'Normal', {fg='#000083', bg='#0000F3'})
     eq({foreground = 131, background = 243}, nvim("get_hl_by_name", 'Normal', true))
   end)
 
   it('does not segfault on invalid group name #20009', function()
-    eq('Invalid highlight name: foo bar', pcall_err(meths.set_hl, 0, 'foo bar', {bold = true}))
+    eq("Invalid highlight name: 'foo bar'", pcall_err(meths.set_hl, 0, 'foo bar', {bold = true}))
     assert_alive()
   end)
 end)
+
+describe('API: get highlight', function()
+  local highlight_color = {
+    fg = tonumber('0xff0000'),
+    bg = tonumber('0x0032aa'),
+    ctermfg = 8,
+    ctermbg = 15,
+  }
+  local highlight1 = {
+    bg = highlight_color.bg,
+    fg = highlight_color.fg,
+    bold = true, italic = true,
+    cterm = {bold = true, italic = true},
+  }
+  local highlight2 = {
+    ctermbg = highlight_color.ctermbg,
+    ctermfg = highlight_color.ctermfg,
+    underline = true, reverse = true,
+    cterm = {underline = true, reverse = true},
+  }
+  local highlight3_config = {
+    bg = highlight_color.bg,
+    fg = highlight_color.fg,
+    ctermbg = highlight_color.ctermbg,
+    ctermfg = highlight_color.ctermfg,
+    bold = true,
+    italic = true,
+    reverse = true,
+    underdashed = true,
+    strikethrough = true,
+    altfont = true,
+    cterm = {
+      italic = true,
+      reverse = true,
+      strikethrough = true,
+      altfont = true,
+      nocombine = true,
+    },
+  }
+  local highlight3_result = {
+    bg = highlight_color.bg,
+    fg = highlight_color.fg,
+    ctermbg = highlight_color.ctermbg,
+    ctermfg = highlight_color.ctermfg,
+    bold = true, italic = true, reverse = true, underdashed = true, strikethrough = true, altfont = true,
+    cterm = {italic = true, nocombine = true, reverse = true, strikethrough = true, altfont = true}
+  }
+
+  local function get_ns()
+    -- Test namespace filtering behavior
+    local ns2 = meths.create_namespace('Another_namespace')
+    meths.set_hl(ns2, 'Test_hl', { ctermfg = 23 })
+    meths.set_hl(ns2, 'Test_another_hl', { link = 'Test_hl' })
+    meths.set_hl(ns2, 'Test_hl_link', { link = 'Test_another_hl' })
+    meths.set_hl(ns2, 'Test_another_hl_link', { link = 'Test_hl_link' })
+
+    local ns = meths.create_namespace('Test_set_hl')
+    meths.set_hl_ns(ns)
+
+    return ns
+  end
+
+  before_each(clear)
+
+  it('validation', function()
+    eq("Invalid 'name': expected String, got Integer",
+       pcall_err(meths.get_hl, 0, { name = 177 }))
+    eq('Highlight id out of bounds', pcall_err(meths.get_hl, 0, { name = 'Test set hl' }))
+  end)
+
+  it('nvim_get_hl with create flag', function()
+    eq({}, nvim("get_hl", 0, {name = 'Foo', create = false}))
+    eq(0, funcs.hlexists('Foo'))
+    meths.get_hl(0, {name = 'Bar', create = true})
+    eq(1, funcs.hlexists('Bar'))
+    meths.get_hl(0, {name = 'FooBar'})
+    eq(1, funcs.hlexists('FooBar'))
+  end)
+
+  it('can get all highlights in current namespace', function()
+    local ns = get_ns()
+    meths.set_hl(ns, 'Test_hl', { bg = '#B4BEFE' })
+    meths.set_hl(ns, 'Test_hl_link', { link = 'Test_hl' })
+    eq({
+      Test_hl = {
+        bg = 11845374
+      },
+      Test_hl_link = {
+        link = 'Test_hl'
+      }
+    }, meths.get_hl(ns, {}))
+  end)
+
+  it('can get gui highlight', function()
+    local ns = get_ns()
+    meths.set_hl(ns, 'Test_hl', highlight1)
+    eq(highlight1, meths.get_hl(ns, { name = 'Test_hl' }))
+  end)
+
+  it('can get cterm highlight', function()
+    local ns = get_ns()
+    meths.set_hl(ns, 'Test_hl', highlight2)
+    eq(highlight2, meths.get_hl(ns, { name = 'Test_hl' }))
+  end)
+
+  it('can get empty cterm attr', function()
+    local ns = get_ns()
+    meths.set_hl(ns, 'Test_hl', { cterm = {} })
+    eq({}, meths.get_hl(ns, { name = 'Test_hl' }))
+  end)
+
+  it('cterm attr defaults to gui attr', function()
+    local ns = get_ns()
+    meths.set_hl(ns, 'Test_hl', highlight1)
+    eq(highlight1, meths.get_hl(ns, { name = 'Test_hl' }))
+  end)
+
+  it('can overwrite attr for cterm', function()
+    local ns = get_ns()
+    meths.set_hl(ns, 'Test_hl', highlight3_config)
+    eq(highlight3_result, meths.get_hl(ns, { name = 'Test_hl' }))
+  end)
+
+  it('only allows one underline attribute #22371', function()
+    local ns = get_ns()
+    meths.set_hl(ns, 'Test_hl', {
+      underdouble = true,
+      underdotted = true,
+      cterm = {
+        underline = true,
+        undercurl = true,
+      },
+    })
+    eq({ underdotted = true, cterm = { undercurl = true} },
+       meths.get_hl(ns, { name = 'Test_hl' }))
+  end)
+
+  it('can get a highlight in the global namespace', function()
+    meths.set_hl(0, 'Test_hl', highlight2)
+    eq(highlight2, meths.get_hl(0, { name = 'Test_hl' }))
+
+    meths.set_hl(0, 'Test_hl', { background = highlight_color.bg })
+    eq({
+      bg = 12970,
+    }, meths.get_hl(0, { name = 'Test_hl' }))
+
+    meths.set_hl(0, 'Test_hl2', highlight3_config)
+    eq(highlight3_result, meths.get_hl(0, { name = 'Test_hl2' }))
+
+    -- Colors are stored with the name they are defined, but
+    -- with canonical casing
+    meths.set_hl(0, 'Test_hl3', { bg = 'reD', fg = 'bLue' })
+    eq({
+      bg = 16711680,
+      fg = 255,
+    }, meths.get_hl(0, { name = 'Test_hl3' }))
+  end)
+
+  it('nvim_get_hl by id', function()
+    local hl_id = meths.get_hl_id_by_name('NewHighlight')
+
+    command(
+      'hi NewHighlight cterm=underline ctermbg=green guifg=red guibg=yellow guisp=blue gui=bold'
+    )
+    eq({ fg = 16711680, bg = 16776960, sp = 255, bold = true,
+         ctermbg = 10, cterm = { underline = true },
+    }, meths.get_hl(0, { id = hl_id }))
+
+    -- Test 0 argument
+    eq('Highlight id out of bounds', pcall_err(meths.get_hl, 0, { id = 0 }))
+
+    eq(
+      "Invalid 'id': expected Integer, got String",
+      pcall_err(meths.get_hl, 0, { id = 'Test_set_hl' })
+    )
+
+    -- Test all highlight properties.
+    command('hi NewHighlight gui=underline,bold,italic,reverse,strikethrough,altfont,nocombine')
+    eq({ fg = 16711680, bg = 16776960, sp = 255,
+         altfont = true, bold = true, italic = true, nocombine = true, reverse = true, strikethrough = true, underline = true,
+         ctermbg = 10, cterm = {underline = true},
+    }, meths.get_hl(0, { id = hl_id }))
+
+    -- Test undercurl
+    command('hi NewHighlight gui=undercurl')
+    eq({ fg = 16711680, bg = 16776960, sp = 255, undercurl = true,
+         ctermbg = 10,
+         cterm = {underline = true},
+    }, meths.get_hl(0, { id = hl_id }))
+  end)
+
+  it('can correctly detect links', function()
+    command('hi String guifg=#a6e3a1')
+    command('hi link @string string')
+    command('hi link @string.cpp @string')
+    eq({ fg = 10937249 }, meths.get_hl(0, { name = 'String' }))
+    eq({ link = 'String' }, meths.get_hl(0, { name = '@string' }))
+    eq({ fg = 10937249 }, meths.get_hl(0, { name = '@string.cpp', link = false }))
+  end)
+
+  it('can get all attributes for a linked group', function()
+    command('hi Bar guifg=red')
+    command('hi Foo guifg=#00ff00 gui=bold,underline')
+    command('hi! link Foo Bar')
+    eq({ link = 'Bar', fg = tonumber('00ff00', 16), bold = true, underline = true }, meths.get_hl(0, { name = 'Foo', link = true }))
+  end)
+
+  it('can set link as well as other attributes', function()
+    command('hi Bar guifg=red')
+    local hl = { link = 'Bar', fg = tonumber('00ff00', 16), bold = true, cterm = { bold = true } }
+    meths.set_hl(0, 'Foo', hl)
+    eq(hl, meths.get_hl(0, { name = 'Foo', link = true }))
+  end)
+
+  it("doesn't contain unset groups", function()
+    local id = meths.get_hl_id_by_name "@foobar.hubbabubba"
+    ok(id > 0)
+
+    local data = meths.get_hl(0, {})
+    eq(nil, data["@foobar.hubbabubba"])
+    eq(nil, data["@foobar"])
+
+    command 'hi @foobar.hubbabubba gui=bold'
+    data = meths.get_hl(0, {})
+    eq({bold = true}, data["@foobar.hubbabubba"])
+    eq(nil, data["@foobar"])
+
+    -- @foobar.hubbabubba was explicitly cleared and thus shows up
+    -- but @foobar was never touched, and thus doesn't
+    command 'hi clear @foobar.hubbabubba'
+    data = meths.get_hl(0, {})
+    eq({}, data["@foobar.hubbabubba"])
+    eq(nil, data["@foobar"])
+  end)
+
+  it('should return default flag', function()
+    meths.set_hl(0, 'Tried', { fg = "#00ff00", default = true })
+    eq({ fg = tonumber('00ff00', 16), default = true }, meths.get_hl(0, { name = 'Tried' }))
+  end)
+
+  it('should not output empty gui and cterm #23474', function()
+    meths.set_hl(0, 'Foo', {default = true})
+    meths.set_hl(0, 'Bar', { default = true, fg = '#ffffff' })
+    meths.set_hl(0, 'FooBar', { default = true, fg = '#ffffff', cterm = {bold = true} })
+    meths.set_hl(0, 'FooBarA', { default = true, fg = '#ffffff', cterm = {bold = true,italic = true}})
+
+    eq('Foo            xxx cleared',
+      exec_capture('highlight Foo'))
+    eq({default = true}, meths.get_hl(0, {name = 'Foo'}))
+    eq('Bar            xxx guifg=#ffffff',
+      exec_capture('highlight Bar'))
+    eq('FooBar         xxx cterm=bold guifg=#ffffff',
+      exec_capture('highlight FooBar'))
+    eq('FooBarA        xxx cterm=bold,italic guifg=#ffffff',
+      exec_capture('highlight FooBarA'))
+  end)
+
+  it('can override exist highlight group by force #20323', function()
+    local white = tonumber('ffffff', 16)
+    local green = tonumber('00ff00', 16)
+    meths.set_hl(0, 'Foo', { fg=white })
+    meths.set_hl(0, 'Foo', { fg=green, force = true })
+    eq({ fg = green },meths.get_hl(0, {name = 'Foo'}))
+    meths.set_hl(0, 'Bar', {link = 'Comment', default = true})
+    meths.set_hl(0, 'Bar', {link = 'Foo',default = true, force = true})
+    eq({link ='Foo', default = true}, meths.get_hl(0, {name = 'Bar'}))
+  end)
+end)
+
+describe('API: set/get highlight namespace', function()
+  it('set/get highlight namespace', function()
+    eq(0, meths.get_hl_ns({}))
+    local ns = meths.create_namespace('')
+    meths.set_hl_ns(ns)
+    eq(ns, meths.get_hl_ns({}))
+  end)
+
+  it('set/get window highlight namespace', function()
+    eq(-1, meths.get_hl_ns({winid = 0}))
+    local ns = meths.create_namespace('')
+    meths.win_set_hl_ns(0, ns)
+    eq(ns, meths.get_hl_ns({winid = 0}))
+  end)
+end)
diff --git a/test/functional/api/keymap_spec.lua b/test/functional/api/keymap_spec.lua
index 5be4425162..434f117956 100644
--- a/test/functional/api/keymap_spec.lua
+++ b/test/functional/api/keymap_spec.lua
@@ -19,6 +19,20 @@ local sleep = helpers.sleep
 local sid_api_client = -9
 local sid_lua = -8
 
+local mode_bits_map = {
+  ['n'] = 0x01,
+  ['x'] = 0x02,
+  ['o'] = 0x04,
+  ['c'] = 0x08,
+  ['i'] = 0x10,
+  ['l'] = 0x20,
+  ['s'] = 0x40,
+  ['t'] = 0x80,
+  [' '] = 0x47,
+  ['v'] = 0x42,
+  ['!'] = 0x18,
+}
+
 describe('nvim_get_keymap', function()
   before_each(clear)
 
@@ -32,9 +46,12 @@ describe('nvim_get_keymap', function()
     rhs='bar',
     expr=0,
     sid=0,
+    scriptversion=1,
     buffer=0,
     nowait=0,
     mode='n',
+    mode_bits=0x01,
+    abbr=0,
     noremap=1,
     lnum=0,
   }
@@ -81,6 +98,7 @@ describe('nvim_get_keymap', function()
     -- The table will be the same except for the mode
     local insert_table = shallowcopy(foo_bar_map_table)
     insert_table['mode'] = 'i'
+    insert_table['mode_bits'] = 0x10
 
     eq({insert_table}, meths.get_keymap('i'))
   end)
@@ -258,8 +276,10 @@ describe('nvim_get_keymap', function()
       silent=0,
       expr=0,
       sid=0,
+      scriptversion=1,
       buffer=0,
       nowait=0,
+      abbr=0,
       noremap=1,
       lnum=0,
     }
@@ -268,6 +288,7 @@ describe('nvim_get_keymap', function()
       ret.lhs = lhs
       ret.rhs = rhs
       ret.mode = mode
+      ret.mode_bits = mode_bits_map[mode]
       return ret
     end
 
@@ -323,10 +344,13 @@ describe('nvim_get_keymap', function()
       lhsraw='|   |',
       rhs='|    |',
       mode='n',
+      mode_bits=0x01,
+      abbr=0,
       script=0,
       silent=0,
       expr=0,
       sid=0,
+      scriptversion=1,
       buffer=0,
       nowait=0,
       noremap=1,
@@ -365,15 +389,18 @@ describe('nvim_get_keymap', function()
       silent=0,
       expr=0,
       sid=sid_lua,
+      scriptversion=1,
       buffer=0,
       nowait=0,
       mode='n',
+      mode_bits=0x01,
+      abbr=0,
       noremap=0,
       lnum=0,
     }, mapargs[1])
   end)
 
-  it ('can handle map descriptions', function()
+  it('can handle map descriptions', function()
     meths.set_keymap('n', 'lhs', 'rhs', {desc="map description"})
     eq({
       lhs='lhs',
@@ -383,9 +410,12 @@ describe('nvim_get_keymap', function()
       silent=0,
       expr=0,
       sid=sid_api_client,
+      scriptversion=1,
       buffer=0,
       nowait=0,
       mode='n',
+      mode_bits=0x01,
+      abbr=0,
       noremap=0,
       lnum=0,
       desc='map description'
@@ -400,6 +430,9 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
   -- maparg(), which does not accept "!" (though it returns "!" in its output
   -- if getting a mapping set with |:map!|).
   local function normalize_mapmode(mode, generate_expected)
+    if mode:sub(-1) == 'a' then
+      mode = mode:sub(1, -2)
+    end
     if not generate_expected and mode == '!' then
       -- Cannot retrieve mapmode-ic mappings with "!", but can with "i" or "c".
       mode = 'i'
@@ -417,7 +450,10 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
     end
 
     local to_return = {}
-    to_return.mode = normalize_mapmode(mode, true)
+    local expected_mode = normalize_mapmode(mode, true)
+    to_return.mode = expected_mode
+    to_return.mode_bits = mode_bits_map[expected_mode]
+    to_return.abbr = mode:sub(-1) == 'a' and 1 or 0
     to_return.noremap = not opts.noremap and 0 or 1
     to_return.lhs = lhs
     to_return.rhs = rhs
@@ -426,6 +462,7 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
     to_return.nowait = not opts.nowait and 0 or 1
     to_return.expr = not opts.expr and 0 or 1
     to_return.sid = not opts.sid and sid_api_client or opts.sid
+    to_return.scriptversion = 1
     to_return.buffer = not opts.buffer and 0 or opts.buffer
     to_return.lnum = not opts.lnum and 0 or opts.lnum
     to_return.desc = opts.desc
@@ -435,7 +472,7 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
 
   -- Gets a maparg() dict from Nvim, if one exists.
   local function get_mapargs(mode, lhs)
-    local mapargs = funcs.maparg(lhs, normalize_mapmode(mode), false, true)
+    local mapargs = funcs.maparg(lhs, normalize_mapmode(mode), mode:sub(-1) == 'a', true)
     -- drop "lhsraw" and "lhsrawalt" which are hard to check
     mapargs.lhsraw = nil
     mapargs.lhsrawalt = nil
@@ -450,7 +487,7 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
   end)
 
   it('error if LHS longer than MAXMAPLEN', function()
-    -- assume MAXMAPLEN of 50 chars, as declared in vim.h
+    -- assume MAXMAPLEN of 50 chars, as declared in mapping_defs.h
     local MAXMAPLEN = 50
     local lhs = ''
     for i=1,MAXMAPLEN do
@@ -484,35 +521,33 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
        get_mapargs('', 'lhs'))
   end)
 
