Merge remote-tracking branch 'upstream/master' into mix_20240309

16 files changed, 560 insertions, 114 deletions

diff --git a/test/functional/lua/buffer_updates_spec.lua b/test/functional/lua/buffer_updates_spec.lua
index f277868b1c..7d034222c8 100644
--- a/test/functional/lua/buffer_updates_spec.lua
+++ b/test/functional/lua/buffer_updates_spec.lua
@@ -344,7 +344,6 @@ describe('lua buffer event callbacks: on_lines', function()
 
   it('setting extmark in on_lines callback works', function()
     local screen = Screen.new(40, 6)
-    screen:attach()
 
     api.nvim_buf_set_lines(0, 0, -1, true, { 'aaa', 'bbb', 'ccc' })
     exec_lua(function()
diff --git a/test/functional/lua/commands_spec.lua b/test/functional/lua/commands_spec.lua
index 456ee13da2..1fd01cfd5a 100644
--- a/test/functional/lua/commands_spec.lua
+++ b/test/functional/lua/commands_spec.lua
@@ -111,7 +111,6 @@ describe(':lua', function()
 
   it('can show multiline error messages', function()
     local screen = Screen.new(40, 10)
-    screen:attach()
     screen:set_default_attr_ids({
       [1] = { bold = true, foreground = Screen.colors.Blue1 },
       [2] = { bold = true, reverse = true },
@@ -204,7 +203,6 @@ describe(':lua', function()
 
   it('with range', function()
     local screen = Screen.new(40, 10)
-    screen:attach()
     api.nvim_buf_set_lines(0, 0, 0, 0, { 'nonsense', 'function x() print "hello" end', 'x()' })
 
     -- ":{range}lua" fails on invalid Lua code.
diff --git a/test/functional/lua/diagnostic_spec.lua b/test/functional/lua/diagnostic_spec.lua
index 4ae1146703..eb1ac3e6a1 100644
--- a/test/functional/lua/diagnostic_spec.lua
+++ b/test/functional/lua/diagnostic_spec.lua
@@ -111,6 +111,19 @@ describe('vim.diagnostic', function()
           { details = true }
         )
       end
+
+      ---@param ns integer
+      function _G.get_underline_extmarks(ns)
+        ---@type integer
+        local underline_ns = vim.diagnostic.get_namespace(ns).user_data.underline_ns
+        return vim.api.nvim_buf_get_extmarks(
+          _G.diagnostic_bufnr,
+          underline_ns,
+          0,
+          -1,
+          { details = true }
+        )
+      end
     end)
 
     exec_lua(function()
@@ -1813,6 +1826,21 @@ describe('vim.diagnostic', function()
           _G.make_info('Info', 4, 4, 4, 4),
         })
 
+        function _G.get_highest_underline_hl(severity_sort)
+          vim.diagnostic.config({
+            underline = true,
+            severity_sort = severity_sort,
+          })
+
+          local extmarks = _G.get_underline_extmarks(_G.diagnostic_ns)
+
+          table.sort(extmarks, function(a, b)
+            return a[4].priority > b[4].priority
+          end)
+
+          return extmarks[1][4].hl_group
+        end
+
         function _G.get_virt_text_and_signs(severity_sort)
           vim.diagnostic.config({
             severity_sort = severity_sort,
@@ -1864,6 +1892,12 @@ describe('vim.diagnostic', function()
       result = exec_lua [[return _G.get_virt_text_and_signs({ reverse = true })]]
       eq({ 'Error', 'Warn', 'Info' }, result[1])
       eq({ 'Info', 'Warn', 'Error' }, result[2])
+
+      local underline_hl = exec_lua [[return _G.get_highest_underline_hl(true)]]
+      eq('DiagnosticUnderlineError', underline_hl)
+
+      underline_hl = exec_lua [[return _G.get_highest_underline_hl({ reverse = true })]]
+      eq('DiagnosticUnderlineInfo', underline_hl)
     end)
 
     it('can show diagnostic sources in virtual text', function()
diff --git a/test/functional/lua/filetype_spec.lua b/test/functional/lua/filetype_spec.lua
index 574c837f92..b6011d5268 100644
--- a/test/functional/lua/filetype_spec.lua
+++ b/test/functional/lua/filetype_spec.lua
@@ -161,6 +161,18 @@ describe('vim.filetype', function()
       end
     end
   end)
+
+  it('.get_option() cleans up buffer on error', function()
+    api.nvim_create_autocmd('FileType', { pattern = 'foo', command = 'lua error()' })
+
+    local buf = api.nvim_get_current_buf()
+
+    exec_lua(function()
+      pcall(vim.filetype.get_option, 'foo', 'lisp')
+    end)
+
+    eq(buf, api.nvim_get_current_buf())
+  end)
 end)
 
 describe('filetype.lua', function()
diff --git a/test/functional/lua/highlight_spec.lua b/test/functional/lua/hl_spec.lua
index c048949df8..89881973bf 100644
--- a/test/functional/lua/highlight_spec.lua
+++ b/test/functional/lua/hl_spec.lua
@@ -9,7 +9,7 @@ local command = n.command
 local clear = n.clear
 local api = n.api
 
-describe('vim.highlight.range', function()
+describe('vim.hl.range', function()
   local screen
 
   before_each(function()
@@ -18,7 +18,6 @@ describe('vim.highlight.range', function()
     screen:add_extra_attr_ids({
       [100] = { foreground = Screen.colors.Blue, background = Screen.colors.Yellow, bold = true },
     })
-    screen:attach()
     api.nvim_set_option_value('list', true, {})
     api.nvim_set_option_value('listchars', 'eol:$', {})
     api.nvim_buf_set_lines(0, 0, -1, true, {
@@ -33,7 +32,7 @@ describe('vim.highlight.range', function()
   it('works with charwise selection', function()
     exec_lua(function()
       local ns = vim.api.nvim_create_namespace('')
-      vim.highlight.range(0, ns, 'Search', { 1, 5 }, { 3, 10 })
+      vim.hl.range(0, ns, 'Search', { 1, 5 }, { 3, 10 })
     end)
     screen:expect([[
       ^asdfghjkl{1:$}                                                  |
@@ -48,7 +47,7 @@ describe('vim.highlight.range', function()
   it('works with linewise selection', function()
     exec_lua(function()
       local ns = vim.api.nvim_create_namespace('')
-      vim.highlight.range(0, ns, 'Search', { 0, 0 }, { 4, 0 }, { regtype = 'V' })
+      vim.hl.range(0, ns, 'Search', { 0, 0 }, { 4, 0 }, { regtype = 'V' })
     end)
     screen:expect([[
       {10:^asdfghjkl}{100:$}                                                  |
@@ -63,7 +62,7 @@ describe('vim.highlight.range', function()
   it('works with blockwise selection', function()
     exec_lua(function()
       local ns = vim.api.nvim_create_namespace('')
-      vim.highlight.range(0, ns, 'Search', { 0, 0 }, { 4, 4 }, { regtype = '\022' })
+      vim.hl.range(0, ns, 'Search', { 0, 0 }, { 4, 4 }, { regtype = '\022' })
     end)
     screen:expect([[
       {10:^asdf}ghjkl{1:$}                                                  |
@@ -78,7 +77,7 @@ describe('vim.highlight.range', function()
   it('works with blockwise selection with width', function()
     exec_lua(function()
       local ns = vim.api.nvim_create_namespace('')
-      vim.highlight.range(0, ns, 'Search', { 0, 4 }, { 4, 7 }, { regtype = '\0226' })
+      vim.hl.range(0, ns, 'Search', { 0, 4 }, { 4, 7 }, { regtype = '\0226' })
     end)
     screen:expect([[
       ^asdf{10:ghjkl}{1:$}                                                  |
@@ -93,8 +92,8 @@ describe('vim.highlight.range', function()
   it('can use -1 or v:maxcol to indicate end of line', function()
     exec_lua(function()
       local ns = vim.api.nvim_create_namespace('')
-      vim.highlight.range(0, ns, 'Search', { 0, 4 }, { 1, -1 }, {})
-      vim.highlight.range(0, ns, 'Search', { 2, 6 }, { 3, vim.v.maxcol }, {})
+      vim.hl.range(0, ns, 'Search', { 0, 4 }, { 1, -1 }, {})
+      vim.hl.range(0, ns, 'Search', { 2, 6 }, { 3, vim.v.maxcol }, {})
     end)
     screen:expect([[
       ^asdf{10:ghjkl}{100:$}                                                  |
@@ -107,7 +106,7 @@ describe('vim.highlight.range', function()
   end)
 end)
 
-describe('vim.highlight.on_yank', function()
+describe('vim.hl.on_yank', function()
   before_each(function()
     clear()
   end)
@@ -115,7 +114,7 @@ describe('vim.highlight.on_yank', function()
   it('does not show errors even if buffer is wiped before timeout', function()
     command('new')
     exec_lua(function()
-      vim.highlight.on_yank({
+      vim.hl.on_yank({
         timeout = 10,
         on_macro = true,
         event = { operator = 'y', regtype = 'v' },
@@ -129,10 +128,10 @@ describe('vim.highlight.on_yank', function()
 
   it('does not close timer twice', function()
     exec_lua(function()
-      vim.highlight.on_yank({ timeout = 10, on_macro = true, event = { operator = 'y' } })
+      vim.hl.on_yank({ timeout = 10, on_macro = true, event = { operator = 'y' } })
       vim.uv.sleep(10)
       vim.schedule(function()
-        vim.highlight.on_yank({ timeout = 0, on_macro = true, event = { operator = 'y' } })
+        vim.hl.on_yank({ timeout = 0, on_macro = true, event = { operator = 'y' } })
       end)
     end)
     eq('', eval('v:errmsg'))
@@ -143,7 +142,7 @@ describe('vim.highlight.on_yank', function()
     exec_lua(function()
       vim.api.nvim_buf_set_mark(0, '[', 1, 1, {})
       vim.api.nvim_buf_set_mark(0, ']', 1, 1, {})
-      vim.highlight.on_yank({ timeout = math.huge, on_macro = true, event = { operator = 'y' } })
+      vim.hl.on_yank({ timeout = math.huge, on_macro = true, event = { operator = 'y' } })
     end)
     local ns = api.nvim_create_namespace('hlyank')
     local win = api.nvim_get_current_win()
@@ -157,7 +156,7 @@ describe('vim.highlight.on_yank', function()
     exec_lua(function()
       vim.api.nvim_buf_set_mark(0, '[', 1, 1, {})
       vim.api.nvim_buf_set_mark(0, ']', 1, 1, {})
-      vim.highlight.on_yank({ timeout = math.huge, on_macro = true, event = { operator = 'y' } })
+      vim.hl.on_yank({ timeout = math.huge, on_macro = true, event = { operator = 'y' } })
     end)
     local ns = api.nvim_create_namespace('hlyank')
     eq(api.nvim_get_current_win(), api.nvim__ns_get(ns).wins[1])
@@ -165,7 +164,7 @@ describe('vim.highlight.on_yank', function()
     exec_lua(function()
       vim.api.nvim_buf_set_mark(0, '[', 1, 1, {})
       vim.api.nvim_buf_set_mark(0, ']', 1, 1, {})
-      vim.highlight.on_yank({ timeout = math.huge, on_macro = true, event = { operator = 'y' } })
+      vim.hl.on_yank({ timeout = math.huge, on_macro = true, event = { operator = 'y' } })
     end)
     local win = api.nvim_get_current_win()
     eq({ win }, api.nvim__ns_get(ns).wins)
diff --git a/test/functional/lua/loop_spec.lua b/test/functional/lua/loop_spec.lua
index de8200a5f1..52a8fec0bf 100644
--- a/test/functional/lua/loop_spec.lua
+++ b/test/functional/lua/loop_spec.lua
@@ -65,7 +65,6 @@ describe('vim.uv', function()
 