-  it('throws errors when given too-long mode shortnames', function()
-    eq('Shortname is too long: map',
-      pcall_err(meths.set_keymap, 'map', 'lhs', 'rhs', {}))
-
-    eq('Shortname is too long: vmap',
-      pcall_err(meths.set_keymap, 'vmap', 'lhs', 'rhs', {}))
-
-    eq('Shortname is too long: xnoremap',
-      pcall_err(meths.set_keymap, 'xnoremap', 'lhs', 'rhs', {}))
-
-    eq('Shortname is too long: map', pcall_err(meths.del_keymap, 'map', 'lhs'))
-    eq('Shortname is too long: vmap', pcall_err(meths.del_keymap, 'vmap', 'lhs'))
-    eq('Shortname is too long: xnoremap', pcall_err(meths.del_keymap, 'xnoremap', 'lhs'))
-  end)
-
   it('error on invalid mode shortname', function()
-    eq('Invalid mode shortname: " "',
-      pcall_err(meths.set_keymap, ' ', 'lhs', 'rhs', {}))
-    eq('Invalid mode shortname: "m"',
-      pcall_err(meths.set_keymap, 'm', 'lhs', 'rhs', {}))
-    eq('Invalid mode shortname: "?"',
-      pcall_err(meths.set_keymap, '?', 'lhs', 'rhs', {}))
-    eq('Invalid mode shortname: "y"',
-      pcall_err(meths.set_keymap, 'y', 'lhs', 'rhs', {}))
-    eq('Invalid mode shortname: "p"',
-      pcall_err(meths.set_keymap, 'p', 'lhs', 'rhs', {}))
+    eq('Invalid mode shortname: " "', pcall_err(meths.set_keymap, ' ', 'lhs', 'rhs', {}))
+    eq('Invalid mode shortname: "m"', pcall_err(meths.set_keymap, 'm', 'lhs', 'rhs', {}))
+    eq('Invalid mode shortname: "?"', pcall_err(meths.set_keymap, '?', 'lhs', 'rhs', {}))
+    eq('Invalid mode shortname: "y"', pcall_err(meths.set_keymap, 'y', 'lhs', 'rhs', {}))
+    eq('Invalid mode shortname: "p"', pcall_err(meths.set_keymap, 'p', 'lhs', 'rhs', {}))
+    eq('Invalid mode shortname: "a"', pcall_err(meths.set_keymap, 'a', 'lhs', 'rhs', {}))
+    eq('Invalid mode shortname: "oa"', pcall_err(meths.set_keymap, 'oa', 'lhs', 'rhs', {}))
+    eq('Invalid mode shortname: "!o"', pcall_err(meths.set_keymap, '!o', 'lhs', 'rhs', {}))
+    eq('Invalid mode shortname: "!i"', pcall_err(meths.set_keymap, '!i', 'lhs', 'rhs', {}))
+    eq('Invalid mode shortname: "!!"', pcall_err(meths.set_keymap, '!!', 'lhs', 'rhs', {}))
+    eq('Invalid mode shortname: "map"', pcall_err(meths.set_keymap, 'map', 'lhs', 'rhs', {}))
+    eq('Invalid mode shortname: "vmap"', pcall_err(meths.set_keymap, 'vmap', 'lhs', 'rhs', {}))
+    eq('Invalid mode shortname: "xnoremap"', pcall_err(meths.set_keymap, 'xnoremap', 'lhs', 'rhs', {}))
+    eq('Invalid mode shortname: " "', pcall_err(meths.del_keymap, ' ', 'lhs'))
+    eq('Invalid mode shortname: "m"', pcall_err(meths.del_keymap, 'm', 'lhs'))
     eq('Invalid mode shortname: "?"', pcall_err(meths.del_keymap, '?', 'lhs'))
     eq('Invalid mode shortname: "y"', pcall_err(meths.del_keymap, 'y', 'lhs'))
     eq('Invalid mode shortname: "p"', pcall_err(meths.del_keymap, 'p', 'lhs'))
+    eq('Invalid mode shortname: "a"', pcall_err(meths.del_keymap, 'a', 'lhs'))
+    eq('Invalid mode shortname: "oa"', pcall_err(meths.del_keymap, 'oa', 'lhs'))
+    eq('Invalid mode shortname: "!o"', pcall_err(meths.del_keymap, '!o', 'lhs'))
+    eq('Invalid mode shortname: "!i"', pcall_err(meths.del_keymap, '!i', 'lhs'))
+    eq('Invalid mode shortname: "!!"', pcall_err(meths.del_keymap, '!!', 'lhs'))
+    eq('Invalid mode shortname: "map"', pcall_err(meths.del_keymap, 'map', 'lhs'))
+    eq('Invalid mode shortname: "vmap"', pcall_err(meths.del_keymap, 'vmap', 'lhs'))
+    eq('Invalid mode shortname: "xnoremap"', pcall_err(meths.del_keymap, 'xnoremap', 'lhs'))
   end)
 
   it('error on invalid optnames', function()
@@ -681,13 +716,13 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
   end)
 
   it('can set <expr> mappings whose RHS change dynamically', function()
-    meths.exec([[
+    exec([[
         function! FlipFlop() abort
           if !exists('g:flip') | let g:flip = 0 | endif
           let g:flip = !g:flip
           return g:flip
         endfunction
-        ]], true)
+        ]])
     eq(1, meths.call_function('FlipFlop', {}))
     eq(0, meths.call_function('FlipFlop', {}))
     eq(1, meths.call_function('FlipFlop', {}))
@@ -744,7 +779,7 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
   end)
 
   -- Perform exhaustive tests of basic functionality
-  local mapmodes = {'n', 'v', 'x', 's', 'o', '!', 'i', 'l', 'c', 't', ''}
+  local mapmodes = {'n', 'v', 'x', 's', 'o', '!', 'i', 'l', 'c', 't', '', 'ia', 'ca', '!a'}
   for _, mapmode in ipairs(mapmodes) do
     it('can set/unset normal mappings in mapmode '..mapmode, function()
       meths.set_keymap(mapmode, 'lhs', 'rhs', {})
@@ -773,11 +808,9 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
   -- remove some map arguments that are harder to test, or were already tested
   optnames = {'nowait', 'silent', 'expr', 'noremap'}
   for _, mapmode in ipairs(mapmodes) do
-    local printable_mode = normalize_mapmode(mapmode)
-
     -- Test with single mappings
     for _, maparg in ipairs(optnames) do
-      it('can set/unset '..printable_mode..'-mappings with maparg: '..maparg,
+      it('can set/unset '..mapmode..'-mappings with maparg: '..maparg,
           function()
         meths.set_keymap(mapmode, 'lhs', 'rhs', {[maparg] = true})
         eq(generate_mapargs(mapmode, 'lhs', 'rhs', {[maparg] = true}),
@@ -785,7 +818,7 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
         meths.del_keymap(mapmode, 'lhs')
         eq({}, get_mapargs(mapmode, 'lhs'))
       end)
-      it ('can set/unset '..printable_mode..'-mode mappings with maparg '..
+      it ('can set/unset '..mapmode..'-mode mappings with maparg '..
           maparg..', whose value is false', function()
         meths.set_keymap(mapmode, 'lhs', 'rhs', {[maparg] = false})
         eq(generate_mapargs(mapmode, 'lhs', 'rhs'),
@@ -798,7 +831,7 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
     -- Test with triplets of mappings, one of which is false
     for i = 1, (#optnames - 2) do
       local opt1, opt2, opt3 = optnames[i], optnames[i + 1], optnames[i + 2]
-      it('can set/unset '..printable_mode..'-mode mappings with mapargs '..
+      it('can set/unset '..mapmode..'-mode mappings with mapargs '..
           opt1..', '..opt2..', '..opt3, function()
         local opts = {[opt1] = true, [opt2] = false, [opt3] = true}
         meths.set_keymap(mapmode, 'lhs', 'rhs', opts)
@@ -813,33 +846,36 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
   it('can make lua mappings', function()
     eq(0, exec_lua [[
       GlobalCount = 0
-      vim.api.nvim_set_keymap ('n', 'asdf', '', {callback = function() GlobalCount = GlobalCount + 1 end })
+      vim.api.nvim_set_keymap('n', 'asdf', '', {callback = function() GlobalCount = GlobalCount + 1 end })
       return GlobalCount
     ]])
 
     feed('asdf\n')
 
     eq(1, exec_lua[[return GlobalCount]])
-
   end)
 
-  it (':map command shows lua mapping correctly', function()
+  it(':map command shows lua mapping correctly', function()
     exec_lua [[
-      vim.api.nvim_set_keymap ('n', 'asdf', '', {callback = function() print('jkl;') end })
+      vim.api.nvim_set_keymap('n', 'asdf', '', {callback = function() print('jkl;') end })
     ]]
-    assert.truthy(string.match(exec_lua[[return vim.api.nvim_exec(':nmap asdf', true)]],
-                  "^\nn  asdf          <Lua %d+>"))
+    assert.truthy(
+      string.match(
+        exec_lua[[return vim.api.nvim_exec2(':nmap asdf', { output = true }).output]],
+        "^\nn  asdf          <Lua %d+>"
+      )
+    )
   end)
 
-  it ('mapcheck() returns lua mapping correctly', function()
+  it('mapcheck() returns lua mapping correctly', function()
     exec_lua [[
-      vim.api.nvim_set_keymap ('n', 'asdf', '', {callback = function() print('jkl;') end })
+      vim.api.nvim_set_keymap('n', 'asdf', '', {callback = function() print('jkl;') end })
     ]]
     assert.truthy(string.match(funcs.mapcheck('asdf', 'n'),
                   "^<Lua %d+>"))
   end)
 
-  it ('maparg() returns lua mapping correctly', function()
+  it('maparg() returns lua mapping correctly', function()
     eq(0, exec_lua([[
       GlobalCount = 0
       vim.api.nvim_set_keymap('n', 'asdf', '', {callback = function() GlobalCount = GlobalCount + 1 end })
@@ -867,7 +903,7 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
 
   it('can make lua expr mappings replacing keycodes', function()
     exec_lua [[
-      vim.api.nvim_set_keymap ('n', 'aa', '', {callback = function() return '<Insert>π<C-V><M-π>foo<lt><Esc>' end, expr = true, replace_keycodes = true })
+      vim.api.nvim_set_keymap('n', 'aa', '', {callback = function() return '<Insert>π<C-V><M-π>foo<lt><Esc>' end, expr = true, replace_keycodes = true })
     ]]
 
     feed('aa')
@@ -877,7 +913,7 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
 
   it('can make lua expr mappings without replacing keycodes', function()
     exec_lua [[
-      vim.api.nvim_set_keymap ('i', 'aa', '', {callback = function() return '<space>' end, expr = true })
+      vim.api.nvim_set_keymap('i', 'aa', '', {callback = function() return '<space>' end, expr = true })
     ]]
 
     feed('iaa<esc>')
@@ -887,7 +923,7 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
 
   it('lua expr mapping returning nil is equivalent to returning an empty string', function()
     exec_lua [[
-      vim.api.nvim_set_keymap ('i', 'aa', '', {callback = function() return nil end, expr = true })
+      vim.api.nvim_set_keymap('i', 'aa', '', {callback = function() return nil end, expr = true })
     ]]
 
     feed('iaa<esc>')
@@ -898,17 +934,29 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
   it('does not reset pum in lua mapping', function()
     eq(0, exec_lua [[
       VisibleCount = 0
-      vim.api.nvim_set_keymap ('i', '<F2>', '', {callback = function() VisibleCount = VisibleCount + vim.fn.pumvisible() end})
+      vim.api.nvim_set_keymap('i', '<F2>', '', {callback = function() VisibleCount = VisibleCount + vim.fn.pumvisible() end})
       return VisibleCount
     ]])
     feed('i<C-X><C-V><F2><F2><esc>')
     eq(2, exec_lua[[return VisibleCount]])
   end)
 
+  it('redo of lua mappings in op-pending mode work', function()
+    eq(0, exec_lua [[
+      OpCount = 0
+      vim.api.nvim_set_keymap('o', '<F2>', '', {callback = function() OpCount = OpCount + 1 end})
+      return OpCount
+    ]])
+    feed('d<F2>')
+    eq(1, exec_lua[[return OpCount]])
+    feed('.')
+    eq(2, exec_lua[[return OpCount]])
+  end)
+
   it('can overwrite lua mappings', function()
     eq(0, exec_lua [[
       GlobalCount = 0
-      vim.api.nvim_set_keymap ('n', 'asdf', '', {callback = function() GlobalCount = GlobalCount + 1 end })
+      vim.api.nvim_set_keymap('n', 'asdf', '', {callback = function() GlobalCount = GlobalCount + 1 end })
       return GlobalCount
     ]])
 
@@ -917,7 +965,7 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
     eq(1, exec_lua[[return GlobalCount]])
 
     exec_lua [[
-      vim.api.nvim_set_keymap ('n', 'asdf', '', {callback = function() GlobalCount = GlobalCount - 1 end })
+      vim.api.nvim_set_keymap('n', 'asdf', '', {callback = function() GlobalCount = GlobalCount - 1 end })
     ]]
 
     feed('asdf\n')
@@ -928,7 +976,7 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
   it('can unmap lua mappings', function()
     eq(0, exec_lua [[
       GlobalCount = 0
-      vim.api.nvim_set_keymap ('n', 'asdf', '', {callback = function() GlobalCount = GlobalCount + 1 end })
+      vim.api.nvim_set_keymap('n', 'asdf', '', {callback = function() GlobalCount = GlobalCount + 1 end })
       return GlobalCount
     ]])
 
@@ -973,6 +1021,54 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
     eq("\nn  lhs           rhs\n                 map description",
        helpers.exec_capture("nmap lhs"))
   end)
+
+  it('can define !-mode abbreviations with lua callbacks', function()
+    exec_lua [[
+      GlobalCount = 0
+      vim.api.nvim_set_keymap('!a', 'foo', '', {expr = true, callback = function()
+        GlobalCount = GlobalCount + 1
+        return tostring(GlobalCount)
+      end})
+    ]]
+
+    feed 'iThe foo and the bar and the foo again<esc>'
+    eq('The 1 and the bar and the 2 again', meths.get_current_line())
+
+    feed ':let x = "The foo is the one"<cr>'
+    eq('The 3 is the one', meths.eval'x')
+  end)
+
+  it('can define insert mode abbreviations with lua callbacks', function()
+    exec_lua [[
+      GlobalCount = 0
+      vim.api.nvim_set_keymap('ia', 'foo', '', {expr = true, callback = function()
+        GlobalCount = GlobalCount + 1
+        return tostring(GlobalCount)
+      end})
+    ]]
+
+    feed 'iThe foo and the bar and the foo again<esc>'
+    eq('The 1 and the bar and the 2 again', meths.get_current_line())
+
+    feed ':let x = "The foo is the one"<cr>'
+    eq('The foo is the one', meths.eval'x')
+  end)
+
+  it('can define cmdline mode abbreviations with lua callbacks', function()
+    exec_lua [[
+      GlobalCount = 0
+      vim.api.nvim_set_keymap('ca', 'foo', '', {expr = true, callback = function()
+        GlobalCount = GlobalCount + 1
+        return tostring(GlobalCount)
+      end})
+    ]]
+
+    feed 'iThe foo and the bar and the foo again<esc>'
+    eq('The foo and the bar and the foo again', meths.get_current_line())
+
+    feed ':let x = "The foo is the one"<cr>'
+    eq('The 1 is the one', meths.eval'x')
+  end)
 end)
 
 describe('nvim_buf_set_keymap, nvim_buf_del_keymap', function()
@@ -1074,7 +1170,7 @@ describe('nvim_buf_set_keymap, nvim_buf_del_keymap', function()
   it('can make lua mappings', function()
     eq(0, exec_lua [[
       GlobalCount = 0
-      vim.api.nvim_buf_set_keymap (0, 'n', 'asdf', '', {callback = function() GlobalCount = GlobalCount + 1 end })
+      vim.api.nvim_buf_set_keymap(0, 'n', 'asdf', '', {callback = function() GlobalCount = GlobalCount + 1 end })
       return GlobalCount
     ]])
 
@@ -1085,7 +1181,7 @@ describe('nvim_buf_set_keymap, nvim_buf_del_keymap', function()
 
   it('can make lua expr mappings replacing keycodes', function()
     exec_lua [[
-      vim.api.nvim_buf_set_keymap (0, 'n', 'aa', '', {callback = function() return '<Insert>π<C-V><M-π>foo<lt><Esc>' end, expr = true, replace_keycodes = true })
+      vim.api.nvim_buf_set_keymap(0, 'n', 'aa', '', {callback = function() return '<Insert>π<C-V><M-π>foo<lt><Esc>' end, expr = true, replace_keycodes = true })
     ]]
 
     feed('aa')
@@ -1095,7 +1191,7 @@ describe('nvim_buf_set_keymap, nvim_buf_del_keymap', function()
 
   it('can make lua expr mappings without replacing keycodes', function()
     exec_lua [[
-      vim.api.nvim_buf_set_keymap (0, 'i', 'aa', '', {callback = function() return '<space>' end, expr = true })
+      vim.api.nvim_buf_set_keymap(0, 'i', 'aa', '', {callback = function() return '<space>' end, expr = true })
     ]]
 
     feed('iaa<esc>')
@@ -1107,7 +1203,7 @@ describe('nvim_buf_set_keymap, nvim_buf_del_keymap', function()
   it('can overwrite lua mappings', function()
     eq(0, exec_lua [[
       GlobalCount = 0
-      vim.api.nvim_buf_set_keymap (0, 'n', 'asdf', '', {callback = function() GlobalCount = GlobalCount + 1 end })
+      vim.api.nvim_buf_set_keymap(0, 'n', 'asdf', '', {callback = function() GlobalCount = GlobalCount + 1 end })
       return GlobalCount
     ]])
 
@@ -1116,7 +1212,7 @@ describe('nvim_buf_set_keymap, nvim_buf_del_keymap', function()
     eq(1, exec_lua[[return GlobalCount]])
 
     exec_lua [[
-      vim.api.nvim_buf_set_keymap (0, 'n', 'asdf', '', {callback = function() GlobalCount = GlobalCount - 1 end })
+      vim.api.nvim_buf_set_keymap(0, 'n', 'asdf', '', {callback = function() GlobalCount = GlobalCount - 1 end })
     ]]
 
     feed('asdf\n')
@@ -1127,7 +1223,7 @@ describe('nvim_buf_set_keymap, nvim_buf_del_keymap', function()
   it('can unmap lua mappings', function()
     eq(0, exec_lua [[
       GlobalCount = 0
-      vim.api.nvim_buf_set_keymap (0, 'n', 'asdf', '', {callback = function() GlobalCount = GlobalCount + 1 end })
+      vim.api.nvim_buf_set_keymap(0, 'n', 'asdf', '', {callback = function() GlobalCount = GlobalCount + 1 end })
       return GlobalCount
     ]])
 
diff --git a/test/functional/api/proc_spec.lua b/test/functional/api/proc_spec.lua
index 2028a8fba5..20edea3feb 100644
--- a/test/functional/api/proc_spec.lua
+++ b/test/functional/api/proc_spec.lua
@@ -42,14 +42,14 @@ describe('API', function()
       end)
     end)
 
-    it('validates input', function()
+    it('validation', function()
       local status, rv = pcall(request, "nvim_get_proc_children", -1)
       eq(false, status)
-      eq("Invalid pid: -1", string.match(rv, "Invalid.*"))
+      eq("Invalid 'pid': -1", string.match(rv, "Invalid.*"))
 
       status, rv = pcall(request, "nvim_get_proc_children", 0)
       eq(false, status)
-      eq("Invalid pid: 0", string.match(rv, "Invalid.*"))
+      eq("Invalid 'pid': 0", string.match(rv, "Invalid.*"))
 
       -- Assume PID 99999 does not exist.
       status, rv = pcall(request, "nvim_get_proc_children", 99999)
@@ -68,14 +68,14 @@ describe('API', function()
       neq(pid, pinfo.ppid)
     end)
 
-    it('validates input', function()
+    it('validation', function()
       local status, rv = pcall(request, "nvim_get_proc", -1)
       eq(false, status)
-      eq("Invalid pid: -1", string.match(rv, "Invalid.*"))
+      eq("Invalid 'pid': -1", string.match(rv, "Invalid.*"))
 
       status, rv = pcall(request, "nvim_get_proc", 0)
       eq(false, status)
-      eq("Invalid pid: 0", string.match(rv, "Invalid.*"))
+      eq("Invalid 'pid': 0", string.match(rv, "Invalid.*"))
 
       -- Assume PID 99999 does not exist.
       status, rv = pcall(request, "nvim_get_proc", 99999)
diff --git a/test/functional/api/rpc_fixture.lua b/test/functional/api/rpc_fixture.lua
index 94df751363..c860a6da59 100644
--- a/test/functional/api/rpc_fixture.lua
+++ b/test/functional/api/rpc_fixture.lua
@@ -4,9 +4,8 @@
 package.path = arg[1]
 package.cpath = arg[2]
 
-local mpack = require('mpack')
-local StdioStream = require('nvim.stdio_stream')
-local Session = require('nvim.session')
+local StdioStream = require'test.client.uv_stream'.StdioStream
+local Session = require'test.client.session'
 
 local stdio_stream = StdioStream.open()
 local session = Session.new(stdio_stream)
@@ -19,7 +18,7 @@ local function on_request(method, args)
     return "done!"
   elseif method == "exit" then
     session:stop()
-    return mpack.NIL
+    return vim.NIL
   end
 end
 
diff --git a/test/functional/api/server_notifications_spec.lua b/test/functional/api/server_notifications_spec.lua
index 53642858b2..bc43f6564d 100644
--- a/test/functional/api/server_notifications_spec.lua
+++ b/test/functional/api/server_notifications_spec.lua
@@ -6,9 +6,7 @@ local eq, clear, eval, command, nvim, next_msg =
 local meths = helpers.meths
 local exec_lua = helpers.exec_lua
 local retry = helpers.retry
-local is_ci = helpers.is_ci
 local assert_alive = helpers.assert_alive
-local skip = helpers.skip
 
 local testlog = 'Xtest-server-notify-log'
 
@@ -90,7 +88,6 @@ describe('notify', function()
   end)
 
   it('cancels stale events on channel close', function()
-    skip(is_ci(), 'hangs on CI #14083 #15251')
     local catchan = eval("jobstart(['cat'], {'rpc': v:true})")
     local catpath = eval('exepath("cat")')
     eq({id=catchan, argv={catpath}, stream='job', mode='rpc', client = {}}, exec_lua ([[
diff --git a/test/functional/api/server_requests_spec.lua b/test/functional/api/server_requests_spec.lua
index ceff390dc5..1ad4ad3a02 100644
--- a/test/functional/api/server_requests_spec.lua
+++ b/test/functional/api/server_requests_spec.lua
@@ -199,7 +199,7 @@ describe('server -> client', function()
 
     it('can communicate buffers, tabpages, and windows', function()
       eq({1}, eval("rpcrequest(vim, 'nvim_list_tabpages')"))
-      -- Window IDs start at 1000 (LOWEST_WIN_ID in vim.h)
+      -- Window IDs start at 1000 (LOWEST_WIN_ID in window.h)
       eq({1000}, eval("rpcrequest(vim, 'nvim_list_wins')"))
 
       local buf = eval("rpcrequest(vim, 'nvim_list_bufs')")[1]
@@ -237,7 +237,7 @@ describe('server -> client', function()
         \ }
       ]])
       meths.set_var("args", {
-        helpers.test_lua_prg,
+        nvim_prog, '-ll',
         'test/functional/api/rpc_fixture.lua',
         package.path,
         package.cpath,
@@ -337,6 +337,21 @@ describe('server -> client', function()
       eq('localhost:', string.sub(address,1,10))
       connect_test(server, 'tcp', address)
     end)
+
+    it('does not crash on receiving UI events', function()
+      local server = spawn(nvim_argv)
+      set_session(server)
+      local address = funcs.serverlist()[1]
+      local client = spawn(nvim_argv, false, nil, true)
+      set_session(client)
+
+      local id = funcs.sockconnect('pipe', address, {rpc=true})
+      funcs.rpcrequest(id, 'nvim_ui_attach', 80, 24, {})
+      assert_alive()
+
+      server:close()
+      client:close()
+    end)
   end)
 
   describe('connecting to its own pipe address', function()
diff --git a/test/functional/api/ui_spec.lua b/test/functional/api/ui_spec.lua
index 279cd1856d..6efb6726fe 100644
--- a/test/functional/api/ui_spec.lua
+++ b/test/functional/api/ui_spec.lua
@@ -1,8 +1,11 @@
 local helpers = require('test.functional.helpers')(after_each)
 local Screen = require('test.functional.ui.screen')
 local clear = helpers.clear
+local command = helpers.command
 local eq = helpers.eq
 local eval = helpers.eval
+local exec = helpers.exec
+local feed = helpers.feed
 local meths = helpers.meths
 local request = helpers.request
 local pcall_err = helpers.pcall_err
@@ -11,17 +14,35 @@ describe('nvim_ui_attach()', function()
   before_each(function()
     clear()
   end)
+
   it('handles very large width/height #2180', function()
     local screen = Screen.new(999, 999)
     screen:attach()
     eq(999, eval('&lines'))
     eq(999, eval('&columns'))
   end)
-  it('invalid option returns error', function()
+
+  it('validation', function()
     eq('No such UI option: foo',
       pcall_err(meths.ui_attach, 80, 24, { foo={'foo'} }))
-  end)
-  it('validates channel arg', function()
+
+    eq("Invalid 'ext_linegrid': expected Boolean, got Array",
+      pcall_err(meths.ui_attach, 80, 24, { ext_linegrid={} }))
+    eq("Invalid 'override': expected Boolean, got Array",
+      pcall_err(meths.ui_attach, 80, 24, { override={} }))
+    eq("Invalid 'rgb': expected Boolean, got Array",
+      pcall_err(meths.ui_attach, 80, 24, { rgb={} }))
+    eq("Invalid 'term_name': expected String, got Boolean",
+      pcall_err(meths.ui_attach, 80, 24, { term_name=true }))
+    eq("Invalid 'term_colors': expected Integer, got Boolean",
+      pcall_err(meths.ui_attach, 80, 24, { term_colors=true }))
+    eq("Invalid 'stdin_fd': expected Integer, got String",
+      pcall_err(meths.ui_attach, 80, 24, { stdin_fd='foo' }))
+    eq("Invalid 'stdin_tty': expected Boolean, got String",
+      pcall_err(meths.ui_attach, 80, 24, { stdin_tty='foo' }))
+    eq("Invalid 'stdout_tty': expected Boolean, got String",
+      pcall_err(meths.ui_attach, 80, 24, { stdout_tty='foo' }))
+
     eq('UI not attached to channel: 1',
       pcall_err(request, 'nvim_ui_try_resize', 40, 10))
     eq('UI not attached to channel: 1',
@@ -37,14 +58,13 @@ describe('nvim_ui_attach()', function()
 end)
 
 it('autocmds UIEnter/UILeave', function()
-  clear{
-    args_rm={'--headless'},
-    args={
-      '--cmd', 'let g:evs = []',
-      '--cmd', 'autocmd UIEnter * :call add(g:evs, "UIEnter") | let g:uienter_ev = deepcopy(v:event)',
-      '--cmd', 'autocmd UILeave * :call add(g:evs, "UILeave") | let g:uileave_ev = deepcopy(v:event)',
-      '--cmd', 'autocmd VimEnter * :call add(g:evs, "VimEnter")',
-    }}
+  clear{args_rm={'--headless'}}
+  exec([[
+    let g:evs = []
+    autocmd UIEnter * call add(g:evs, "UIEnter") | let g:uienter_ev = deepcopy(v:event)
+    autocmd UILeave * call add(g:evs, "UILeave") | let g:uileave_ev = deepcopy(v:event)
+    autocmd VimEnter * call add(g:evs, "VimEnter")
+  ]])
   local screen = Screen.new()
   screen:attach()
   eq({chan=1}, eval('g:uienter_ev'))
@@ -56,3 +76,45 @@ it('autocmds UIEnter/UILeave', function()
     'UILeave',
   }, eval('g:evs'))
 end)
+
+it('autocmds VimSuspend/VimResume #22041', function()
+  clear()
+  local screen = Screen.new()
+  screen:attach()
+  exec([[
+    let g:ev = []
+    autocmd VimResume  * :call add(g:ev, 'r')
+    autocmd VimSuspend * :call add(g:ev, 's')
+  ]])
+
+  eq(false, screen.suspended)
+  feed('<C-Z>')
+  screen:expect(function() eq(true, screen.suspended) end)
+  eq({ 's' }, eval('g:ev'))
+  screen.suspended = false
+  feed('<Ignore>')
+  eq({ 's', 'r' }, eval('g:ev'))
+
+  command('suspend')
+  screen:expect(function() eq(true, screen.suspended) end)
+  eq({ 's', 'r', 's' }, eval('g:ev'))
+  screen.suspended = false
+  meths.input_mouse('move', '', '', 0, 0, 0)
+  eq({ 's', 'r', 's', 'r' }, eval('g:ev'))
+
+  feed('<C-Z><C-Z><C-Z>')
+  screen:expect(function() eq(true, screen.suspended) end)
+  meths.ui_set_focus(false)
+  eq({ 's', 'r', 's', 'r', 's' }, eval('g:ev'))
+  screen.suspended = false
+  meths.ui_set_focus(true)
+  eq({ 's', 'r', 's', 'r', 's', 'r' }, eval('g:ev'))
+
+  command('suspend | suspend | suspend')
+  screen:expect(function() eq(true, screen.suspended) end)
+  screen:detach()
+  eq({ 's', 'r', 's', 'r', 's', 'r', 's' }, eval('g:ev'))
+  screen.suspended = false
+  screen:attach()
+  eq({ 's', 'r', 's', 'r', 's', 'r', 's', 'r' }, eval('g:ev'))
+end)
diff --git a/test/functional/api/version_spec.lua b/test/functional/api/version_spec.lua
index 771192e9ab..6d466b0cc1 100644
--- a/test/functional/api/version_spec.lua
+++ b/test/functional/api/version_spec.lua
@@ -34,6 +34,7 @@ describe("api_info()['version']", function()
     local minor   = version['minor']
     local patch   = version['patch']
     local prerelease = version['prerelease']
+    local build   = version['build']
     eq("number", type(major))
     eq("number", type(minor))
     eq("number", type(patch))
@@ -42,6 +43,7 @@ describe("api_info()['version']", function()
     eq(0, funcs.has("nvim-"..major.."."..minor.."."..(patch + 1)))
     eq(0, funcs.has("nvim-"..major.."."..(minor + 1).."."..patch))
     eq(0, funcs.has("nvim-"..(major + 1).."."..minor.."."..patch))
+    assert(build == nil or type(build) == 'string')
   end)
 end)
 
diff --git a/test/functional/api/vim_spec.lua b/test/functional/api/vim_spec.lua
index 8fcdd9620b..8bbadda9b0 100644
--- a/test/functional/api/vim_spec.lua
+++ b/test/functional/api/vim_spec.lua
@@ -1,6 +1,5 @@
 local helpers = require('test.functional.helpers')(after_each)
 local Screen = require('test.functional.ui.screen')
-local lfs = require('lfs')
 local luv = require('luv')
 
 local fmt = string.format
@@ -9,6 +8,7 @@ local NIL = helpers.NIL
 local clear, nvim, eq, neq = helpers.clear, helpers.nvim, helpers.eq, helpers.neq
 local command = helpers.command
 local exec = helpers.exec
+local exec_capture = helpers.exec_capture
 local eval = helpers.eval
 local expect = helpers.expect
 local funcs = helpers.funcs
@@ -28,7 +28,6 @@ local write_file = helpers.write_file
 local exec_lua = helpers.exec_lua
 local exc_exec = helpers.exc_exec
 local insert = helpers.insert
-local expect_exit = helpers.expect_exit
 local skip = helpers.skip
 
 local pcall_err = helpers.pcall_err
@@ -59,7 +58,7 @@ describe('API', function()
 
     -- XXX: This must be the last one, else next one will fail:
     --      "Packer instance already working. Use another Packer ..."
-    matches("can't serialize object$",
+    matches("can't serialize object of type .$",
       pcall_err(request, nil))
   end)
 
@@ -89,132 +88,145 @@ describe('API', function()
     eq({mode='i', blocking=false}, nvim("get_mode"))
   end)
 
-  describe('nvim_exec', function()
+  describe('nvim_exec2', function()
+    it('always returns table', function()
+      -- In built version this results into `vim.empty_dict()`
+      eq({}, nvim('exec2', 'echo "Hello"', {}))
+      eq({}, nvim('exec2', 'echo "Hello"', { output = false }))
+      eq({ output = 'Hello' }, nvim('exec2', 'echo "Hello"', { output = true }))
+    end)
+
+    it('default options', function()
+      -- Should be equivalent to { output = false }
+      nvim('exec2', "let x0 = 'a'", {})
+      eq('a', nvim('get_var', 'x0'))
+    end)
+
     it('one-line input', function()
-      nvim('exec', "let x1 = 'a'", false)
+      nvim('exec2', "let x1 = 'a'", { output = false })
       eq('a', nvim('get_var', 'x1'))
     end)
 
     it(':verbose set {option}?', function()
-      nvim('exec', 'set nowrap', false)
-      eq('nowrap\n\tLast set from anonymous :source',
-        nvim('exec', 'verbose set wrap?', true))
+      nvim('exec2', 'set nowrap', { output = false })
+      eq({ output = 'nowrap\n\tLast set from anonymous :source' },
+        nvim('exec2', 'verbose set wrap?', { output = true }))
 
       -- Using script var to force creation of a script item
-      nvim('exec', [[
+      nvim('exec2', [[
         let s:a = 1
         set nowrap
-      ]], false)
-      eq('nowrap\n\tLast set from anonymous :source (script id 1)',
-        nvim('exec', 'verbose set wrap?', true))
+      ]], { output = false })
+      eq({ output = 'nowrap\n\tLast set from anonymous :source (script id 1)' },
+        nvim('exec2', 'verbose set wrap?', { output = true }))
     end)
 
     it('multiline input', function()
       -- Heredoc + empty lines.
-      nvim('exec', "let x2 = 'a'\n", false)
+      nvim('exec2', "let x2 = 'a'\n", { output = false })
       eq('a', nvim('get_var', 'x2'))
-      nvim('exec','lua <<EOF\n\n\n\ny=3\n\n\nEOF', false)
+      nvim('exec2','lua <<EOF\n\n\n\ny=3\n\n\nEOF', { output = false })
       eq(3, nvim('eval', "luaeval('y')"))
 
-      eq('', nvim('exec', 'lua <<EOF\ny=3\nEOF', false))
+      eq({}, nvim('exec2', 'lua <<EOF\ny=3\nEOF', { output = false }))
       eq(3, nvim('eval', "luaeval('y')"))
 
       -- Multiple statements
-      nvim('exec', 'let x1=1\nlet x2=2\nlet x3=3\n', false)
+      nvim('exec2', 'let x1=1\nlet x2=2\nlet x3=3\n', { output = false })
       eq(1, nvim('eval', 'x1'))
       eq(2, nvim('eval', 'x2'))
       eq(3, nvim('eval', 'x3'))
 
       -- Functions
-      nvim('exec', 'function Foo()\ncall setline(1,["xxx"])\nendfunction', false)
+      nvim('exec2', 'function Foo()\ncall setline(1,["xxx"])\nendfunction', { output = false })
       eq('', nvim('get_current_line'))
-      nvim('exec', 'call Foo()', false)
+      nvim('exec2', 'call Foo()', { output = false })
       eq('xxx', nvim('get_current_line'))
 
       -- Autocmds
-      nvim('exec','autocmd BufAdd * :let x1 = "Hello"', false)
+      nvim('exec2','autocmd BufAdd * :let x1 = "Hello"', { output = false })
       nvim('command', 'new foo')
       eq('Hello', request('nvim_eval', 'g:x1'))
 
       -- Line continuations
-      nvim('exec', [[
+      nvim('exec2', [[
         let abc = #{
           \ a: 1,
          "\ b: 2,
           \ c: 3
-          \ }]], false)
+          \ }]], { output = false })
       eq({a = 1, c = 3}, request('nvim_eval', 'g:abc'))
 
       -- try no spaces before continuations to catch off-by-one error
-      nvim('exec', 'let ab = #{\n\\a: 98,\n"\\ b: 2\n\\}', false)
+      nvim('exec2', 'let ab = #{\n\\a: 98,\n"\\ b: 2\n\\}', { output = false })
       eq({a = 98}, request('nvim_eval', 'g:ab'))
 
       -- Script scope (s:)
-      eq('ahoy! script-scoped varrrrr', nvim('exec', [[
+      eq({ output = 'ahoy! script-scoped varrrrr' }, nvim('exec2', [[
           let s:pirate = 'script-scoped varrrrr'
           function! s:avast_ye_hades(s) abort
             return a:s .. ' ' .. s:pirate
           endfunction
           echo <sid>avast_ye_hades('ahoy!')
-        ]], true))
+        ]], { output = true }))
 
-      eq('ahoy! script-scoped varrrrr', nvim('exec', [[
+      eq({ output = "{'output': 'ahoy! script-scoped varrrrr'}" }, nvim('exec2', [[
           let s:pirate = 'script-scoped varrrrr'
           function! Avast_ye_hades(s) abort
             return a:s .. ' ' .. s:pirate
           endfunction
-          echo nvim_exec('echo Avast_ye_hades(''ahoy!'')', 1)
-        ]], true))
+          echo nvim_exec2('echo Avast_ye_hades(''ahoy!'')', {'output': v:true})
+        ]], { output = true }))
 
       matches('Vim%(echo%):E121: Undefined variable: s:pirate$',
-        pcall_err(request, 'nvim_exec', [[
+        pcall_err(request, 'nvim_exec2', [[
           let s:pirate = 'script-scoped varrrrr'
-          call nvim_exec('echo s:pirate', 1)
-        ]], false))
+          call nvim_exec2('echo s:pirate', {'output': v:true})
+        ]], { output = false }))
 