   it('is API safe', function()
     local screen = Screen.new(50, 10)
-    screen:attach()
     screen:set_default_attr_ids({
       [1] = { bold = true, foreground = Screen.colors.Blue1 },
       [2] = { bold = true, reverse = true },
@@ -88,9 +87,9 @@ describe('vim.uv', function()
     screen:expect([[
                                                         |
       {2:                                                  }|
-      {3:Error executing luv callback:}                     |
+      {3:Error executing callback:}                         |
       {3:[string "<nvim>"]:5: E5560: nvim_set_var must not }|
-      {3:be called in a lua loop callback}                  |
+      {3:be called in a fast event context}                 |
       {3:stack traceback:}                                  |
       {3:        [C]: in function 'nvim_set_var'}           |
       {3:        [string "<nvim>"]:5: in function <[string }|
diff --git a/test/functional/lua/luaeval_spec.lua b/test/functional/lua/luaeval_spec.lua
index 2b23f72c7d..5fea79141c 100644
--- a/test/functional/lua/luaeval_spec.lua
+++ b/test/functional/lua/luaeval_spec.lua
@@ -510,7 +510,6 @@ describe('v:lua', function()
 
   it('works in func options', function()
     local screen = Screen.new(60, 8)
-    screen:attach()
     api.nvim_set_option_value('omnifunc', 'v:lua.mymod.omni', {})
     feed('isome st<c-x><c-o>')
     screen:expect{grid=[[
diff --git a/test/functional/lua/overrides_spec.lua b/test/functional/lua/overrides_spec.lua
index 33a2813200..2f332d2c10 100644
--- a/test/functional/lua/overrides_spec.lua
+++ b/test/functional/lua/overrides_spec.lua
@@ -158,7 +158,6 @@ describe('print', function()
 
   it('blank line in message works', function()
     local 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 },
@@ -196,7 +195,6 @@ describe('debug.debug', function()
 
   before_each(function()
     screen = Screen.new()
-    screen:attach()
     screen:set_default_attr_ids {
       [0] = { bold = true, foreground = 255 },
       [1] = { bold = true, reverse = true },
diff --git a/test/functional/lua/runtime_spec.lua b/test/functional/lua/runtime_spec.lua
index f63363d6d9..6705dff847 100644
--- a/test/functional/lua/runtime_spec.lua
+++ b/test/functional/lua/runtime_spec.lua
@@ -21,7 +21,9 @@ describe('runtime:', function()
     exec('set rtp+=' .. plug_dir)
     exec([[
       set shell=doesnotexist
-      set completeslash=slash
+      if exists('+completeslash')
+        set completeslash=slash
+      endif
       set isfname+=(,)
     ]])
   end)
diff --git a/test/functional/lua/secure_spec.lua b/test/functional/lua/secure_spec.lua
index c58fd689b7..b40b084ef9 100644
--- a/test/functional/lua/secure_spec.lua
+++ b/test/functional/lua/secure_spec.lua
@@ -39,7 +39,6 @@ describe('vim.secure', function()
 
     it('works', function()
       local screen = Screen.new(80, 8)
-      screen:attach()
       screen:set_default_attr_ids({
         [1] = { bold = true, foreground = Screen.colors.Blue1 },
         [2] = { bold = true, reverse = true },
diff --git a/test/functional/lua/system_spec.lua b/test/functional/lua/system_spec.lua
index 482bfcf1a9..afbada007d 100644
--- a/test/functional/lua/system_spec.lua
+++ b/test/functional/lua/system_spec.lua
@@ -9,7 +9,7 @@ local function system_sync(cmd, opts)
   return exec_lua(function()
     local obj = vim.system(cmd, opts)
 
-    if opts.timeout then
+    if opts and opts.timeout then
       -- Minor delay before calling wait() so the timeout uv timer can have a headstart over the
       -- internal call to vim.wait() in wait().
       vim.wait(10)
@@ -75,7 +75,7 @@ describe('vim.system', function()
 
   it('kill processes', function()
     exec_lua(function()
-      local signal
+      local signal --- @type integer?
       local cmd = vim.system({ 'cat', '-' }, { stdin = true }, function(r)
         signal = r.signal
       end) -- run forever
@@ -112,4 +112,12 @@ describe('vim.system', function()
     )
     eq(true, exec_lua([[return _G.processed]]))
   end)
+
+  if t.is_os('win') then
+    it('can resolve windows command extentions.', function()
+      t.write_file('test.bat', 'echo hello world')
+      system_sync({ 'chmod', '+x', 'test.bat' })
+      system_sync({ './test' })
+    end)
+  end
 end)
diff --git a/test/functional/lua/thread_spec.lua b/test/functional/lua/thread_spec.lua
index cbf23517dc..310705fd97 100644
--- a/test/functional/lua/thread_spec.lua
+++ b/test/functional/lua/thread_spec.lua
@@ -17,7 +17,6 @@ describe('thread', function()
   before_each(function()
     clear()
     screen = Screen.new(50, 10)
-    screen:attach()
   end)
 
   it('entry func is executed in protected mode', function()
@@ -257,7 +256,6 @@ describe('threadpool', function()
 
   it('with invalid return value', function()
     local screen = Screen.new(50, 10)
-    screen:attach()
 
     exec_lua [[
       local work = vim.uv.new_work(function() return {} end, function() end)
diff --git a/test/functional/lua/ui_event_spec.lua b/test/functional/lua/ui_event_spec.lua
index 0a6deaa41c..c8616e3e11 100644
--- a/test/functional/lua/ui_event_spec.lua
+++ b/test/functional/lua/ui_event_spec.lua
@@ -32,16 +32,6 @@ describe('vim.ui_attach', function()
     ]]
 
     screen = Screen.new(40, 5)
-    screen:set_default_attr_ids({
-      [1] = { bold = true, foreground = Screen.colors.Blue1 },
-      [2] = { bold = true },
-      [3] = { background = Screen.colors.Grey },
-      [4] = { background = Screen.colors.LightMagenta },
-      [5] = { reverse = true },
-      [6] = { reverse = true, bold = true },
-      [7] = { background = Screen.colors.Yellow1 },
-    })
-    screen:attach()
   end)
 
   local function expect_events(expected)
@@ -56,7 +46,7 @@ describe('vim.ui_attach', function()
       grid = [[
       fo^                                      |
       {1:~                                       }|*3
-      {2:-- INSERT --}                            |
+      {5:-- INSERT --}                            |
     ]],
     }
 
@@ -65,7 +55,7 @@ describe('vim.ui_attach', function()
       grid = [[
       food^                                    |
       {1:~                                       }|*3
-      {2:-- INSERT --}                            |
+      {5:-- INSERT --}                            |
     ]],
     }
     expect_events {
@@ -84,7 +74,7 @@ describe('vim.ui_attach', function()
       grid = [[
       foobar^                                  |
       {1:~                                       }|*3
-      {2:-- INSERT --}                            |
+      {5:-- INSERT --}                            |
     ]],
     }
     expect_events {
@@ -106,10 +96,10 @@ describe('vim.ui_attach', function()
     screen:expect {
       grid = [[
       food^                                    |
-      {3:food           }{1:                         }|
+      {12:food           }{1:                         }|
       {4:foobar         }{1:                         }|
       {4:foo            }{1:                         }|
-      {2:-- INSERT --}                            |
+      {5:-- INSERT --}                            |
     ]],
     }
     expect_events {}
@@ -151,9 +141,9 @@ describe('vim.ui_attach', function()
       {
         'msg_history_show',
         {
-          { 'echomsg', { { 0, 'message1' } } },
-          { '', { { 0, 'message2' } } },
-          { 'echomsg', { { 0, 'message3' } } },
+          { 'echomsg', { { 0, 'message1', 0 } } },
+          { 'lua_print', { { 0, 'message2', 0 } } },
+          { 'echomsg', { { 0, 'message3', 0 } } },
         },
       },
     }, actual, vim.inspect(actual))
@@ -181,12 +171,17 @@ describe('vim.ui_attach', function()
     exec_lua([[
       _G.cmdline = 0
       vim.ui_attach(ns, { ext_messages = true }, function(ev)
-        vim.cmd.redraw()
+        if ev == 'msg_show' then
+          vim.schedule(function() vim.cmd.redraw() end)
+        else
+          vim.cmd.redraw()
+        end
         _G.cmdline = _G.cmdline + (ev == 'cmdline_show' and 1 or 0)
       end
     )]])
     feed(':')
-    eq(1, exec_lua('return _G.cmdline'))
+    n.assert_alive()
+    eq(2, exec_lua('return _G.cmdline'))
     n.assert_alive()
     feed('version<CR><CR>v<Esc>')
     n.assert_alive()
@@ -212,9 +207,9 @@ describe('vim.ui_attach', function()
     screen:expect({
       grid = [[
         cmdline                                 |
-        {5:cmdline [+]                             }|
+        {2:cmdline [+]                             }|
         fooba^r                                  |
-        {6:[No Name] [+]                           }|
+        {3:[No Name] [+]                           }|
                                                 |
       ]],
     })
@@ -223,9 +218,9 @@ describe('vim.ui_attach', function()
     screen:expect({
       grid = [[
         foo                                     |
-        {5:cmdline [+]                             }|
-        {5:foo}ba^r                                  |
-        {6:[No Name] [+]                           }|
+        {2:cmdline [+]                             }|
+        {2:foo}ba^r                                  |
+        {3:[No Name] [+]                           }|
                                                 |
       ]],
     })
@@ -234,25 +229,78 @@ describe('vim.ui_attach', function()
     screen:expect({
       grid = [[
         %s/bar/baz                              |
-        {5:cmdline [+]                             }|
-        foo{7:ba^z}                                  |
-        {6:[No Name] [+]                           }|
+        {2:cmdline [+]                             }|
+        foo{10:ba^z}                                  |
+        {3:[No Name] [+]                           }|
                                                 |
       ]],
     })
   end)
+
+  it('msg_show in fast context', function()
+    exec_lua([[
+    vim.ui_attach(ns, { ext_messages = true }, function(event, _, content)
+      if event == "msg_show" then
+        vim.api.nvim_get_runtime_file("foo", false)
+        -- non-"fast-api" is not allowed in msg_show callback and should be scheduled
+        local _, err = pcall(vim.api.nvim_buf_set_lines, 0, -2, -1, false, { content[1][2] })
+        pcall(vim.api.nvim__redraw, { flush = true })
+        vim.schedule(function()
+          vim.api.nvim_buf_set_lines(0, -2, -1, false, { content[1][2], err })
+        end)
+      end
+    end)
+    ]])
+    -- "fast-api" does not prevent aborting :function
+    feed(':func Foo()<cr>bar<cr>endf<cr>:func Foo()<cr>')
+    screen:expect({
+      grid = [[
+        ^E122: Function Foo already exists, add !|
+         to replace it                          |
+        E5560: nvim_buf_set_lines must not be ca|
+        lled in a fast event context            |
+        {1:~                                       }|
+      ]],
+      messages = {
+        {
+          content = { { 'E122: Function Foo already exists, add ! to replace it', 9, 7 } },
+          kind = 'emsg',
+        },
+      },
+    })
+    -- No fast context for prompt message kinds
+    feed(':%s/Function/Replacement/c<cr>')
+    screen:expect({
+      grid = [[
+        ^E122: {10:Function} Foo already exists, add !|
+         to replace it                          |
+        replace with Replacement (y/n/a/q/l/^E/^|
+        Y)?                                     |
+        {1:~                                       }|
+      ]],
+      messages = {
+        {
+          content = { { 'replace with Replacement (y/n/a/q/l/^E/^Y)?', 6, 19 } },
+          kind = 'confirm_sub',
+        },
+      },
+    })
+  end)
 end)
 
 describe('vim.ui_attach', function()
+  local screen
+  before_each(function()
+    clear({ env = { NVIM_LOG_FILE = testlog } })
+    screen = Screen.new(40, 5)
+  end)
+
   after_each(function()
     check_close()
     os.remove(testlog)
   end)
 