       -- Script items are created only on script var access
-      eq('1\n0', nvim('exec', [[
+      eq({ output = '1\n0' }, nvim('exec2', [[
           echo expand("<SID>")->empty()
           let s:a = 123
           echo expand("<SID>")->empty()
-        ]], true))
+        ]], { output = true }))
 
-      eq('1\n0', nvim('exec', [[
+      eq({ output = '1\n0' }, nvim('exec2', [[
           echo expand("<SID>")->empty()
           function s:a() abort
           endfunction
           echo expand("<SID>")->empty()
-        ]], true))
+        ]], { output = true }))
     end)
 
     it('non-ASCII input', function()
-      nvim('exec', [=[
+      nvim('exec2', [=[
         new
         exe "normal! i ax \n Ax "
         :%s/ax/--a1234--/g | :%s/Ax/--A1234--/g
-      ]=], false)
+      ]=], { output = false })
       nvim('command', '1')
       eq(' --a1234-- ', nvim('get_current_line'))
       nvim('command', '2')
       eq(' --A1234-- ', nvim('get_current_line'))
 
-      nvim('exec', [[
+      nvim('exec2', [[
         new
         call setline(1,['xxx'])
         call feedkeys('r')
         call feedkeys('ñ', 'xt')
-      ]], false)
+      ]], { output = false })
       eq('ñxx', nvim('get_current_line'))
     end)
 
     it('execution error', function()
-      eq('nvim_exec(): Vim:E492: Not an editor command: bogus_command',
-        pcall_err(request, 'nvim_exec', 'bogus_command', false))
+      eq('nvim_exec2(): Vim:E492: Not an editor command: bogus_command',
+        pcall_err(request, 'nvim_exec2', 'bogus_command', {}))
       eq('', nvim('eval', 'v:errmsg'))  -- v:errmsg was not updated.
       eq('', eval('v:exception'))
 
-      eq('nvim_exec(): Vim(buffer):E86: Buffer 23487 does not exist',
-        pcall_err(request, 'nvim_exec', 'buffer 23487', false))
+      eq('nvim_exec2(): Vim(buffer):E86: Buffer 23487 does not exist',
+        pcall_err(request, 'nvim_exec2', 'buffer 23487', {}))
       eq('', eval('v:errmsg'))  -- v:errmsg was not updated.
       eq('', eval('v:exception'))
     end)
@@ -222,17 +234,17 @@ describe('API', function()
     it('recursion', function()
       local fname = tmpname()
       write_file(fname, 'let x1 = "set from :source file"\n')
-      -- nvim_exec
+      -- nvim_exec2
       --   :source
-      --     nvim_exec
-      request('nvim_exec', [[
+      --     nvim_exec2
+      request('nvim_exec2', [[
         let x2 = substitute('foo','o','X','g')
         let x4 = 'should be overwritten'
-        call nvim_exec("source ]]..fname..[[\nlet x3 = substitute('foo','foo','set by recursive nvim_exec','g')\nlet x5='overwritten'\nlet x4=x5\n", v:false)
-      ]], false)
+        call nvim_exec2("source ]]..fname..[[\nlet x3 = substitute('foo','foo','set by recursive nvim_exec2','g')\nlet x5='overwritten'\nlet x4=x5\n", {'output': v:false})
+      ]], { output = false })
       eq('set from :source file', request('nvim_get_var', 'x1'))
       eq('fXX', request('nvim_get_var', 'x2'))
-      eq('set by recursive nvim_exec', request('nvim_get_var', 'x3'))
+      eq('set by recursive nvim_exec2', request('nvim_get_var', 'x3'))
       eq('overwritten', request('nvim_get_var', 'x4'))
       eq('overwritten', request('nvim_get_var', 'x5'))
       os.remove(fname)
@@ -242,35 +254,35 @@ describe('API', function()
       local fname = tmpname()
       write_file(fname, 'echo "hello"\n')
       local sourcing_fname = tmpname()
-      write_file(sourcing_fname, 'call nvim_exec("source '..fname..'", v:false)\n')
-      meths.exec('set verbose=2', false)
+      write_file(sourcing_fname, 'call nvim_exec2("source '..fname..'", {"output": v:false})\n')
+      meths.exec2('set verbose=2', { output = false })
       local traceback_output = 'line 0: sourcing "'..sourcing_fname..'"\n'..
         'line 0: sourcing "'..fname..'"\n'..
         'hello\n'..
         'finished sourcing '..fname..'\n'..
-        'continuing in nvim_exec() called at '..sourcing_fname..':1\n'..
+        'continuing in nvim_exec2() called at '..sourcing_fname..':1\n'..
         'finished sourcing '..sourcing_fname..'\n'..
-        'continuing in nvim_exec() called at nvim_exec():0'
-      eq(traceback_output,
-        meths.exec('call nvim_exec("source '..sourcing_fname..'", v:false)', true))
+        'continuing in nvim_exec2() called at nvim_exec2():0'
+      eq({ output = traceback_output },
+        meths.exec2('call nvim_exec2("source '..sourcing_fname..'", {"output": v:false})', { output = true }))
       os.remove(fname)
       os.remove(sourcing_fname)
     end)
 
     it('returns output', function()
-      eq('this is spinal tap',
-         nvim('exec', 'lua <<EOF\n\n\nprint("this is spinal tap")\n\n\nEOF', true))
-      eq('', nvim('exec', 'echo', true))
-      eq('foo 42', nvim('exec', 'echo "foo" 42', true))
+      eq({ output = 'this is spinal tap' },
+         nvim('exec2', 'lua <<EOF\n\n\nprint("this is spinal tap")\n\n\nEOF', { output = true }))
+      eq({ output = '' }, nvim('exec2', 'echo', { output = true }))
+      eq({ output = 'foo 42' }, nvim('exec2', 'echo "foo" 42', { output = true }))
     end)
 
-    it('displays messages when output=false', function()
+    it('displays messages when opts.output=false', function()
       local screen = Screen.new(40, 8)
       screen:attach()
       screen:set_default_attr_ids({
         [0] = {bold=true, foreground=Screen.colors.Blue},
       })
-      meths.exec("echo 'hello'", false)
+      meths.exec2("echo 'hello'", { output = false })
       screen:expect{grid=[[
         ^                                        |
         {0:~                                       }|
@@ -289,7 +301,7 @@ describe('API', function()
       screen:set_default_attr_ids({
         [0] = {bold=true, foreground=Screen.colors.Blue},
       })
-      meths.exec("echo 'hello'", true)
+      meths.exec2("echo 'hello'", { output = true })
       screen:expect{grid=[[
         ^                                        |
         {0:~                                       }|
@@ -300,7 +312,7 @@ describe('API', function()
       ]]}
       exec([[
         func Print()
-          call nvim_exec('echo "hello"', v:true)
+          call nvim_exec2('echo "hello"', { 'output': v:true })
         endfunc
       ]])
       feed([[:echon 1 | call Print() | echon 5<CR>]])
@@ -322,8 +334,7 @@ describe('API', function()
       nvim('command', 'edit '..fname)
       nvim('command', 'normal itesting\napi')
       nvim('command', 'w')
-      local f = io.open(fname)
-      ok(f ~= nil)
+      local f = assert(io.open(fname))
       if is_os('win') then
         eq('testing\r\napi\r\n', f:read('*a'))
       else
@@ -333,21 +344,27 @@ describe('API', function()
       os.remove(fname)
     end)
 
-    it('VimL validation error: fails with specific error', function()
+    it('Vimscript validation error: fails with specific error', function()
       local status, rv = pcall(nvim, "command", "bogus_command")
       eq(false, status)                       -- nvim_command() failed.
-      eq("E492:", string.match(rv, "E%d*:"))  -- VimL error was returned.
+      eq("E492:", string.match(rv, "E%d*:"))  -- Vimscript error was returned.
       eq('', nvim('eval', 'v:errmsg'))        -- v:errmsg was not updated.
       eq('', eval('v:exception'))
     end)
 
-    it('VimL execution error: fails with specific error', function()
+    it('Vimscript execution error: fails with specific error', function()
       local status, rv = pcall(nvim, "command", "buffer 23487")
       eq(false, status)                 -- nvim_command() failed.
       eq("E86: Buffer 23487 does not exist", string.match(rv, "E%d*:.*"))
       eq('', eval('v:errmsg'))  -- v:errmsg was not updated.
       eq('', eval('v:exception'))
     end)
+
+    it('gives E493 instead of prompting on backwards range', function()
+      command('split')
+      eq('Vim(windo):E493: Backwards range given: 2,1windo echo',
+         pcall_err(command, '2,1windo echo'))
+    end)
   end)
 
   describe('nvim_command_output', function()
@@ -403,7 +420,7 @@ describe('API', function()
       eq(':!echo foo\r\n\nfoo'..win_lf..'\n', nvim('command_output', [[!echo foo]]))
     end)
 
-    it('VimL validation error: fails with specific error', function()
+    it('Vimscript validation error: fails with specific error', function()
       local status, rv = pcall(nvim, "command_output", "bogus commannnd")
       eq(false, status)                 -- nvim_command_output() failed.
       eq("E492: Not an editor command: bogus commannnd",
@@ -413,7 +430,7 @@ describe('API', function()
       eq({mode='n', blocking=false}, nvim("get_mode"))
     end)
 
-    it('VimL execution error: fails with specific error', function()
+    it('Vimscript execution error: fails with specific error', function()
       local status, rv = pcall(nvim, "command_output", "buffer 42")
       eq(false, status)                 -- nvim_command_output() failed.
       eq("E86: Buffer 42 does not exist", string.match(rv, "E%d*:.*"))
@@ -422,7 +439,7 @@ describe('API', function()
       eq({mode='n', blocking=false}, nvim("get_mode"))
     end)
 
-    it('Does not cause heap buffer overflow with large output', function()
+    it('does not cause heap buffer overflow with large output', function()
       eq(eval('string(range(1000000))'),
          nvim('command_output', 'echo range(1000000)'))
     end)
@@ -444,7 +461,7 @@ describe('API', function()
       eq(2, request("vim_eval", "1+1"))
     end)
 
-    it("VimL error: returns error details, does NOT update v:errmsg", function()
+    it("Vimscript error: returns error details, does NOT update v:errmsg", function()
       eq('Vim:E121: Undefined variable: bogus',
         pcall_err(request, 'nvim_eval', 'bogus expression'))
       eq('', eval('v:errmsg'))  -- v:errmsg was not updated.
@@ -459,7 +476,7 @@ describe('API', function()
       eq('foo', nvim('call_function', 'simplify', {'this/./is//redundant/../../../foo'}))
     end)
 
-    it("VimL validation error: returns specific error, does NOT update v:errmsg", function()
+    it("Vimscript validation error: returns specific error, does NOT update v:errmsg", function()
       eq('Vim:E117: Unknown function: bogus function',
         pcall_err(request, 'nvim_call_function', 'bogus function', {'arg1'}))
       eq('Vim:E119: Not enough arguments for function: atan',
@@ -468,7 +485,7 @@ describe('API', function()
       eq('', eval('v:errmsg'))  -- v:errmsg was not updated.
     end)
 
-    it("VimL error: returns error details, does NOT update v:errmsg", function()
+    it("Vimscript error: returns error details, does NOT update v:errmsg", function()
       eq('Vim:E808: Number or Float required',
         pcall_err(request, 'nvim_call_function', 'atan', {'foo'}))
       eq('Vim:Invalid channel stream "xxx"',
@@ -479,7 +496,7 @@ describe('API', function()
       eq('', eval('v:errmsg'))  -- v:errmsg was not updated.
     end)
 
-    it("VimL exception: returns exception details, does NOT update v:errmsg", function()
+    it("Vimscript exception: returns exception details, does NOT update v:errmsg", function()
       source([[
         function! Foo() abort
           throw 'wtf'
@@ -490,7 +507,7 @@ describe('API', function()
       eq('', eval('v:errmsg'))  -- v:errmsg was not updated.
     end)
 
-    it('validates args', function()
+    it('validation', function()
       local too_many_args = { 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x' }
       source([[
         function! Foo(...) abort
@@ -504,7 +521,7 @@ describe('API', function()
   end)
 
   describe('nvim_call_dict_function', function()
-    it('invokes VimL dict function', function()
+    it('invokes Vimscript dict function', function()
       source([[
         function! F(name) dict
           return self.greeting.', '.a:name.'!'
@@ -532,7 +549,7 @@ describe('API', function()
       eq('@it works@', nvim('call_dict_function', { result = 'it works', G = 'G'}, 'G', {}))
     end)
 
-    it('validates args', function()
+    it('validation', function()
       command('let g:d={"baz":"zub","meep":[]}')
       eq('Not found: bogus',
         pcall_err(request, 'nvim_call_dict_function', 'g:d', 'bogus', {1,2}))
@@ -559,7 +576,6 @@ describe('API', function()
     local start_dir
 
     before_each(function()
-      clear()
       funcs.mkdir("Xtestdir")
       start_dir = funcs.getcwd()
     end)
@@ -575,7 +591,7 @@ describe('API', function()
 
     it('sets previous directory', function()
       meths.set_current_dir("Xtestdir")
-      meths.exec('cd -', false)
+      command('cd -')
       eq(funcs.getcwd(), start_dir)
     end)
   end)
@@ -634,7 +650,7 @@ describe('API', function()
   end)
 
   describe('nvim_input', function()
-    it("VimL error: does NOT fail, updates v:errmsg", function()
+    it("Vimscript error: does NOT fail, updates v:errmsg", function()
       local status, _ = pcall(nvim, "input", ":call bogus_fn()<CR>")
       local v_errnum = string.match(nvim("eval", "v:errmsg"), "E%d*:")
       eq(true, status)        -- nvim_input() did not fail.
@@ -648,10 +664,10 @@ describe('API', function()
   end)
 
   describe('nvim_paste', function()
-    it('validates args', function()
-      eq('Invalid phase: -2',
+    it('validation', function()
+      eq("Invalid 'phase': -2",
         pcall_err(request, 'nvim_paste', 'foo', true, -2))
-      eq('Invalid phase: 4',
+      eq("Invalid 'phase': 4",
         pcall_err(request, 'nvim_paste', 'foo', true, 4))
     end)
     local function run_streamed_paste_tests()
@@ -1032,7 +1048,7 @@ describe('API', function()
         line 3
         ]])
       eq({0,4,1,0}, funcs.getpos('.'))  -- Cursor follows the paste.
-      eq(false, nvim('get_option', 'paste'))
+      eq(false, nvim('get_option_value', 'paste', {}))
       command('%delete _')
       -- Without final "\n".
       nvim('paste', 'line 1\nline 2\nline 3', true, -1)
@@ -1072,7 +1088,7 @@ describe('API', function()
       nvim('paste', 'line 1\r\n\r\rline 2\nline 3\rline 4\r', true, -1)
       expect('line 1\n\n\nline 2\nline 3\nline 4\n')
       eq({0,7,1,0}, funcs.getpos('.'))
-      eq(false, nvim('get_option', 'paste'))
+      eq(false, nvim('get_option_value', 'paste', {}))
     end)
     it('Replace-mode', function()
       -- Within single line
@@ -1154,10 +1170,10 @@ describe('API', function()
   end)
 
   describe('nvim_put', function()
-    it('validates args', function()
-      eq('Invalid lines (expected array of strings)',
+    it('validation', function()
+      eq("Invalid 'line': expected String, got Integer",
         pcall_err(request, 'nvim_put', {42}, 'l', false, false))
-      eq("Invalid type: 'x'",
+      eq("Invalid 'type': 'x'",
         pcall_err(request, 'nvim_put', {'foo'}, 'x', false, false))
     end)
     it("fails if 'nomodifiable'", function()
@@ -1259,9 +1275,9 @@ describe('API', function()
         yyybc line 2
         line 3
         ]])
-      eq("Invalid type: 'bx'",
+      eq("Invalid 'type': 'bx'",
          pcall_err(meths.put, {'xxx', 'yyy'}, 'bx', false, true))
-      eq("Invalid type: 'b3x'",
+      eq("Invalid 'type': 'b3x'",
          pcall_err(meths.put, {'xxx', 'yyy'}, 'b3x', false, true))
     end)
   end)
@@ -1288,6 +1304,11 @@ describe('API', function()
   end)
 
   describe('set/get/del variables', function()
+    it('validation', function()
+      eq('Key not found: bogus', pcall_err(meths.get_var, 'bogus'))
+      eq('Key not found: bogus', pcall_err(meths.del_var, 'bogus'))
+    end)
+
     it('nvim_get_var, nvim_set_var, nvim_del_var', function()
       nvim('set_var', 'lua', {1, 2, {['3'] = 1}})
       eq({1, 2, {['3'] = 1}}, nvim('get_var', 'lua'))
@@ -1329,12 +1350,59 @@ describe('API', function()
     end)
 
     it('nvim_get_vvar, nvim_set_vvar', function()
-      -- Set readonly v: var.
-      eq('Key is read-only: count',
-        pcall_err(request, 'nvim_set_vvar', 'count', 42))
-      -- Set writable v: var.
+      eq('Key is read-only: count', pcall_err(request, 'nvim_set_vvar', 'count', 42))
+      eq('Dictionary is locked', pcall_err(request, 'nvim_set_vvar', 'nosuchvar', 42))
       meths.set_vvar('errmsg', 'set by API')
       eq('set by API', meths.get_vvar('errmsg'))
+      meths.set_vvar('errmsg', 42)
+      eq('42', eval('v:errmsg'))
+      meths.set_vvar('oldfiles', { 'one', 'two' })
+      eq({ 'one', 'two' }, eval('v:oldfiles'))
+      meths.set_vvar('oldfiles', {})
+      eq({}, eval('v:oldfiles'))
+      eq('Setting v:oldfiles to value with wrong type', pcall_err(meths.set_vvar, 'oldfiles', 'a'))
+      eq({}, eval('v:oldfiles'))
+
+      feed('i foo foo foo<Esc>0/foo<CR>')
+      eq({1, 1}, meths.win_get_cursor(0))
+      eq(1, eval('v:searchforward'))
+      feed('n')
+      eq({1, 5}, meths.win_get_cursor(0))
+      meths.set_vvar('searchforward', 0)
+      eq(0, eval('v:searchforward'))
+      feed('n')
+      eq({1, 1}, meths.win_get_cursor(0))
+      meths.set_vvar('searchforward', 1)
+      eq(1, eval('v:searchforward'))
+      feed('n')
+      eq({1, 5}, meths.win_get_cursor(0))
+
+      local screen = Screen.new(60, 3)
+      screen:set_default_attr_ids({
+        [0] = {bold = true, foreground = Screen.colors.Blue},
+        [1] = {background = Screen.colors.Yellow},
+      })
+      screen:attach()
+      eq(1, eval('v:hlsearch'))
+      screen:expect{grid=[[
+         {1:foo} {1:^foo} {1:foo}                                                |
+        {0:~                                                           }|
+                                                                    |
+      ]]}
+      meths.set_vvar('hlsearch', 0)
+      eq(0, eval('v:hlsearch'))
+      screen:expect{grid=[[
+         foo ^foo foo                                                |
+        {0:~                                                           }|
+                                                                    |
+      ]]}
+      meths.set_vvar('hlsearch', 1)
+      eq(1, eval('v:hlsearch'))
+      screen:expect{grid=[[
+         {1:foo} {1:^foo} {1:foo}                                                |
+        {0:~                                                           }|
+                                                                    |
+      ]]}
     end)
 
     it('vim_set_var returns the old value', function()
@@ -1358,56 +1426,71 @@ describe('API', function()
     end)
   end)
 
-  describe('nvim_get_option, nvim_set_option', function()
+  describe('nvim_get_option_value, nvim_set_option_value', function()
     it('works', function()
-      ok(nvim('get_option', 'equalalways'))
-      nvim('set_option', 'equalalways', false)
-      ok(not nvim('get_option', 'equalalways'))
+      ok(nvim('get_option_value', 'equalalways', {}))
+      nvim('set_option_value', 'equalalways', false, {})
+      ok(not nvim('get_option_value', 'equalalways', {}))
     end)
 
     it('works to get global value of local options', function()
-      eq(false, nvim('get_option', 'lisp'))
-      eq(8, nvim('get_option', 'shiftwidth'))
+      eq(false, nvim('get_option_value', 'lisp', {}))
+      eq(8, nvim('get_option_value', 'shiftwidth', {}))
     end)
 
     it('works to set global value of local options', function()
-      nvim('set_option', 'lisp', true)
-      eq(true, nvim('get_option', 'lisp'))
-      eq(false, helpers.curbuf('get_option', 'lisp'))
+      nvim('set_option_value', 'lisp', true, {scope='global'})
+      eq(true, nvim('get_option_value', 'lisp', {scope='global'}))
+      eq(false, nvim('get_option_value', 'lisp', {}))
       eq(nil, nvim('command_output', 'setglobal lisp?'):match('nolisp'))
       eq('nolisp', nvim('command_output', 'setlocal lisp?'):match('nolisp'))
-      nvim('set_option', 'shiftwidth', 20)
+      nvim('set_option_value', 'shiftwidth', 20, {scope='global'})
       eq('20', nvim('command_output', 'setglobal shiftwidth?'):match('%d+'))
       eq('8', nvim('command_output', 'setlocal shiftwidth?'):match('%d+'))
     end)
 
-    it('most window-local options have no global value', function()
-      local status, err = pcall(nvim, 'get_option', 'foldcolumn')
-      eq(false, status)
-      ok(err:match('Invalid option name') ~= nil)
-    end)
-
     it('updates where the option was last set from', function()
-      nvim('set_option', 'equalalways', false)
+      nvim('set_option_value', 'equalalways', false, {})
       local status, rv = pcall(nvim, 'command_output',
         'verbose set equalalways?')
       eq(true, status)
       ok(nil ~= string.find(rv, 'noequalalways\n'..
         '\tLast set from API client %(channel id %d+%)'))
 
-      nvim('exec_lua', 'vim.api.nvim_set_option("equalalways", true)', {})
+      nvim('exec_lua', 'vim.api.nvim_set_option_value("equalalways", true, {})', {})
       status, rv = pcall(nvim, 'command_output',
         'verbose set equalalways?')
       eq(true, status)
       eq('  equalalways\n\tLast set from Lua', rv)
     end)
-  end)
 
-  describe('nvim_get_option_value, nvim_set_option_value', function()
-    it('works', function()
-      ok(nvim('get_option_value', 'equalalways', {}))
-      nvim('set_option_value', 'equalalways', false, {})
-      ok(not nvim('get_option_value', 'equalalways', {}))
+    it('updates whether the option has ever been set #25025', function()
+      eq(false, nvim('get_option_info2', 'autochdir', {}).was_set)
+      nvim('set_option_value', 'autochdir', true, {})
+      eq(true, nvim('get_option_info2', 'autochdir', {}).was_set)
+
+      eq(false, nvim('get_option_info2', 'cmdwinheight', {}).was_set)
+      nvim('set_option_value', 'cmdwinheight', 10, {})
+      eq(true, nvim('get_option_info2', 'cmdwinheight', {}).was_set)
+
+      eq(false, nvim('get_option_info2', 'debug', {}).was_set)
+      nvim('set_option_value', 'debug', 'beep', {})
+      eq(true, nvim('get_option_info2', 'debug', {}).was_set)
+    end)
+
+    it('validation', function()
+      eq("Invalid 'scope': expected 'local' or 'global'",
+        pcall_err(nvim, 'get_option_value', 'scrolloff', {scope = 'bogus'}))
+      eq("Invalid 'scope': expected 'local' or 'global'",
+        pcall_err(nvim, 'set_option_value', 'scrolloff', 1, {scope = 'bogus'}))
+      eq("Invalid 'scope': expected String, got Integer",
+        pcall_err(nvim, 'get_option_value', 'scrolloff', {scope = 42}))
+      eq("Invalid 'value': expected valid option type, got Array",
+        pcall_err(nvim, 'set_option_value', 'scrolloff', {}, {}))
+      eq("Invalid value for option 'scrolloff': expected Number, got Boolean true",
+        pcall_err(nvim, 'set_option_value', 'scrolloff', true, {}))
+      eq("Invalid value for option 'scrolloff': expected Number, got String \"wrong\"",
+        pcall_err(nvim, 'set_option_value', 'scrolloff', 'wrong', {}))
     end)
 
     it('can get local values when global value is set', function()
@@ -1453,19 +1536,22 @@ describe('API', function()
 
       -- Now try with options with a special "local is unset" value (e.g. 'undolevels')
       nvim('set_option_value', 'undolevels', 1000, {})
-      eq(1000, nvim('get_option_value', 'undolevels', {scope = 'local'}))
+      nvim('set_option_value', 'undolevels', 1200, {scope = 'local'})
+      eq(1200, nvim('get_option_value', 'undolevels', {scope = 'local'}))
       nvim('set_option_value', 'undolevels', NIL, {scope = 'local'})
       eq(-123456, nvim('get_option_value', 'undolevels', {scope = 'local'}))
+      eq(1000, nvim('get_option_value', 'undolevels', {}))
 
       nvim('set_option_value', 'autoread', true, {})
-      eq(true, nvim('get_option_value', 'autoread', {scope = 'local'}))
+      nvim('set_option_value', 'autoread', false, {scope = 'local'})
+      eq(false, nvim('get_option_value', 'autoread', {scope = 'local'}))
       nvim('set_option_value', 'autoread', NIL, {scope = 'local'})
       eq(NIL, nvim('get_option_value', 'autoread', {scope = 'local'}))
+      eq(true, nvim('get_option_value', 'autoread', {}))
     end)
 
     it('set window options', function()
-      -- Same as to nvim_win_set_option
-      nvim('set_option_value', 'colorcolumn', '4,3', {win=0})
+      nvim('set_option_value', 'colorcolumn', '4,3', {})
       eq('4,3', nvim('get_option_value', 'colorcolumn', {scope = 'local'}))
       command("set modified hidden")
       command("enew") -- edit new buffer, window option is preserved
@@ -1473,7 +1559,6 @@ describe('API', function()
     end)
 
     it('set local window options', function()
-      -- Different to nvim_win_set_option
       nvim('set_option_value', 'colorcolumn', '4,3', {win=0, scope='local'})
       eq('4,3', nvim('get_option_value', 'colorcolumn', {win = 0, scope = 'local'}))
       command("set modified hidden")
@@ -1484,11 +1569,11 @@ describe('API', function()
     it('get buffer or window-local options', function()
       nvim('command', 'new')
       local buf = nvim('get_current_buf').id
-      nvim('buf_set_option', buf, 'tagfunc', 'foobar')
+      nvim('set_option_value', 'tagfunc', 'foobar', {buf=buf})
       eq('foobar', nvim('get_option_value', 'tagfunc', {buf = buf}))
 
       local win = nvim('get_current_win').id
-      nvim('win_set_option', win, 'number', true)
+      nvim('set_option_value', 'number', true, {win=win})
       eq(true, nvim('get_option_value', 'number', {win = win}))
     end)
 
@@ -1502,6 +1587,40 @@ describe('API', function()
       nvim('get_option_value', 'filetype', {buf = buf})
       eq({1, 9}, nvim('win_get_cursor', win))
     end)
+
+    it('can get default option values for filetypes', function()
+      command('filetype plugin on')
+      for ft, opts in pairs {
+        lua = { commentstring = '-- %s' },
+        vim = { commentstring = '"%s' },
+        man = { tagfunc = 'v:lua.require\'man\'.goto_tag' },
+        xml = { formatexpr = 'xmlformat#Format()' }
+      } do
+        for option, value in pairs(opts) do
+          eq(value, nvim('get_option_value', option, { filetype = ft }))
+        end
+      end
+
+      command'au FileType lua setlocal commentstring=NEW\\ %s'
+
+      eq('NEW %s', nvim('get_option_value', 'commentstring', { filetype = 'lua' }))
+    end)
+
+    it('errors for bad FileType autocmds', function()
+      command'au FileType lua setlocal commentstring=BAD'
+      eq([[FileType Autocommands for "lua": Vim(setlocal):E537: 'commentstring' must be empty or contain %s: commentstring=BAD]],
+         pcall_err(nvim, 'get_option_value', 'commentstring', { filetype = 'lua' }))
+    end)
+
+    it("value of 'modified' is always false for scratch buffers", function()
+      nvim('set_current_buf', nvim('create_buf', true, true))
+      insert([[
+        foo
+        bar
+        baz
+      ]])
+      eq(false, nvim('get_option_value', 'modified', {}))
+    end)
   end)
 
   describe('nvim_{get,set}_current_buf, nvim_list_bufs', function()
@@ -1774,15 +1893,32 @@ describe('API', function()
       feed('<C-D>')
       expect('a')  -- recognized i_0_CTRL-D
     end)
+
+    it("does not interrupt with 'digraph'", function()
+      command('set digraph')
+      feed('i,')
+      eq(2, eval('1+1'))  -- causes K_EVENT key
+      feed('<BS>')
+      eq(2, eval('1+1'))  -- causes K_EVENT key
+      feed('.')
+      expect('…')  -- digraph ",." worked
+      feed('<Esc>')
+      feed(':,')
+      eq(2, eval('1+1'))  -- causes K_EVENT key
+      feed('<BS>')
+      eq(2, eval('1+1'))  -- causes K_EVENT key
+      feed('.')
+      eq('…', funcs.getcmdline())  -- digraph ",." worked
+    end)
   end)
 
   describe('nvim_get_context', function()
-    it('validates args', function()
+    it('validation', function()
       eq("Invalid key: 'blah'",
         pcall_err(nvim, 'get_context', {blah={}}))
-      eq('invalid value for key: types',
+      eq("Invalid 'types': expected Array, got Integer",
         pcall_err(nvim, 'get_context', {types=42}))
-      eq('unexpected type: zub',
+      eq("Invalid 'type': 'zub'",
         pcall_err(nvim, 'get_context', {types={'jumps', 'zub', 'zam',}}))
     end)
     it('returns map of current editor state', function()
@@ -1843,6 +1979,13 @@ describe('API', function()
       nvim('load_context', ctx)
       eq({1, 2 ,3}, eval('[g:one, g:Two, g:THREE]'))
     end)
+
+    it('errors when context dictionary is invalid', function()
+      eq('E474: Failed to convert list to msgpack string buffer',
+         pcall_err(nvim, 'load_context', { regs = { {} }, jumps = { {} } }))
+      eq("Empty dictionary keys aren't allowed",
+         pcall_err(nvim, 'load_context', { regs = { { [''] = '' } } }))
+    end)
   end)
 
   describe('nvim_replace_termcodes', function()
@@ -1886,6 +2029,12 @@ describe('API', function()
       -- value.
       eq('', meths.replace_termcodes('', true, true, true))
     end)
+
+    -- Not exactly the case, as nvim_replace_termcodes() escapes K_SPECIAL in Unicode
+    it('translates the result of keytrans() on string with 0x80 byte back', function()
+      local s = 'ff\128\253\097tt'
+      eq(s, meths.replace_termcodes(funcs.keytrans(s), true, true, true))
+    end)
   end)
 
   describe('nvim_feedkeys', function()
@@ -1916,6 +2065,19 @@ describe('API', function()
   end)
 
   describe('nvim_out_write', function()
+    local screen
+
+    before_each(function()
+      screen = Screen.new(40, 8)
+      screen:attach()
+      screen:set_default_attr_ids({
+        [0] = {bold = true, foreground = Screen.colors.Blue},
+        [1] = {bold = true, foreground = Screen.colors.SeaGreen},
+        [2] = {bold = true, reverse = true},
+        [3] = {foreground = Screen.colors.Blue},
+      })
+    end)
+
     it('prints long messages correctly #20534', function()
       exec([[
         set more
@@ -1935,6 +2097,46 @@ describe('API', function()
       ]])
       eq('\naaa\n' .. ('a'):rep(5002) .. '\naaa', meths.get_var('out'))
     end)
+
+    it('blank line in message', function()
+      feed([[:call nvim_out_write("\na\n")<CR>]])
+      screen:expect{grid=[[
+                                                |
+        {0:~                                       }|
+        {0:~                                       }|
+        {0:~                                       }|
+        {2:                                        }|
+                                                |
+        a                                       |
+        {1:Press ENTER or type command to continue}^ |
+      ]]}
+      feed('<CR>')
+      feed([[:call nvim_out_write("b\n\nc\n")<CR>]])
+      screen:expect{grid=[[
+                                                |
+        {0:~                                       }|
+        {0:~                                       }|
+        {2:                                        }|
+        b                                       |
+                                                |
+        c                                       |
+        {1:Press ENTER or type command to continue}^ |
+      ]]}
+    end)
+
+    it('NUL bytes in message', function()
+      feed([[:lua vim.api.nvim_out_write('aaa\0bbb\0\0ccc\nddd\0\0\0eee\n')<CR>]])
+      screen:expect{grid=[[
+                                                |
+        {0:~                                       }|
+        {0:~                                       }|
+        {0:~                                       }|
+        {2:                                        }|
+        aaa{3:^@}bbb{3:^@^@}ccc                         |
+        ddd{3:^@^@^@}eee                            |
+        {1:Press ENTER or type command to continue}^ |
+      ]]}
+    end)
   end)
 
   describe('nvim_err_write', function()
@@ -2023,6 +2225,60 @@ describe('API', function()
       ]])
       feed('<cr>')  -- exit the press ENTER screen
     end)
+
+    it('NUL bytes in message', function()
+      nvim_async('err_write', 'aaa\0bbb\0\0ccc\nddd\0\0\0eee\n')
+      screen:expect{grid=[[
+                                                |
+        {0:~                                       }|
+        {0:~                                       }|
+        {0:~                                       }|
+        {3:                                        }|
+        {1:aaa^@bbb^@^@ccc}                         |
+        {1:ddd^@^@^@eee}                            |
+        {2:Press ENTER or type command to continue}^ |
+      ]]}
+    end)
+  end)
+
+  describe('nvim_err_writeln', function()
+    local screen
+
+    before_each(function()
+      screen = Screen.new(40, 8)
+      screen:attach()
+      screen:set_default_attr_ids({
+        [0] = {bold=true, foreground=Screen.colors.Blue},
+        [1] = {foreground = Screen.colors.White, background = Screen.colors.Red},
+        [2] = {bold = true, foreground = Screen.colors.SeaGreen},
+        [3] = {bold = true, reverse = true},
+      })
+    end)
+
+    it('shows only one return prompt after all lines are shown', function()
+      nvim_async('err_writeln', 'FAILURE\nERROR\nEXCEPTION\nTRACEBACK')
+      screen:expect([[
+                                                |
+        {0:~                                       }|
+        {3:                                        }|
+        {1:FAILURE}                                 |
+        {1:ERROR}                                   |
+        {1:EXCEPTION}                               |
+        {1:TRACEBACK}                               |
+        {2:Press ENTER or type command to continue}^ |
+      ]])
+      feed('<CR>')
+      screen:expect([[
+        ^                                        |
+        {0:~                                       }|
+        {0:~                                       }|
+        {0:~                                       }|
+        {0:~                                       }|
+        {0:~                                       }|
+        {0:~                                       }|
+                                                |
+      ]])
+    end)
   end)
 
   describe('nvim_list_chans, nvim_get_chan_info', function()
@@ -2115,7 +2371,7 @@ describe('API', function()
     it('stream=job :terminal channel', function()
       command(':terminal')
       eq({id=1}, meths.get_current_buf())
-      eq(3, meths.buf_get_option(1, 'channel'))
+      eq(3, meths.get_option_value('channel', {buf=1}))
 
       local info = {
         stream='job',
@@ -2223,15 +2479,14 @@ describe('API', function()
       eq(5, meths.get_var('avar'))
     end)
 
-    it('throws error on malformed arguments', function()
+    it('validation', function()
       local req = {
         {'nvim_set_var', {'avar', 1}},
         {'nvim_set_var'},
         {'nvim_set_var', {'avar', 2}},
       }
-      local status, err = pcall(meths.call_atomic, req)
-      eq(false, status)
-      ok(err:match('Items in calls array must be arrays of size 2') ~= nil)
+      eq("Invalid 'calls' item: expected 2-item Array",
+         pcall_err(meths.call_atomic, req))
       -- call before was done, but not after
       eq(1, meths.get_var('avar'))
 