   it('error in callback is logged', function()
-    clear({ env = { NVIM_LOG_FILE = testlog } })
-    local screen = Screen.new()
-    screen:attach()
     exec_lua([[
       local ns = vim.api.nvim_create_namespace('testspace')
       vim.ui_attach(ns, { ext_popupmenu = true }, function() error(42) end)
@@ -260,4 +308,83 @@ describe('vim.ui_attach', function()
     feed('ifoo<CR>foobar<CR>fo<C-X><C-N>')
     assert_log('Error executing UI event callback: Error executing lua: .*: 42', testlog, 100)
   end)
+
+  it('detaches after excessive errors', function()
+    screen:add_extra_attr_ids({ [100] = { bold = true, foreground = Screen.colors.SeaGreen } })
+    exec_lua([[
+      vim.ui_attach(vim.api.nvim_create_namespace(''), { ext_messages = true }, function()
+        vim.api.nvim_buf_set_lines(0, -2, -1, false, { err[1] })
+      end)
+    ]])
+    screen:expect({
+      grid = [[
+        ^                                        |
+        {1:~                                       }|*4
+      ]],
+    })
+    feed('ifoo')
+    screen:expect({
+      grid = [[
+        foo^                                     |
+        {1:~                                       }|*4
+      ]],
+      showmode = { { '-- INSERT --', 5, 12 } },
+    })
+    feed('<esc>:1mes clear<cr>:mes<cr>')
+    screen:expect({
+      grid = [[
+        foo                                     |
+        {3:                                        }|
+        {9:Excessive errors in vim.ui_attach() call}|
+        {9:back from ns: 1.}                        |
+        {100:Press ENTER or type command to continue}^ |
+      ]],
+    })
+    feed('<cr>')
+    -- Also when scheduled
+    exec_lua([[
+      vim.ui_attach(vim.api.nvim_create_namespace(''), { ext_messages = true }, function()
+        vim.schedule(function() vim.api.nvim_buf_set_lines(0, -2, -1, false, { err[1] }) end)
+      end)
+    ]])
+    screen:expect({
+      any = 'fo^o',
+      messages = {
+        {
+          content = {
+            {
+              'Error executing vim.schedule lua callback: [string "<nvim>"]:2: attempt to index global \'err\' (a nil value)\nstack traceback:\n\t[string "<nvim>"]:2: in function <[string "<nvim>"]:2>',
+              9,
+              7,
+            },
+          },
+          kind = 'lua_error',
+        },
+        {
+          content = {
+            {
+              'Error executing vim.schedule lua callback: [string "<nvim>"]:2: attempt to index global \'err\' (a nil value)\nstack traceback:\n\t[string "<nvim>"]:2: in function <[string "<nvim>"]:2>',
+              9,
+              7,
+            },
+          },
+          kind = 'lua_error',
+        },
+        {
+          content = { { 'Press ENTER or type command to continue', 100, 19 } },
+          kind = 'return_prompt',
+        },
+      },
+    })
+    feed('<esc>:1mes clear<cr>:mes<cr>')
+    screen:expect({
+      grid = [[
+        foo                                     |
+        {3:                                        }|
+        {9:Excessive errors in vim.ui_attach() call}|
+        {9:back from ns: 2.}                        |
+        {100:Press ENTER or type command to continue}^ |
+      ]],
+    })
+  end)
 end)
diff --git a/test/functional/lua/ui_spec.lua b/test/functional/lua/ui_spec.lua
index d5eede2885..5c727b3347 100644
--- a/test/functional/lua/ui_spec.lua
+++ b/test/functional/lua/ui_spec.lua
@@ -153,7 +153,7 @@ describe('vim.ui', function()
         vim.fn.executable = function() return 0 end
       ]]
       eq(
-        'vim.ui.open: no handler found (tried: wslview, explorer.exe, xdg-open)',
+        'vim.ui.open: no handler found (tried: wslview, explorer.exe, xdg-open, lemonade)',
         exec_lua [[local _, err = vim.ui.open('foo') ; return err]]
       )
     end)
diff --git a/test/functional/lua/vim_spec.lua b/test/functional/lua/vim_spec.lua
index 3c65ec664e..3cfbfe167a 100644
--- a/test/functional/lua/vim_spec.lua
+++ b/test/functional/lua/vim_spec.lua
@@ -28,6 +28,7 @@ local rmdir = n.rmdir
 local write_file = t.write_file
 local poke_eventloop = n.poke_eventloop
 local assert_alive = n.assert_alive
+local expect = n.expect
 
 describe('lua stdlib', function()
   before_each(clear)
@@ -155,10 +156,10 @@ describe('lua stdlib', function()
       end)
 
       it('plugin=nil, no error if soft-deprecated', function()
-        eq(
-          vim.NIL,
-          exec_lua('return vim.deprecate(...)', 'foo.baz()', 'foo.better_baz()', '0.99.0')
-        )
+        eq(vim.NIL, exec_lua [[return vim.deprecate('old1', 'new1', '0.99.0')]])
+        -- Major version > current Nvim major is always "soft-deprecated".
+        -- XXX: This is also a reminder to update the hardcoded `nvim_major`, when Nvim reaches 1.0.
+        eq(vim.NIL, exec_lua [[return vim.deprecate('old2', 'new2', '1.0.0')]])
       end)
 
       it('plugin=nil, show error if hard-deprecated', function()
@@ -175,13 +176,6 @@ describe('lua stdlib', function()
         )
       end)
 
-      it('plugin=nil, to be deleted in the next major version (1.0)', function()
-        eq(
-          [[foo.baz() is deprecated. Run ":checkhealth vim.deprecated" for more information]],
-          exec_lua [[ return vim.deprecate('foo.baz()', nil, '1.0') ]]
-        )
-      end)
-
       it('plugin specified', function()
         -- When `plugin` is specified, don't show ":help deprecated". #22235
         eq(
@@ -319,21 +313,106 @@ describe('lua stdlib', function()
       49,
       51,
     }
+    local indices8 = {
+      [0] = 0,
+      1,
+      2,
+      3,
+      4,
+      5,
+      6,
+      7,
+      8,
+      9,
+      10,
+      11,
+      12,
+      13,
+      14,
+      15,
+      16,
+      17,
+      18,
+      19,
+      20,
+      21,
+      22,
+      23,
+      24,
+      25,
+      26,
+      27,
+      28,
+      29,
+      30,
+      31,
+      32,
+      33,
+      34,
+      35,
+      36,
+      37,
+      38,
+      39,
+      40,
+      41,
+      42,
+      43,
+      44,
+      45,
+      46,
+      47,
+      48,
+      49,
+      50,
+      51,
+    }
     for i, k in pairs(indices32) do
       eq(k, exec_lua('return vim.str_byteindex(_G.test_text, ...)', i), i)
+      eq(k, exec_lua('return vim.str_byteindex(_G.test_text, ..., false)', i), i)
+      eq(k, exec_lua('return vim.str_byteindex(_G.test_text, "utf-32", ...)', i), i)
     end
     for i, k in pairs(indices16) do
       eq(k, exec_lua('return vim.str_byteindex(_G.test_text, ..., true)', i), i)
+      eq(k, exec_lua('return vim.str_byteindex(_G.test_text, "utf-16", ...)', i), i)
     end
-    eq(
+    for i, k in pairs(indices8) do
+      eq(k, exec_lua('return vim.str_byteindex(_G.test_text, "utf-8", ...)', i), i)
+    end
+    matches(
       'index out of range',
       pcall_err(exec_lua, 'return vim.str_byteindex(_G.test_text, ...)', #indices32 + 1)
     )
-    eq(
+    matches(
       'index out of range',
       pcall_err(exec_lua, 'return vim.str_byteindex(_G.test_text, ..., true)', #indices16 + 1)
     )
-    local i32, i16 = 0, 0
+    matches(
+      'index out of range',
+      pcall_err(exec_lua, 'return vim.str_byteindex(_G.test_text, "utf-16", ...)', #indices16 + 1)
+    )
+    matches(
+      'index out of range',
+      pcall_err(exec_lua, 'return vim.str_byteindex(_G.test_text, "utf-32", ...)', #indices32 + 1)
+    )
+    matches(
+      'invalid encoding',
+      pcall_err(exec_lua, 'return vim.str_byteindex("hello", "madeupencoding", 1)')
+    )
+    eq(
+      indices32[#indices32],
+      exec_lua('return vim.str_byteindex(_G.test_text, "utf-32", 99999, false)')
+    )
+    eq(
+      indices16[#indices16],
+      exec_lua('return vim.str_byteindex(_G.test_text, "utf-16", 99999, false)')
+    )
+    eq(
+      indices8[#indices8],
+      exec_lua('return vim.str_byteindex(_G.test_text, "utf-8", 99999, false)')
+    )
+    eq(2, exec_lua('return vim.str_byteindex("é", "utf-16", 2, false)'))
+    local i32, i16, i8 = 0, 0, 0
     local len = 51
     for k = 0, len do
       if indices32[i32] < k then
@@ -345,9 +424,29 @@ describe('lua stdlib', function()
           i16 = i16 + 1
         end
       end
+      if indices8[i8] < k then
+        i8 = i8 + 1
+      end
       eq({ i32, i16 }, exec_lua('return {vim.str_utfindex(_G.test_text, ...)}', k), k)
+      eq({ i32 }, exec_lua('return {vim.str_utfindex(_G.test_text, "utf-32", ...)}', k), k)
+      eq({ i16 }, exec_lua('return {vim.str_utfindex(_G.test_text, "utf-16", ...)}', k), k)
+      eq({ i8 }, exec_lua('return {vim.str_utfindex(_G.test_text, "utf-8", ...)}', k), k)
     end
-    eq(
+
+    eq({ #indices32, #indices16 }, exec_lua('return {vim.str_utfindex(_G.test_text)}'))
+
+    eq(#indices32, exec_lua('return vim.str_utfindex(_G.test_text, "utf-32", math.huge, false)'))
+    eq(#indices16, exec_lua('return vim.str_utfindex(_G.test_text, "utf-16", math.huge, false)'))
+    eq(#indices8, exec_lua('return vim.str_utfindex(_G.test_text, "utf-8", math.huge, false)'))
+
+    eq(#indices32, exec_lua('return vim.str_utfindex(_G.test_text, "utf-32")'))
+    eq(#indices16, exec_lua('return vim.str_utfindex(_G.test_text, "utf-16")'))
+    eq(#indices8, exec_lua('return vim.str_utfindex(_G.test_text, "utf-8")'))
+    matches(
+      'invalid encoding',
+      pcall_err(exec_lua, 'return vim.str_utfindex(_G.test_text, "madeupencoding", ...)', 1)
+    )
+    matches(
       'index out of range',
       pcall_err(exec_lua, 'return vim.str_utfindex(_G.test_text, ...)', len + 1)
     )
@@ -538,7 +637,6 @@ describe('lua stdlib', function()
     matches('big failure\nvery async', remove_trace(eval('v:errmsg')))
 
     local screen = Screen.new(60, 5)
-    screen:attach()
     screen:expect {
       grid = [[
       ^                                                            |
@@ -1304,7 +1402,6 @@ describe('lua stdlib', function()
     end)
 
     local screen = Screen.new(50, 7)
-    screen:attach()
     exec_lua([[
       timer = vim.uv.new_timer()
       timer:start(20, 0, function ()
@@ -1317,7 +1414,7 @@ describe('lua stdlib', function()
     screen:expect {
       grid = [[
       {9:[string "<nvim>"]:6: E5560: rpcrequest must not be}|
-      {9: called in a lua loop callback}                    |
+      {9: called in a fast event context}                   |
       {9:stack traceback:}                                  |
       {9:        [C]: in function 'rpcrequest'}             |
       {9:        [string "<nvim>"]:6: in function <[string }|
@@ -1326,7 +1423,9 @@ describe('lua stdlib', function()
     ]],
     }
     feed('<cr>')
-    eq({ 3, NIL }, api.nvim_get_var('yy'))
+    retry(10, nil, function()
+      eq({ 3, NIL }, api.nvim_get_var('yy'))
+    end)
 
     exec_lua([[timer:close()]])
   end)
@@ -1363,7 +1462,79 @@ describe('lua stdlib', function()
     eq('{"a": {}, "b": []}', exec_lua([[ return vim.fn.json_encode({a=vim.empty_dict(), b={}}) ]]))
   end)
 