@@ -2239,18 +2494,16 @@ describe('API', function()
         { 'nvim_set_var', { 'bvar', { 2, 3 } } },
         12,
       }
-      status, err = pcall(meths.call_atomic, req)
-      eq(false, status)
-      ok(err:match('Items in calls array must be arrays') ~= nil)
+      eq("Invalid 'calls' item: expected Array, got Integer",
+         pcall_err(meths.call_atomic, req))
       eq({2,3}, meths.get_var('bvar'))
 
       req = {
         {'nvim_set_current_line', 'little line'},
         {'nvim_set_var', {'avar', 3}},
       }
-      status, err = pcall(meths.call_atomic, req)
-      eq(false, status)
-      ok(err:match('Args must be Array') ~= nil)
+      eq("Invalid call args: expected Array, got String",
+         pcall_err(meths.call_atomic, req))
       -- call before was done, but not after
       eq(1, meths.get_var('avar'))
       eq({''}, meths.buf_get_lines(0, 0, -1, true))
@@ -2271,45 +2524,45 @@ describe('API', function()
     end)
 
     it('returns nothing with empty &runtimepath', function()
-      meths.set_option('runtimepath', '')
+      meths.set_option_value('runtimepath', '', {})
       eq({}, meths.list_runtime_paths())
     end)
     it('returns single runtimepath', function()
-      meths.set_option('runtimepath', 'a')
+      meths.set_option_value('runtimepath', 'a', {})
       eq({'a'}, meths.list_runtime_paths())
     end)
     it('returns two runtimepaths', function()
-      meths.set_option('runtimepath', 'a,b')
+      meths.set_option_value('runtimepath', 'a,b', {})
       eq({'a', 'b'}, meths.list_runtime_paths())
     end)
     it('returns empty strings when appropriate', function()
-      meths.set_option('runtimepath', 'a,,b')
+      meths.set_option_value('runtimepath', 'a,,b', {})
       eq({'a', '', 'b'}, meths.list_runtime_paths())
-      meths.set_option('runtimepath', ',a,b')
+      meths.set_option_value('runtimepath', ',a,b', {})
       eq({'', 'a', 'b'}, meths.list_runtime_paths())
       -- Trailing "," is ignored. Use ",," if you really really want CWD.
-      meths.set_option('runtimepath', 'a,b,')
+      meths.set_option_value('runtimepath', 'a,b,', {})
       eq({'a', 'b'}, meths.list_runtime_paths())
-      meths.set_option('runtimepath', 'a,b,,')
+      meths.set_option_value('runtimepath', 'a,b,,', {})
       eq({'a', 'b', ''}, meths.list_runtime_paths())
     end)
     it('truncates too long paths', function()
       local long_path = ('/a'):rep(8192)
-      meths.set_option('runtimepath', long_path)
+      meths.set_option_value('runtimepath', long_path, {})
       local paths_list = meths.list_runtime_paths()
       eq({}, paths_list)
     end)
   end)
 
   it('can throw exceptions', function()
-    local status, err = pcall(nvim, 'get_option', 'invalid-option')
+    local status, err = pcall(nvim, 'get_option_value', 'invalid-option', {})
     eq(false, status)
-    ok(err:match('Invalid option name') ~= nil)
+    ok(err:match("Unknown option 'invalid%-option'") ~= nil)
   end)
 
   it('does not truncate error message <1 MB #5984', function()
     local very_long_name = 'A'..('x'):rep(10000)..'Z'
-    local status, err = pcall(nvim, 'get_option', very_long_name)
+    local status, err = pcall(nvim, 'get_option_value', very_long_name, {})
     eq(false, status)
     eq(very_long_name, err:match('Ax+Z?'))
   end)
@@ -2322,7 +2575,7 @@ describe('API', function()
 
   describe('nvim_parse_expression', function()
     before_each(function()
-      meths.set_option('isident', '')
+      meths.set_option_value('isident', '', {})
     end)
 
     local function simplify_east_api_node(line, east_api_node)
@@ -2536,20 +2789,26 @@ describe('API', function()
         {
           chan = 1,
           ext_cmdline = false,
-          ext_popupmenu = false,
-          ext_tabline = false,
-          ext_wildmenu = false,
+          ext_hlstate = false,
           ext_linegrid = screen._options.ext_linegrid or false,
+          ext_messages = false,
           ext_multigrid = false,
-          ext_hlstate = false,
+          ext_popupmenu = false,
+          ext_tabline = false,
           ext_termcolors = false,
-          ext_messages = false,
+          ext_wildmenu = false,
           height = 4,
-          rgb = true,
           override = true,
+          rgb = true,
+          stdin_tty = false,
+          stdout_tty = false,
+          term_background = '',
+          term_colors = 0,
+          term_name = '',
           width = 20,
         }
       }
+
       eq(expected, nvim("list_uis"))
 
       screen:detach()
@@ -2601,9 +2860,9 @@ describe('API', function()
     end)
 
     it('can change buftype before visiting', function()
-      meths.set_option("hidden", false)
+      meths.set_option_value("hidden", false, {})
       eq({id=2}, meths.create_buf(true, false))
-      meths.buf_set_option(2, "buftype", "nofile")
+      meths.set_option_value("buftype", "nofile", {buf=2})
       meths.buf_set_lines(2, 0, -1, true, {"test text"})
       command("split | buffer 2")
       eq({id=2}, meths.get_current_buf())
@@ -2622,6 +2881,18 @@ describe('API', function()
       eq(false, eval('g:fired'))
     end)
 
+    it('TextChanged and TextChangedI do not trigger without changes', function()
+      local buf = meths.create_buf(true, false)
+      command([[let g:changed = '']])
+      meths.create_autocmd({'TextChanged', 'TextChangedI'}, {
+        buffer = buf,
+        command = 'let g:changed ..= mode()',
+      })
+      meths.set_current_buf(buf)
+      feed('i')
+      eq('', meths.get_var('changed'))
+    end)
+
     it('scratch-buffer', function()
       eq({id=2}, meths.create_buf(false, true))
       eq({id=3}, meths.create_buf(true, true))
@@ -2630,7 +2901,7 @@ describe('API', function()
       eq('  1 %a   "[No Name]"                    line 1\n'..
          '  3  h   "[Scratch]"                    line 0\n'..
          '  4  h   "[Scratch]"                    line 0',
-         meths.exec('ls', true))
+         exec_capture('ls'))
       -- current buffer didn't change
       eq({id=1}, meths.get_current_buf())
 
@@ -2646,10 +2917,10 @@ describe('API', function()
       local edited_buf = 2
       meths.buf_set_lines(edited_buf, 0, -1, true, {"some text"})
       for _,b in ipairs(scratch_bufs) do
-        eq('nofile', meths.buf_get_option(b, 'buftype'))
-        eq('hide', meths.buf_get_option(b, 'bufhidden'))
-        eq(false, meths.buf_get_option(b, 'swapfile'))
-        eq(false, meths.buf_get_option(b, 'modeline'))
+        eq('nofile', meths.get_option_value('buftype', {buf=b}))
+        eq('hide', meths.get_option_value('bufhidden', {buf=b}))
+        eq(false, meths.get_option_value('swapfile', {buf=b}))
+        eq(false, meths.get_option_value('modeline', {buf=b}))
       end
 
       --
@@ -2662,10 +2933,10 @@ describe('API', function()
         {1:~                   }|
                             |
       ]])
-      eq('nofile', meths.buf_get_option(edited_buf, 'buftype'))
-      eq('hide', meths.buf_get_option(edited_buf, 'bufhidden'))
-      eq(false, meths.buf_get_option(edited_buf, 'swapfile'))
-      eq(false, meths.buf_get_option(edited_buf, 'modeline'))
+      eq('nofile', meths.get_option_value('buftype', {buf=edited_buf}))
+      eq('hide', meths.get_option_value('bufhidden', {buf=edited_buf}))
+      eq(false, meths.get_option_value('swapfile', {buf=edited_buf}))
+      eq(false, meths.get_option_value('modeline', {buf=edited_buf}))
 
       -- Scratch buffer can be wiped without error.
       command('bwipe')
@@ -2679,7 +2950,9 @@ describe('API', function()
 
     it('does not cause heap-use-after-free on exit while setting options', function()
       command('au OptionSet * q')
-      expect_exit(command, 'silent! call nvim_create_buf(0, 1)')
+      command('silent! call nvim_create_buf(0, 1)')
+      -- nowadays this works because we don't execute any spurious autocmds at all #24824
+      assert_alive()
     end)
   end)
 
@@ -2744,13 +3017,13 @@ describe('API', function()
     end)
 
     it('should not crash when echoed', function()
-      meths.exec("echo nvim_get_all_options_info()", true)
+      meths.exec2("echo nvim_get_all_options_info()", { output = true })
     end)
   end)
 
   describe('nvim_get_option_info', function()
     it('should error for unknown options', function()
-      eq("no such option: 'bogus'", pcall_err(meths.get_option_info, 'bogus'))
+      eq("Invalid option (not found): 'bogus'", pcall_err(meths.get_option_info, 'bogus'))
     end)
 
     it('should return the same options for short and long name', function()
@@ -2796,7 +3069,7 @@ describe('API', function()
     it('should have information about global options', function()
       -- precondition: the option was changed from its default
       -- in test setup.
-      eq(false, meths.get_option'showcmd')
+      eq(false, meths.get_option_value('showcmd', {}))
 
       eq({
         allows_duplicates = true,
@@ -2813,6 +3086,117 @@ describe('API', function()
         type = "boolean",
         was_set = true
       }, meths.get_option_info'showcmd')
+
+      meths.set_option_value('showcmd', true, {})
+
+      eq({
+        allows_duplicates = true,
+        commalist = false,
+        default = true,
+        flaglist = false,
+        global_local = false,
+        last_set_chan = 1,
+        last_set_linenr = 0,
+        last_set_sid = -9,
+        name = "showcmd",
+        scope = "global",
+        shortname = "sc",
+        type = "boolean",
+        was_set = true
+      }, meths.get_option_info'showcmd')
+    end)
+  end)
+
+  describe('nvim_get_option_info2', function()
+    local fname
+    local bufs
+    local wins
+
+    before_each(function()
+      fname = tmpname()
+      write_file(fname, [[
+        setglobal dictionary=mydict " 1, global-local (buffer)
+        setlocal  formatprg=myprg   " 2, global-local (buffer)
+        setglobal equalprg=prg1     " 3, global-local (buffer)
+        setlocal  equalprg=prg2     " 4, global-local (buffer)
+        setglobal fillchars=stl:x   " 5, global-local (window)
+        setlocal  listchars=eol:c   " 6, global-local (window)
+        setglobal showbreak=aaa     " 7, global-local (window)
+        setlocal  showbreak=bbb     " 8, global-local (window)
+        setglobal completeopt=menu  " 9, global
+      ]])
+
+      exec_lua 'vim.cmd.vsplit()'
+      meths.create_buf(false, false)
+
+      bufs = meths.list_bufs()
+      wins = meths.list_wins()
+
+      meths.win_set_buf(wins[1].id, bufs[1].id)
+      meths.win_set_buf(wins[2].id, bufs[2].id)
+
+      meths.set_current_win(wins[2].id)
+      meths.exec('source ' .. fname, false)
+
+      meths.set_current_win(wins[1].id)
+    end)
+
+    after_each(function()
+      os.remove(fname)
+    end)
+
+    it('should return option information', function()
+      eq(meths.get_option_info('dictionary'),  meths.get_option_info2('dictionary',  {})) -- buffer
+      eq(meths.get_option_info('fillchars'),   meths.get_option_info2('fillchars',   {})) -- window
+      eq(meths.get_option_info('completeopt'), meths.get_option_info2('completeopt', {})) -- global
+    end)
+
+    describe('last set', function()
+      local tests = {
+        {desc="(buf option, global requested, global set) points to global",   linenr=1, sid=1, args={'dictionary', {scope='global'}}},
+        {desc="(buf option, global requested, local set) is not set",          linenr=0, sid=0, args={'formatprg',  {scope='global'}}},
+        {desc="(buf option, global requested, both set) points to global",     linenr=3, sid=1, args={'equalprg',   {scope='global'}}},
+        {desc="(buf option, local requested, global set) is not set",          linenr=0, sid=0, args={'dictionary', {scope='local'}}},
+        {desc="(buf option, local requested, local set) points to local",      linenr=2, sid=1, args={'formatprg',  {scope='local'}}},
+        {desc="(buf option, local requested, both set) points to local",       linenr=4, sid=1, args={'equalprg',   {scope='local'}}},
+        {desc="(buf option, fallback requested, global set) points to global", linenr=1, sid=1, args={'dictionary', {}}},
+        {desc="(buf option, fallback requested, local set) points to local",   linenr=2, sid=1, args={'formatprg',  {}}},
+        {desc="(buf option, fallback requested, both set) points to local",    linenr=4, sid=1, args={'equalprg',   {}}},
+        {desc="(win option, global requested, global set) points to global",   linenr=5, sid=1, args={'fillchars', {scope='global'}}},
+        {desc="(win option, global requested, local set) is not set",          linenr=0, sid=0, args={'listchars', {scope='global'}}},
+        {desc="(win option, global requested, both set) points to global",     linenr=7, sid=1, args={'showbreak', {scope='global'}}},
+        {desc="(win option, local requested, global set) is not set",          linenr=0, sid=0, args={'fillchars', {scope='local'}}},
+        {desc="(win option, local requested, local set) points to local",      linenr=6, sid=1, args={'listchars', {scope='local'}}},
+        {desc="(win option, local requested, both set) points to local",       linenr=8, sid=1, args={'showbreak', {scope='local'}}},
+        {desc="(win option, fallback requested, global set) points to global", linenr=5, sid=1, args={'fillchars', {}}},
+        {desc="(win option, fallback requested, local set) points to local",   linenr=6, sid=1, args={'listchars', {}}},
+        {desc="(win option, fallback requested, both set) points to local",    linenr=8, sid=1, args={'showbreak', {}}},
+        {desc="(global option, global requested) points to global",            linenr=9, sid=1, args={'completeopt', {scope='global'}}},
+        {desc="(global option, local requested) is not set",                   linenr=0, sid=0, args={'completeopt', {scope='local'}}},
+        {desc="(global option, fallback requested) points to global",          linenr=9, sid=1, args={'completeopt', {}}},
+      }
+
+      for _, t in pairs(tests) do
+        it(t.desc, function()
+          -- Switch to the target buffer/window so that curbuf/curwin are used.
+          meths.set_current_win(wins[2].id)
+          local info = meths.get_option_info2(unpack(t.args))
+          eq(t.linenr, info.last_set_linenr)
+          eq(t.sid, info.last_set_sid)
+        end)
+      end
+
+      it('is provided for cross-buffer requests', function()
+        local info = meths.get_option_info2('formatprg', {buf=bufs[2].id})
+        eq(2, info.last_set_linenr)
+        eq(1, info.last_set_sid)
+      end)
+
+      it('is provided for cross-window requests', function()
+        local info = meths.get_option_info2('listchars', {win=wins[2].id})
+        eq(6, info.last_set_linenr)
+        eq(1, info.last_set_sid)
+      end)
     end)
   end)
 
@@ -2820,11 +3204,10 @@ describe('API', function()
     local screen
 
     before_each(function()
-      clear()
       screen = Screen.new(40, 8)
       screen:attach()
       screen:set_default_attr_ids({
-        [0] = {bold=true, foreground=Screen.colors.Blue},
+        [0] = {bold = true, foreground = Screen.colors.Blue},
         [1] = {bold = true, foreground = Screen.colors.SeaGreen},
         [2] = {bold = true, reverse = true},
         [3] = {foreground = Screen.colors.Brown, bold = true}, -- Statement
@@ -2879,13 +3262,13 @@ describe('API', function()
     it('can save message history', function()
       nvim('command', 'set cmdheight=2') -- suppress Press ENTER
       nvim("echo", {{"msg\nmsg"}, {"msg"}}, true, {})
-      eq("msg\nmsgmsg", meths.exec('messages', true))
+      eq("msg\nmsgmsg", exec_capture('messages'))
     end)
 
     it('can disable saving message history', function()
       nvim('command', 'set cmdheight=2') -- suppress Press ENTER
       nvim_async("echo", {{"msg\nmsg"}, {"msg"}}, false, {})
-      eq("", meths.exec("messages", true))
+      eq("", exec_capture('messages'))
     end)
   end)
 