-  it('vim.validate', function()
+  it('vim.validate (fast form)', function()
+    exec_lua("vim.validate('arg1', {}, 'table')")
+    exec_lua("vim.validate('arg1', nil, 'table', true)")
+    exec_lua("vim.validate('arg1', { foo='foo' }, 'table')")
+    exec_lua("vim.validate('arg1', { 'foo' }, 'table')")
+    exec_lua("vim.validate('arg1', 'foo', 'string')")
+    exec_lua("vim.validate('arg1', nil, 'string', true)")
+    exec_lua("vim.validate('arg1', 1, 'number')")
+    exec_lua("vim.validate('arg1', 0, 'number')")
+    exec_lua("vim.validate('arg1', 0.1, 'number')")
+    exec_lua("vim.validate('arg1', nil, 'number', true)")
+    exec_lua("vim.validate('arg1', true, 'boolean')")
+    exec_lua("vim.validate('arg1', false, 'boolean')")
+    exec_lua("vim.validate('arg1', nil, 'boolean', true)")
+    exec_lua("vim.validate('arg1', function()end, 'function')")
+    exec_lua("vim.validate('arg1', nil, 'function', true)")
+    exec_lua("vim.validate('arg1', nil, 'nil')")
+    exec_lua("vim.validate('arg1', nil, 'nil', true)")
+    exec_lua("vim.validate('arg1', coroutine.create(function()end), 'thread')")
+    exec_lua("vim.validate('arg1', nil, 'thread', true)")
+    exec_lua("vim.validate('arg1', 2, function(a) return (a % 2) == 0  end, 'even number')")
+    exec_lua("vim.validate('arg1', 5, {'number', 'string'})")
+    exec_lua("vim.validate('arg2', 'foo', {'number', 'string'})")
+
+    matches('arg1: expected number, got nil', pcall_err(vim.validate, 'arg1', nil, 'number'))
+    matches('arg1: expected string, got nil', pcall_err(vim.validate, 'arg1', nil, 'string'))
+    matches('arg1: expected table, got nil', pcall_err(vim.validate, 'arg1', nil, 'table'))
+    matches('arg1: expected function, got nil', pcall_err(vim.validate, 'arg1', nil, 'function'))
+    matches('arg1: expected string, got number', pcall_err(vim.validate, 'arg1', 5, 'string'))
+    matches('arg1: expected table, got number', pcall_err(vim.validate, 'arg1', 5, 'table'))
+    matches('arg1: expected function, got number', pcall_err(vim.validate, 'arg1', 5, 'function'))
+    matches('arg1: expected number, got string', pcall_err(vim.validate, 'arg1', '5', 'number'))
+    matches('arg1: expected x, got number', pcall_err(exec_lua, "vim.validate('arg1', 1, 'x')"))
+    matches('invalid validator: 1', pcall_err(exec_lua, "vim.validate('arg1', 1, 1)"))
+    matches('invalid arguments', pcall_err(exec_lua, "vim.validate('arg1', { 1 })"))
+
+    -- Validated parameters are required by default.
+    matches(
+      'arg1: expected string, got nil',
+      pcall_err(exec_lua, "vim.validate('arg1',  nil, 'string')")
+    )
+    -- Explicitly required.
+    matches(
+      'arg1: expected string, got nil',
+      pcall_err(exec_lua, "vim.validate('arg1', nil, 'string', false)")
+    )
+
+    matches(
+      'arg1: expected table, got number',
+      pcall_err(exec_lua, "vim.validate('arg1', 1, 'table')")
+    )
+
+    matches(
+      'arg1: expected even number, got 3',
+      pcall_err(exec_lua, "vim.validate('arg1', 3, function(a) return a == 1 end, 'even number')")
+    )
+    matches(
+      'arg1: expected %?, got 3',
+      pcall_err(exec_lua, "vim.validate('arg1', 3, function(a) return a == 1 end)")
+    )
+    matches(
+      'arg1: expected number|string, got nil',
+      pcall_err(exec_lua, "vim.validate('arg1', nil, {'number', 'string'})")
+    )
+
+    -- Pass an additional message back.
+    matches(
+      'arg1: expected %?, got 3. Info: TEST_MSG',
+      pcall_err(exec_lua, "vim.validate('arg1', 3, function(a) return a == 1, 'TEST_MSG' end)")
+    )
+  end)
+
+  it('vim.validate (spec form)', function()
     exec_lua("vim.validate{arg1={{}, 'table' }}")
     exec_lua("vim.validate{arg1={{}, 't' }}")
     exec_lua("vim.validate{arg1={nil, 't', true }}")
@@ -1392,29 +1563,11 @@ describe('lua stdlib', function()
     exec_lua("vim.validate{arg1={{}, 't' }, arg2={ 'foo', 's' }}")
     exec_lua("vim.validate{arg1={2, function(a) return (a % 2) == 0  end, 'even number' }}")
     exec_lua("vim.validate{arg1={5, {'n', 's'} }, arg2={ 'foo', {'n', 's'} }}")
-    vim.validate('arg1', 5, 'number')
-    vim.validate('arg1', '5', 'string')
-    vim.validate('arg1', { 5 }, 'table')
-    vim.validate('arg1', function()
-      return 5
-    end, 'function')
-    vim.validate('arg1', nil, 'number', true)
-    vim.validate('arg1', nil, 'string', true)
-    vim.validate('arg1', nil, 'table', true)
-    vim.validate('arg1', nil, 'function', true)
 
-    matches('arg1: expected number, got nil', pcall_err(vim.validate, 'arg1', nil, 'number'))
-    matches('arg1: expected string, got nil', pcall_err(vim.validate, 'arg1', nil, 'string'))
-    matches('arg1: expected table, got nil', pcall_err(vim.validate, 'arg1', nil, 'table'))
-    matches('arg1: expected function, got nil', pcall_err(vim.validate, 'arg1', nil, 'function'))
-    matches('arg1: expected string, got number', pcall_err(vim.validate, 'arg1', 5, 'string'))
-    matches('arg1: expected table, got number', pcall_err(vim.validate, 'arg1', 5, 'table'))
-    matches('arg1: expected function, got number', pcall_err(vim.validate, 'arg1', 5, 'function'))
-    matches('arg1: expected number, got string', pcall_err(vim.validate, 'arg1', '5', 'number'))
     matches('expected table, got number', pcall_err(exec_lua, "vim.validate{ 1, 'x' }"))
-    matches('invalid type name: x', pcall_err(exec_lua, "vim.validate{ arg1={ 1, 'x' }}"))
-    matches('invalid type name: 1', pcall_err(exec_lua, 'vim.validate{ arg1={ 1, 1 }}'))
-    matches('invalid type name: nil', pcall_err(exec_lua, 'vim.validate{ arg1={ 1 }}'))
+    matches('arg1: expected x, got number', pcall_err(exec_lua, "vim.validate{ arg1={ 1, 'x' }}"))
+    matches('invalid validator: 1', pcall_err(exec_lua, 'vim.validate{ arg1={ 1, 1 }}'))
+    matches('invalid validator: nil', pcall_err(exec_lua, 'vim.validate{ arg1={ 1 }}'))
 