@@ -2894,7 +3277,6 @@ describe('API', function()
     local screen
 
     before_each(function()
-      clear()
       screen = Screen.new(100, 35)
       screen:attach()
       screen:set_default_attr_ids({
@@ -3031,10 +3413,10 @@ describe('API', function()
       eq(true, meths.del_mark('F'))
       eq({0, 0}, meths.buf_get_mark(buf, 'F'))
     end)
-    it('fails when invalid marks are used', function()
-      eq(false, pcall(meths.del_mark, 'f'))
-      eq(false, pcall(meths.del_mark, '!'))
-      eq(false, pcall(meths.del_mark, 'fail'))
+    it('validation', function()
+      eq("Invalid mark name (must be file/uppercase): 'f'", pcall_err(meths.del_mark, 'f'))
+      eq("Invalid mark name (must be file/uppercase): '!'", pcall_err(meths.del_mark, '!'))
+      eq("Invalid mark name (must be a single char): 'fail'", pcall_err(meths.del_mark, 'fail'))
     end)
   end)
   describe('nvim_get_mark', function()
@@ -3048,10 +3430,10 @@ describe('API', function()
       assert(string.find(mark[4], "mybuf$"))
       eq({2, 2, buf.id, mark[4]}, mark)
     end)
-    it('fails when invalid marks are used', function()
-      eq(false, pcall(meths.del_mark, 'f'))
-      eq(false, pcall(meths.del_mark, '!'))
-      eq(false, pcall(meths.del_mark, 'fail'))
+    it('validation', function()
+      eq("Invalid mark name (must be file/uppercase): 'f'", pcall_err(meths.get_mark, 'f', {}))
+      eq("Invalid mark name (must be file/uppercase): '!'", pcall_err(meths.get_mark, '!', {}))
+      eq("Invalid mark name (must be a single char): 'fail'", pcall_err(meths.get_mark, 'fail', {}))
     end)
     it('returns the expected when mark is not set', function()
       eq(true, meths.del_mark('A'))
@@ -3113,15 +3495,15 @@ describe('API', function()
          meths.eval_statusline('a%=b', { fillchar = '\031', maxwidth = 5 }))
     end)
     it('rejects multiple-character fillchar', function()
-      eq('fillchar must be a single character',
+      eq("Invalid 'fillchar': expected single character",
          pcall_err(meths.eval_statusline, '', { fillchar = 'aa' }))
     end)
     it('rejects empty string fillchar', function()
-      eq('fillchar must be a single character',
+      eq("Invalid 'fillchar': expected single character",
          pcall_err(meths.eval_statusline, '', { fillchar = '' }))
     end)
     it('rejects non-string fillchar', function()
-      eq('fillchar must be a single character',
+      eq("Invalid 'fillchar': expected String, got Integer",
          pcall_err(meths.eval_statusline, '', { fillchar = 1 }))
     end)
     it('rejects invalid string', function()
@@ -3213,6 +3595,38 @@ describe('API', function()
             'TextWithNoHighlight%#WarningMsg#TextWithWarningHighlight',
             { use_winbar = true, highlights = true }))
       end)
+      it('works with statuscolumn', function()
+        exec([[
+          let &stc='%C%s%=%l '
+          set cul nu nuw=3 scl=yes:2 fdc=2
+          call setline(1, repeat(['aaaaa'], 5))
+          let g:ns = nvim_create_namespace('')
+          call sign_define('a', {'text':'aa', 'texthl':'IncSearch', 'numhl':'Normal'})
+          call sign_place(2, 1, 'a', bufnr(), {'lnum':4})
+          call nvim_buf_set_extmark(0, g:ns, 3, 1, { 'sign_text':'bb', 'sign_hl_group':'ErrorMsg' })
+          1,5fold | 1,5 fold | foldopen!
+          norm 4G
+        ]])
+        eq({
+          str = '││aabb 4 ',
+          width = 9,
+          highlights = {
+            { group = 'CursorLineFold', start = 0 },
+            { group = 'Normal', start = 6 },
+            { group = 'IncSearch', start = 6 },
+            { group = 'ErrorMsg', start = 8 },
+            { group = 'Normal', start = 10 }
+          }
+        }, meths.eval_statusline('%C%s%=%l ', { use_statuscol_lnum = 4, highlights = true }))
+        eq({
+          str = '3 ' ,
+          width = 2,
+          highlights = {
+            { group = 'LineNr', start = 0 },
+            { group = 'ErrorMsg', start = 1 }
+          }
+        }, meths.eval_statusline('%l%#ErrorMsg# ', { use_statuscol_lnum = 3, highlights = true }))
+      end)
       it('no memory leak with click functions', function()
         meths.eval_statusline('%@ClickFunc@StatusLineStringWithClickFunc%T', {})
         eq({
@@ -3226,6 +3640,7 @@ describe('API', function()
       end)
     end)
   end)
+
   describe('nvim_parse_cmd', function()
     it('works', function()
       eq({
@@ -3708,7 +4123,7 @@ describe('API', function()
         }
       }, meths.parse_cmd('MyCommand test it', {}))
     end)
-    it('errors for invalid command', function()
+    it('validates command', function()
       eq('Error while parsing command line', pcall_err(meths.parse_cmd, '', {}))
       eq('Error while parsing command line', pcall_err(meths.parse_cmd, '" foo', {}))
       eq('Error while parsing command line: E492: Not an editor command: Fubar',
@@ -3807,20 +4222,87 @@ describe('API', function()
       meths.cmd(meths.parse_cmd("set cursorline", {}), {})
       eq(true, meths.get_option_value("cursorline", {}))
     end)
+    it('no side-effects (error messages) in pcall() #20339', function()
+      eq({ false, 'Error while parsing command line: E16: Invalid range' },
+        exec_lua([=[return {pcall(vim.api.nvim_parse_cmd, "'<,'>n", {})}]=]))
+      eq('', eval('v:errmsg'))
+    end)
   end)
+
   describe('nvim_cmd', function()
     it('works', function ()
       meths.cmd({ cmd = "set", args = { "cursorline" } }, {})
       eq(true, meths.get_option_value("cursorline", {}))
     end)
+
+    it('validation', function()
+      eq("Invalid 'cmd': expected non-empty String",
+        pcall_err(meths.cmd, { cmd = ""}, {}))
+      eq("Invalid 'cmd': expected String, got Array",
+        pcall_err(meths.cmd, { cmd = {}}, {}))
+      eq("Invalid 'args': expected Array, got Boolean",
+        pcall_err(meths.cmd, { cmd = "set", args = true }, {}))
+      eq("Invalid command arg: expected non-whitespace",
+        pcall_err(meths.cmd, { cmd = "set", args = {'  '}, }, {}))
+      eq("Invalid command arg: expected valid type, got Array",
+        pcall_err(meths.cmd, { cmd = "set", args = {{}}, }, {}))
+      eq("Wrong number of arguments",
+        pcall_err(meths.cmd, { cmd = "aboveleft", args = {}, }, {}))
+      eq("Command cannot accept bang: print",
+        pcall_err(meths.cmd, { cmd = "print", args = {}, bang = true }, {}))
+
+      eq("Command cannot accept range: set",
+        pcall_err(meths.cmd, { cmd = "set", args = {}, range = {1} }, {}))
+      eq("Invalid 'range': expected Array, got Boolean",
+        pcall_err(meths.cmd, { cmd = "print", args = {}, range = true }, {}))
+      eq("Invalid 'range': expected <=2 elements",
+        pcall_err(meths.cmd, { cmd = "print", args = {}, range = {1,2,3,4} }, {}))
+      eq("Invalid range element: expected non-negative Integer",
+        pcall_err(meths.cmd, { cmd = "print", args = {}, range = {-1} }, {}))
+
+      eq("Command cannot accept count: set",
+        pcall_err(meths.cmd, { cmd = "set", args = {}, count = 1 }, {}))
+      eq("Invalid 'count': expected Integer, got Boolean",
+        pcall_err(meths.cmd, { cmd = "print", args = {}, count = true }, {}))
+      eq("Invalid 'count': expected non-negative Integer",
+        pcall_err(meths.cmd, { cmd = "print", args = {}, count = -1 }, {}))
+
+      eq("Command cannot accept register: set",
+        pcall_err(meths.cmd, { cmd = "set", args = {}, reg = 'x' }, {}))
+      eq('Cannot use register "=',
+        pcall_err(meths.cmd, { cmd = "put", args = {}, reg = '=' }, {}))
+      eq("Invalid 'reg': expected single character, got xx",
+        pcall_err(meths.cmd, { cmd = "put", args = {}, reg = 'xx' }, {}))
+
+      -- #20681
+      eq('Invalid command: "win_getid"', pcall_err(meths.cmd, { cmd = 'win_getid'}, {}))
+      eq('Invalid command: "echo "hi""', pcall_err(meths.cmd, { cmd = 'echo "hi"'}, {}))
+      eq('Invalid command: "win_getid"', pcall_err(exec_lua, [[return vim.cmd.win_getid{}]]))
+
+      -- Lua call allows empty {} for dict item.
+      eq('', exec_lua([[return vim.cmd{ cmd = "set", args = {}, magic = {} }]]))
+      eq('', exec_lua([[return vim.cmd{ cmd = "set", args = {}, mods = {} }]]))
+      eq('', meths.cmd({ cmd = "set", args = {}, magic = {} }, {}))
+
+      -- Lua call does not allow non-empty list-like {} for dict item.
+      eq("Invalid 'magic': Expected Dict-like Lua table",
+        pcall_err(exec_lua, [[return vim.cmd{ cmd = "set", args = {}, magic = { 'a' } }]]))
+      eq("Invalid key: 'bogus'",
+        pcall_err(exec_lua, [[return vim.cmd{ cmd = "set", args = {}, magic = { bogus = true } }]]))
+      eq("Invalid key: 'bogus'",
+        pcall_err(exec_lua, [[return vim.cmd{ cmd = "set", args = {}, mods = { bogus = true } }]]))
+    end)
+
     it('captures output', function()
       eq("foo", meths.cmd({ cmd = "echo", args = { '"foo"' } }, { output = true }))
     end)
+
     it('sets correct script context', function()
       meths.cmd({ cmd = "set", args = { "cursorline" } }, {})
-      local str = meths.exec([[verbose set cursorline?]], true)
+      local str = exec_capture([[verbose set cursorline?]])
       neq(nil, str:find("cursorline\n\tLast set from API client %(channel id %d+%)"))
     end)
+
     it('works with range', function()
       insert [[
         line1
@@ -3867,7 +4349,7 @@ describe('API', function()
         line6
       ]]
       meths.cmd({ cmd = "del", range = { 2, 4 }, reg = 'a' }, {})
-      meths.exec("1put a", false)
+      command('1put a')
       expect [[
         line1
         line2
@@ -3914,7 +4396,7 @@ describe('API', function()
          meths.cmd({ cmd = "buffers", mods = { filter = { pattern = "foo", force = true } } },
                    { output = true }))
 
-      -- with emsg_silent = true error is suppresed
+      -- with emsg_silent = true error is suppressed
       feed([[:lua vim.api.nvim_cmd({ cmd = 'call', mods = { emsg_silent = true } }, {})<CR>]])
       eq('', meths.cmd({ cmd = 'messages' }, { output = true }))
       -- error from the next command typed is not suppressed #21420
@@ -3927,16 +4409,16 @@ describe('API', function()
           vim.api.nvim_echo({{ opts.fargs[1] }}, false, {})
         end, { nargs = 1 })
       ]])
-      eq(lfs.currentdir(),
+      eq(luv.cwd(),
          meths.cmd({ cmd = "Foo", args = { '%:p:h' }, magic = { file = true } },
                    { output = true }))
     end)
     it('splits arguments correctly', function()
-      meths.exec([[
+      exec([[
         function! FooFunc(...)
           echo a:000
         endfunction
-      ]], false)
+      ]])
       meths.create_user_command("Foo", "call FooFunc(<f-args>)", { nargs = '+' })
       eq([=[['a quick', 'brown fox', 'jumps over the', 'lazy dog']]=],
          meths.cmd({ cmd = "Foo", args = { "a quick", "brown fox", "jumps over the", "lazy dog"}},
@@ -3948,7 +4430,7 @@ describe('API', function()
     it('splits arguments correctly for Lua callback', function()
       meths.exec_lua([[
         local function FooFunc(opts)
-          vim.pretty_print(opts.fargs)
+          vim.print(opts.fargs)
         end
 
         vim.api.nvim_create_user_command("Foo", FooFunc, { nargs = '+' })
@@ -4054,8 +4536,6 @@ describe('API', function()
       eq('1', meths.cmd({cmd = 'echo', args = {true}}, {output = true}))
     end)
     describe('first argument as count', function()
-      before_each(clear)
-
       it('works', function()
         command('vsplit | enew')
         meths.cmd({cmd = 'bdelete', args = {meths.get_current_buf()}}, {})
diff --git a/test/functional/api/window_spec.lua b/test/functional/api/window_spec.lua
index ecab6a4713..6737c2d15b 100644
--- a/test/functional/api/window_spec.lua
+++ b/test/functional/api/window_spec.lua
@@ -43,6 +43,25 @@ describe('API/win', function()
       eq('Invalid buffer id: 23', pcall_err(window, 'set_buf', nvim('get_current_win'), 23))
       eq('Invalid window id: 23', pcall_err(window, 'set_buf', 23, nvim('get_current_buf')))
     end)
+
+    it('disallowed in cmdwin if win={old_}curwin or buf=curbuf', function()
+      local new_buf = meths.create_buf(true, true)
+      local old_win = meths.get_current_win()
+      local new_win = meths.open_win(new_buf, false, {
+        relative='editor', row=10, col=10, width=50, height=10,
+      })
+      feed('q:')
+      eq('E11: Invalid in command-line window; <CR> executes, CTRL-C quits',
+         pcall_err(meths.win_set_buf, 0, new_buf))
+      eq('E11: Invalid in command-line window; <CR> executes, CTRL-C quits',
+         pcall_err(meths.win_set_buf, old_win, new_buf))
+      eq('E11: Invalid in command-line window; <CR> executes, CTRL-C quits',
+         pcall_err(meths.win_set_buf, new_win, 0))
+
+      local next_buf = meths.create_buf(true, true)
+      meths.win_set_buf(new_win, next_buf)
+      eq(next_buf, meths.win_get_buf(new_win))
+    end)
   end)
 
   describe('{get,set}_cursor', function()
@@ -285,6 +304,22 @@ describe('API/win', function()
       eq(2, window('get_height', nvim('list_wins')[2]))
     end)
 
+    it('correctly handles height=1', function()
+      nvim('command', 'split')
+      nvim('set_current_win', nvim('list_wins')[1])
+      window('set_height', nvim('list_wins')[2], 1)
+      eq(1, window('get_height', nvim('list_wins')[2]))
+    end)
+
+    it('correctly handles height=1 with a winbar', function()
+      nvim('command', 'set winbar=foobar')
+      nvim('command', 'set winminheight=0')
+      nvim('command', 'split')
+      nvim('set_current_win', nvim('list_wins')[1])
+      window('set_height', nvim('list_wins')[2], 1)
+      eq(1, window('get_height', nvim('list_wins')[2]))
+    end)
+
     it('do not cause ml_get errors with foldmethod=expr #19989', function()
       insert([[
         aaaaa
@@ -363,22 +398,22 @@ describe('API/win', function()
     end)
   end)
 
-  describe('nvim_win_get_option, nvim_win_set_option', function()
+  describe('nvim_get_option_value, nvim_set_option_value', function()
     it('works', function()
-      curwin('set_option', 'colorcolumn', '4,3')
-      eq('4,3', curwin('get_option', 'colorcolumn'))
+      nvim('set_option_value', 'colorcolumn', '4,3', {})
+      eq('4,3', nvim('get_option_value', 'colorcolumn', {}))
       command("set modified hidden")
       command("enew") -- edit new buffer, window option is preserved
-      eq('4,3', curwin('get_option', 'colorcolumn'))
+      eq('4,3', nvim('get_option_value', 'colorcolumn', {}))
 
       -- global-local option
-      curwin('set_option', 'statusline', 'window-status')
-      eq('window-status', curwin('get_option', 'statusline'))
-      eq('', nvim('get_option', 'statusline'))
+      nvim('set_option_value', 'statusline', 'window-status', {win=0})
+      eq('window-status', nvim('get_option_value', 'statusline', {win=0}))
+      eq('', nvim('get_option_value', 'statusline', {scope='global'}))
       command("set modified")
       command("enew") -- global-local: not preserved in new buffer
       -- confirm local value was not copied
-      eq('', curwin('get_option', 'statusline'))
+      eq('', nvim('get_option_value', 'statusline', {win = 0}))
       eq('', eval('&l:statusline'))
     end)
 
@@ -386,16 +421,16 @@ describe('API/win', function()
       nvim('command', 'tabnew')
       local tab1 = unpack(nvim('list_tabpages'))
       local win1 = unpack(tabpage('list_wins', tab1))
-      window('set_option', win1, 'statusline', 'window-status')
+      nvim('set_option_value', 'statusline', 'window-status', {win=win1.id})
       nvim('command', 'split')
       nvim('command', 'wincmd J')
       nvim('command', 'wincmd j')
-      eq('window-status', window('get_option', win1, 'statusline'))
+      eq('window-status', nvim('get_option_value', 'statusline', {win = win1.id}))
       assert_alive()
     end)
 
     it('returns values for unset local options', function()
-      eq(-1, curwin('get_option', 'scrolloff'))
+      eq(-1, nvim('get_option_value', 'scrolloff', {win=0, scope='local'}))
     end)
   end)
 
@@ -508,15 +543,21 @@ describe('API/win', function()
       command('split')
       eq(2, #meths.list_wins())
       local oldwin = meths.get_current_win()
+      local otherwin = meths.open_win(0, false, {
+        relative='editor', row=10, col=10, width=10, height=10,
+      })
       -- Open cmdline-window.
       feed('q:')
-      eq(3, #meths.list_wins())
+      eq(4, #meths.list_wins())
       eq(':', funcs.getcmdwintype())
-      -- Vim: not allowed to close other windows from cmdline-window.
+      -- Not allowed to close previous window from cmdline-window.
       eq('E11: Invalid in command-line window; <CR> executes, CTRL-C quits',
-        pcall_err(meths.win_close, oldwin, true))
+         pcall_err(meths.win_close, oldwin, true))
+      -- Closing other windows is fine.
+      meths.win_close(otherwin, true)
+      eq(false, meths.win_is_valid(otherwin))
       -- Close cmdline-window.
-      meths.win_close(0,true)
+      meths.win_close(0, true)
       eq(2, #meths.list_wins())
       eq('', funcs.getcmdwintype())
     end)
@@ -568,15 +609,247 @@ describe('API/win', function()
     it('deletes the buffer when bufhidden=wipe', function()
       local oldwin = meths.get_current_win()
       local oldbuf = meths.get_current_buf()
-      local buf = meths.create_buf(true, false)
+      local buf = meths.create_buf(true, false).id
       local newwin = meths.open_win(buf, true, {
         relative='win', row=3, col=3, width=12, height=3
       })
-      meths.buf_set_option(buf, 'bufhidden', 'wipe')
+      meths.set_option_value('bufhidden', 'wipe', {buf=buf})
       meths.win_hide(newwin)
       eq({oldwin}, meths.list_wins())
       eq({oldbuf}, meths.list_bufs())
     end)
+    it('in the cmdwin', function()
+      feed('q:')
+      -- Can close the cmdwin.
+      meths.win_hide(0)
+      eq('', funcs.getcmdwintype())
+
+      local old_win = meths.get_current_win()
+      local other_win = meths.open_win(0, false, {
+        relative='win', row=3, col=3, width=12, height=3
+      })
+      feed('q:')
+      -- Cannot close the previous window.
+      eq('E11: Invalid in command-line window; <CR> executes, CTRL-C quits',
+         pcall_err(meths.win_hide, old_win))
+      -- Can close other windows.
+      meths.win_hide(other_win)
+      eq(false, meths.win_is_valid(other_win))
+    end)
+  end)
+
+  describe('text_height', function()
+    it('validation', function()
+      local X = meths.get_vvar('maxcol')
+      insert([[
+        aaa
+        bbb
+        ccc
+        ddd
+        eee]])
+      eq("Invalid window id: 23",
+         pcall_err(meths.win_text_height, 23, {}))
+      eq("Line index out of bounds",
+         pcall_err(curwinmeths.text_height, { start_row = 5 }))
+      eq("Line index out of bounds",
+         pcall_err(curwinmeths.text_height, { start_row = -6 }))
+      eq("Line index out of bounds",
+         pcall_err(curwinmeths.text_height, { end_row = 5 }))
+      eq("Line index out of bounds",
+         pcall_err(curwinmeths.text_height, { end_row = -6 }))
+      eq("'start_row' is higher than 'end_row'",
+         pcall_err(curwinmeths.text_height, { start_row = 3, end_row = 1 }))
+      eq("'start_vcol' specified without 'start_row'",
+         pcall_err(curwinmeths.text_height, { end_row = 2, start_vcol = 0 }))
+      eq("'end_vcol' specified without 'end_row'",
+         pcall_err(curwinmeths.text_height, { start_row = 2, end_vcol = 0 }))
+      eq("Invalid 'start_vcol': out of range",
+         pcall_err(curwinmeths.text_height, { start_row = 2, start_vcol = -1 }))
+      eq("Invalid 'start_vcol': out of range",
+         pcall_err(curwinmeths.text_height, { start_row = 2, start_vcol = X + 1 }))
+      eq("Invalid 'end_vcol': out of range",
+         pcall_err(curwinmeths.text_height, { end_row = 2, end_vcol = -1 }))
+      eq("Invalid 'end_vcol': out of range",
+         pcall_err(curwinmeths.text_height, { end_row = 2, end_vcol = X + 1 }))
+      eq("'start_vcol' is higher than 'end_vcol'",
+         pcall_err(curwinmeths.text_height, { start_row = 2, end_row = 2, start_vcol = 10, end_vcol = 5 }))
+    end)
+
+    it('with two diff windows', function()
+      local X = meths.get_vvar('maxcol')
+      local screen = Screen.new(45, 22)
+      screen:set_default_attr_ids({
+        [0] = {foreground = Screen.colors.Blue1, bold = true};
+        [1] = {foreground = Screen.colors.Blue4, background = Screen.colors.Grey};
+        [2] = {foreground = Screen.colors.Brown};
+        [3] = {foreground = Screen.colors.Blue1, background = Screen.colors.LightCyan1, bold = true};
+        [4] = {background = Screen.colors.LightBlue};
+        [5] = {foreground = Screen.colors.Blue4, background = Screen.colors.LightGrey};
+        [6] = {background = Screen.colors.Plum1};
+        [7] = {background = Screen.colors.Red, bold = true};
+        [8] = {reverse = true};
+        [9] = {bold = true, reverse = true};
+      })
+      screen:attach()
+      exec([[
+        set diffopt+=context:2 number
+        let expr = 'printf("%08d", v:val) .. repeat("!", v:val)'
+        call setline(1, map(range(1, 20) + range(25, 45), expr))
+        vnew
+        call setline(1, map(range(3, 20) + range(28, 50), expr))
+        windo diffthis
+      ]])
+      feed('24gg')
+      screen:expect{grid=[[
+        {1:  }{2:    }{3:----------------}│{1:  }{2:  1 }{4:00000001!       }|
+        {1:  }{2:    }{3:----------------}│{1:  }{2:  2 }{4:00000002!!      }|
+        {1:  }{2:  1 }00000003!!!     │{1:  }{2:  3 }00000003!!!     |
+        {1:  }{2:  2 }00000004!!!!    │{1:  }{2:  4 }00000004!!!!    |
+        {1:+ }{2:  3 }{5:+-- 14 lines: 00}│{1:+ }{2:  5 }{5:+-- 14 lines: 00}|
+        {1:  }{2: 17 }00000019!!!!!!!!│{1:  }{2: 19 }00000019!!!!!!!!|
+        {1:  }{2: 18 }00000020!!!!!!!!│{1:  }{2: 20 }00000020!!!!!!!!|
+        {1:  }{2:    }{3:----------------}│{1:  }{2: 21 }{4:00000025!!!!!!!!}|
+        {1:  }{2:    }{3:----------------}│{1:  }{2: 22 }{4:00000026!!!!!!!!}|
+        {1:  }{2:    }{3:----------------}│{1:  }{2: 23 }{4:00000027!!!!!!!!}|
+        {1:  }{2: 19 }00000028!!!!!!!!│{1:  }{2: 24 }^00000028!!!!!!!!|
+        {1:  }{2: 20 }00000029!!!!!!!!│{1:  }{2: 25 }00000029!!!!!!!!|
+        {1:+ }{2: 21 }{5:+-- 14 lines: 00}│{1:+ }{2: 26 }{5:+-- 14 lines: 00}|
+        {1:  }{2: 35 }00000044!!!!!!!!│{1:  }{2: 40 }00000044!!!!!!!!|
+        {1:  }{2: 36 }00000045!!!!!!!!│{1:  }{2: 41 }00000045!!!!!!!!|
+        {1:  }{2: 37 }{4:00000046!!!!!!!!}│{1:  }{2:    }{3:----------------}|
+        {1:  }{2: 38 }{4:00000047!!!!!!!!}│{1:  }{2:    }{3:----------------}|
+        {1:  }{2: 39 }{4:00000048!!!!!!!!}│{1:  }{2:    }{3:----------------}|
+        {1:  }{2: 40 }{4:00000049!!!!!!!!}│{1:  }{2:    }{3:----------------}|
+        {1:  }{2: 41 }{4:00000050!!!!!!!!}│{1:  }{2:    }{3:----------------}|
+        {8:[No Name] [+]          }{9:[No Name] [+]         }|
+                                                     |
+      ]]}
+      screen:try_resize(45, 3)
+      screen:expect{grid=[[
+        {1:  }{2: 19 }00000028!!!!!!!!│{1:  }{2: 24 }^00000028!!!!!!!!|
+        {8:[No Name] [+]          }{9:[No Name] [+]         }|
+                                                     |
+      ]]}
+      eq({ all = 20, fill = 5 }, meths.win_text_height(1000, {}))
+      eq({ all = 20, fill = 5 }, meths.win_text_height(1001, {}))
+      eq({ all = 20, fill = 5 }, meths.win_text_height(1000, { start_row = 0 }))
+      eq({ all = 20, fill = 5 }, meths.win_text_height(1001, { start_row = 0 }))
+      eq({ all = 15, fill = 0 }, meths.win_text_height(1000, { end_row = -1 }))
+      eq({ all = 15, fill = 0 }, meths.win_text_height(1000, { end_row = 40 }))
+      eq({ all = 20, fill = 5 }, meths.win_text_height(1001, { end_row = -1 }))
+      eq({ all = 20, fill = 5 }, meths.win_text_height(1001, { end_row = 40 }))
+      eq({ all = 10, fill = 5 }, meths.win_text_height(1000, { start_row = 23 }))
+      eq({ all = 13, fill = 3 }, meths.win_text_height(1001, { start_row = 18 }))
+      eq({ all = 11, fill = 0 }, meths.win_text_height(1000, { end_row = 23 }))
+      eq({ all = 11, fill = 5 }, meths.win_text_height(1001, { end_row = 18 }))
+      eq({ all = 11, fill = 0 }, meths.win_text_height(1000, { start_row = 3, end_row = 39 }))
+      eq({ all = 11, fill = 3 }, meths.win_text_height(1001, { start_row = 1, end_row = 34 }))
+      eq({ all = 9, fill = 0 }, meths.win_text_height(1000, { start_row = 4, end_row = 38 }))
+      eq({ all = 9, fill = 3 }, meths.win_text_height(1001, { start_row = 2, end_row = 33 }))
+      eq({ all = 9, fill = 0 }, meths.win_text_height(1000, { start_row = 5, end_row = 37 }))
+      eq({ all = 9, fill = 3 }, meths.win_text_height(1001, { start_row = 3, end_row = 32 }))
+      eq({ all = 9, fill = 0 }, meths.win_text_height(1000, { start_row = 17, end_row = 25 }))
+      eq({ all = 9, fill = 3 }, meths.win_text_height(1001, { start_row = 15, end_row = 20 }))
+      eq({ all = 7, fill = 0 }, meths.win_text_height(1000, { start_row = 18, end_row = 24 }))
+      eq({ all = 7, fill = 3 }, meths.win_text_height(1001, { start_row = 16, end_row = 19 }))
+      eq({ all = 6, fill = 5 }, meths.win_text_height(1000, { start_row = -1 }))
+      eq({ all = 5, fill = 5 }, meths.win_text_height(1000, { start_row = -1, start_vcol = X }))
+      eq({ all = 0, fill = 0 }, meths.win_text_height(1000, { start_row = -1, start_vcol = X, end_row = -1 }))
+      eq({ all = 0, fill = 0 }, meths.win_text_height(1000, { start_row = -1, start_vcol = X, end_row = -1, end_vcol = X }))
+      eq({ all = 1, fill = 0 }, meths.win_text_height(1000, { start_row = -1, start_vcol = 0, end_row = -1, end_vcol = X }))
+      eq({ all = 3, fill = 2 }, meths.win_text_height(1001, { end_row = 0 }))
+      eq({ all = 2, fill = 2 }, meths.win_text_height(1001, { end_row = 0, end_vcol = 0 }))
+      eq({ all = 2, fill = 2 }, meths.win_text_height(1001, { start_row = 0, end_row = 0, end_vcol = 0 }))
+      eq({ all = 0, fill = 0 }, meths.win_text_height(1001, { start_row = 0, start_vcol = 0, end_row = 0, end_vcol = 0 }))
+      eq({ all = 1, fill = 0 }, meths.win_text_height(1001, { start_row = 0, start_vcol = 0, end_row = 0, end_vcol = X }))
+      eq({ all = 11, fill = 5 }, meths.win_text_height(1001, { end_row = 18 }))
+      eq({ all = 9, fill = 3 }, meths.win_text_height(1001, { start_row = 0, start_vcol = 0, end_row = 18 }))
+      eq({ all = 10, fill = 5 }, meths.win_text_height(1001, { end_row = 18, end_vcol = 0 }))
+      eq({ all = 8, fill = 3 }, meths.win_text_height(1001, { start_row = 0, start_vcol = 0, end_row = 18, end_vcol = 0 }))
+    end)
+
+    it('with wrapped lines', function()
+      local X = meths.get_vvar('maxcol')
+      local screen = Screen.new(45, 22)
+      screen:set_default_attr_ids({
+        [0] = {foreground = Screen.colors.Blue1, bold = true};
+        [1] = {foreground = Screen.colors.Brown};
+        [2] = {background = Screen.colors.Yellow};
+      })
+      screen:attach()
+      exec([[
+        set number cpoptions+=n
+        call setline(1, repeat([repeat('foobar-', 36)], 3))
+      ]])
+      local ns = meths.create_namespace('')
+      meths.buf_set_extmark(0, ns, 1, 100, { virt_text = {{('?'):rep(15), 'Search'}}, virt_text_pos = 'inline' })
+      meths.buf_set_extmark(0, ns, 2, 200, { virt_text = {{('!'):rep(75), 'Search'}}, virt_text_pos = 'inline' })
+      screen:expect{grid=[[
+        {1:  1 }^foobar-foobar-foobar-foobar-foobar-foobar|
+        -foobar-foobar-foobar-foobar-foobar-foobar-fo|
+        obar-foobar-foobar-foobar-foobar-foobar-fooba|
+        r-foobar-foobar-foobar-foobar-foobar-foobar-f|
+        oobar-foobar-foobar-foobar-foobar-foobar-foob|
+        ar-foobar-foobar-foobar-foobar-              |
+        {1:  2 }foobar-foobar-foobar-foobar-foobar-foobar|
+        -foobar-foobar-foobar-foobar-foobar-foobar-fo|
+        obar-foobar-fo{2:???????????????}obar-foobar-foob|
+        ar-foobar-foobar-foobar-foobar-foobar-foobar-|
+        foobar-foobar-foobar-foobar-foobar-foobar-foo|
+        bar-foobar-foobar-foobar-foobar-foobar-foobar|
+        -                                            |
+        {1:  3 }foobar-foobar-foobar-foobar-foobar-foobar|
+        -foobar-foobar-foobar-foobar-foobar-foobar-fo|
+        obar-foobar-foobar-foobar-foobar-foobar-fooba|
+        r-foobar-foobar-foobar-foobar-foobar-foobar-f|
+        oobar-foobar-foobar-foob{2:!!!!!!!!!!!!!!!!!!!!!}|
+        {2:!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!}|
+        {2:!!!!!!!!!}ar-foobar-foobar-foobar-foobar-fooba|
+        r-foobar-foobar-                             |
+                                                     |
+      ]]}
+      screen:try_resize(45, 2)
+      screen:expect{grid=[[
+        {1:  1 }^foobar-foobar-foobar-foobar-foobar-foobar|
+                                                     |
+      ]]}
+      eq({ all = 21, fill = 0 }, meths.win_text_height(0, {}))
+      eq({ all = 6, fill = 0 }, meths.win_text_height(0, { start_row = 0, end_row = 0 }))
+      eq({ all = 7, fill = 0 }, meths.win_text_height(0, { start_row = 1, end_row = 1 }))
+      eq({ all = 8, fill = 0 }, meths.win_text_height(0, { start_row = 2, end_row = 2 }))
+      eq({ all = 0, fill = 0 }, meths.win_text_height(0, { start_row = 1, start_vcol = 0, end_row = 1, end_vcol = 0 }))
+      eq({ all = 1, fill = 0 }, meths.win_text_height(0, { start_row = 1, start_vcol = 0, end_row = 1, end_vcol = 41 }))
+      eq({ all = 2, fill = 0 }, meths.win_text_height(0, { start_row = 1, start_vcol = 0, end_row = 1, end_vcol = 42 }))
+      eq({ all = 2, fill = 0 }, meths.win_text_height(0, { start_row = 1, start_vcol = 0, end_row = 1, end_vcol = 86 }))
+      eq({ all = 3, fill = 0 }, meths.win_text_height(0, { start_row = 1, start_vcol = 0, end_row = 1, end_vcol = 87 }))
+      eq({ all = 6, fill = 0 }, meths.win_text_height(0, { start_row = 1, start_vcol = 0, end_row = 1, end_vcol = 266 }))
+      eq({ all = 7, fill = 0 }, meths.win_text_height(0, { start_row = 1, start_vcol = 0, end_row = 1, end_vcol = 267 }))
+      eq({ all = 7, fill = 0 }, meths.win_text_height(0, { start_row = 1, start_vcol = 0, end_row = 1, end_vcol = 311 }))
+      eq({ all = 7, fill = 0 }, meths.win_text_height(0, { start_row = 1, start_vcol = 0, end_row = 1, end_vcol = 312 }))
+      eq({ all = 7, fill = 0 }, meths.win_text_height(0, { start_row = 1, start_vcol = 0, end_row = 1, end_vcol = X }))
+      eq({ all = 7, fill = 0 }, meths.win_text_height(0, { start_row = 1, start_vcol = 40, end_row = 1, end_vcol = X }))
+      eq({ all = 6, fill = 0 }, meths.win_text_height(0, { start_row = 1, start_vcol = 41, end_row = 1, end_vcol = X }))
+      eq({ all = 6, fill = 0 }, meths.win_text_height(0, { start_row = 1, start_vcol = 85, end_row = 1, end_vcol = X }))
+      eq({ all = 5, fill = 0 }, meths.win_text_height(0, { start_row = 1, start_vcol = 86, end_row = 1, end_vcol = X }))
+      eq({ all = 2, fill = 0 }, meths.win_text_height(0, { start_row = 1, start_vcol = 265, end_row = 1, end_vcol = X }))
+      eq({ all = 1, fill = 0 }, meths.win_text_height(0, { start_row = 1, start_vcol = 266, end_row = 1, end_vcol = X }))
+      eq({ all = 1, fill = 0 }, meths.win_text_height(0, { start_row = 1, start_vcol = 310, end_row = 1, end_vcol = X }))
+      eq({ all = 0, fill = 0 }, meths.win_text_height(0, { start_row = 1, start_vcol = 311, end_row = 1, end_vcol = X }))
+      eq({ all = 1, fill = 0 }, meths.win_text_height(0, { start_row = 1, start_vcol = 86, end_row = 1, end_vcol = 131 }))
+      eq({ all = 1, fill = 0 }, meths.win_text_height(0, { start_row = 1, start_vcol = 221, end_row = 1, end_vcol = 266 }))
+      eq({ all = 18, fill = 0 }, meths.win_text_height(0, { start_row = 0, start_vcol = 131 }))
+      eq({ all = 19, fill = 0 }, meths.win_text_height(0, { start_row = 0, start_vcol = 130 }))
+      eq({ all = 20, fill = 0 }, meths.win_text_height(0, { end_row = 2, end_vcol = 311 }))
+      eq({ all = 21, fill = 0 }, meths.win_text_height(0, { end_row = 2, end_vcol = 312 }))
+      eq({ all = 17, fill = 0 }, meths.win_text_height(0, { start_row = 0, start_vcol = 131, end_row = 2, end_vcol = 311 }))
+      eq({ all = 19, fill = 0 }, meths.win_text_height(0, { start_row = 0, start_vcol = 130, end_row = 2, end_vcol = 312 }))
+      eq({ all = 16, fill = 0 }, meths.win_text_height(0, { start_row = 0, start_vcol = 221 }))
+      eq({ all = 17, fill = 0 }, meths.win_text_height(0, { start_row = 0, start_vcol = 220 }))
+      eq({ all = 14, fill = 0 }, meths.win_text_height(0, { end_row = 2, end_vcol = 41 }))
+      eq({ all = 15, fill = 0 }, meths.win_text_height(0, { end_row = 2, end_vcol = 42 }))
+      eq({ all = 9, fill = 0 }, meths.win_text_height(0, { start_row = 0, start_vcol = 221, end_row = 2, end_vcol = 41 }))
+      eq({ all = 11, fill = 0 }, meths.win_text_height(0, { start_row = 0, start_vcol = 220, end_row = 2, end_vcol = 42 }))
+    end)
   end)
 
   describe('open_win', function()
@@ -591,19 +864,45 @@ describe('API/win', function()
       })
       eq(1, funcs.exists('g:fired'))
     end)
+
+    it('disallowed in cmdwin if enter=true or buf=curbuf', function()
+      local new_buf = meths.create_buf(true, true)
+      feed('q:')
+      eq('E11: Invalid in command-line window; <CR> executes, CTRL-C quits',
+         pcall_err(meths.open_win, new_buf, true, {
+           relative='editor', row=5, col=5, width=5, height=5,
+         }))
+      eq('E11: Invalid in command-line window; <CR> executes, CTRL-C quits',
+         pcall_err(meths.open_win, 0, false, {
+           relative='editor', row=5, col=5, width=5, height=5,
+         }))
+
+      eq(new_buf, meths.win_get_buf(meths.open_win(new_buf, false, {
+           relative='editor', row=5, col=5, width=5, height=5,
+         })))
+    end)
+
+    it('aborts if buffer is invalid', function()
+      local wins_before = meths.list_wins()
+      eq('Invalid buffer id: 1337', pcall_err(meths.open_win, 1337, false, {
+           relative='editor', row=5, col=5, width=5, height=5,
+         }))
+      eq(wins_before, meths.list_wins())
+    end)
   end)
 
   describe('get_config', function()
     it('includes border', function()
       local b = { 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h' }
       local win = meths.open_win(0, true, {
-         relative='win', row=3, col=3, width=12, height=3,
-         border = b,
+        relative='win', row=3, col=3, width=12, height=3,
+        border = b,
       })
 
       local cfg = meths.win_get_config(win)
       eq(b, cfg.border)
     end)
+
     it('includes border with highlight group', function()
       local b = {
         {'a', 'Normal'},
@@ -616,12 +915,25 @@ describe('API/win', function()
         {'h', 'PreProc'},
       }
       local win = meths.open_win(0, true, {
-         relative='win', row=3, col=3, width=12, height=3,
-         border = b,
+        relative='win', row=3, col=3, width=12, height=3,
+        border = b,
       })
 
       local cfg = meths.win_get_config(win)
       eq(b, cfg.border)
     end)
+
+    it('includes title and footer', function()
+      local title = { {'A', {'StatusLine', 'TabLine'}}, {'B'}, {'C', 'WinBar'} }
+      local footer = { {'A', 'WinBar'}, {'B'}, {'C', {'StatusLine', 'TabLine'}} }
+      local win = meths.open_win(0, true, {
+        relative='win', row=3, col=3, width=12, height=3,
+        border = 'single', title = title, footer = footer,
+      })
+
+      local cfg = meths.win_get_config(win)
+      eq(title, cfg.title)
+      eq(footer, cfg.footer)
+    end)
   end)
 end)