     -- Validated parameters are required by default.
     matches(
@@ -1975,7 +2128,6 @@ describe('lua stdlib', function()
     eq({ 1, 5 }, api.nvim_win_get_cursor(0))
 
     local screen = Screen.new(60, 3)
-    screen:attach()
     eq(1, eval('v:hlsearch'))
     screen:expect {
       grid = [[
@@ -3157,10 +3309,17 @@ describe('lua stdlib', function()
       eq('inext lines<ESC>', exec_lua [[return table.concat(keys, '')]])
     end)
 
-    it('skips any function that caused an error', function()
+    it('skips any function that caused an error and shows stacktrace', function()
       insert([[hello world]])
 
       exec_lua [[
+        local function ErrF2()
+          error("Dumb Error")
+        end
+        local function ErrF1()
+          ErrF2()
+        end
+
         keys = {}
 
         return vim.on_key(function(buf)
@@ -3171,7 +3330,7 @@ describe('lua stdlib', function()
           table.insert(keys, buf)
 
           if buf == 'l' then
-            error("Dumb Error")
+            ErrF1()
           end
         end)
       ]]
@@ -3181,6 +3340,19 @@ describe('lua stdlib', function()
 
       -- Only the first letter gets added. After that we remove the callback
       eq('inext l', exec_lua [[ return table.concat(keys, '') ]])
+
+      local errmsg = api.nvim_get_vvar('errmsg')
+      matches(
+        [[
+^Error executing vim%.on%_key%(%) callbacks:.*
+With ns%_id %d+: .*: Dumb Error
+stack traceback:
+.*: in function 'error'
+.*: in function 'ErrF2'
+.*: in function 'ErrF1'
+.*]],
+        errmsg
+      )
     end)
 
     it('argument 1 is keys after mapping, argument 2 is typed keys', function()
@@ -3223,6 +3395,109 @@ describe('lua stdlib', function()
       feed('<C-C>')
       eq('/', exec_lua([[return _G.ctrl_c_cmdtype]]))
     end)
+
+    it('callback is not invoked recursively #30752', function()
+      local screen = Screen.new(60, 10)
+      exec_lua([[
+        vim.on_key(function(key, typed)
+          vim.api.nvim_echo({
+            { 'key_cb\n' },
+            { ("KEYCB: key '%s', typed '%s'\n"):format(key, typed) },
+          }, false, {})
+        end)
+      ]])
+      feed('^')
+      screen:expect([[
+                                                                    |
+        {1:~                                                           }|*5
+        {3:                                                            }|
+        key_cb                                                      |
+        KEYCB: key '^', typed '^'                                   |
+        {6:Press ENTER or type command to continue}^                     |
+      ]])
+      feed('<C-C>')
+      screen:expect([[
+                                                                    |
+        {1:~                                                           }|*3
+        {3:                                                            }|
+        key_cb                                                      |
+        KEYCB: key '^', typed '^'                                   |
+        key_cb                                                      |
+        KEYCB: key '{18:^C}', typed '{18:^C}'                                 |
+        {6:Press ENTER or type command to continue}^                     |
+      ]])
+      feed('<C-C>')
+      screen:expect([[
+        ^                                                            |
+        {1:~                                                           }|*8
+                                                                    |
+      ]])
+    end)
+
+    it('can discard input', function()
+      clear()
+      -- discard every other normal 'x' command
+      exec_lua [[
+        n_key = 0
+
+        vim.on_key(function(buf, typed_buf)
+          if typed_buf == 'x' then
+            n_key = n_key + 1
+          end
+          return (n_key % 2 == 0) and "" or nil
+        end)
+      ]]
+
+      api.nvim_buf_set_lines(0, 0, -1, true, { '54321' })
+
+      feed('x')
+      expect('4321')
+      feed('x')
+      expect('4321')
+      feed('x')
+      expect('321')
+      feed('x')
+      expect('321')
+    end)
+
+    it('callback invalid return', function()
+      clear()
+      -- second key produces an error which removes the callback
+      exec_lua [[
+        n_call = 0
+
+        vim.on_key(function(buf, typed_buf)
+          if typed_buf == 'x' then
+            n_call = n_call + 1
+          end
+          return n_call >= 2 and '!' or nil
+        end)
+      ]]
+
+      api.nvim_buf_set_lines(0, 0, -1, true, { '54321' })
+
+      local function cleanup_msg(msg)
+        return msg:gsub('^Error .*\nWith ns%_id %d+: ', '')
+      end
+
+      feed('x')
+      eq(1, exec_lua [[ return n_call ]])
+
+      eq(1, exec_lua [[ return vim.on_key(nil, nil) ]])
+
+      eq('', cleanup_msg(eval('v:errmsg')))
+      feed('x')
+      eq(2, exec_lua [[ return n_call ]])
+      eq('return string must be empty', cleanup_msg(eval('v:errmsg')))
+      command('let v:errmsg = ""')
+
+      eq(0, exec_lua [[ return vim.on_key(nil, nil) ]])
+
+      feed('x')
+      eq(2, exec_lua [[ return n_call ]])
+      expect('21')
+      eq('', cleanup_msg(eval('v:errmsg')))
+    end)
   end)
 
   describe('vim.wait', function()
@@ -3500,7 +3775,6 @@ describe('lua stdlib', function()
 
     it('fails in fast callbacks #26122', function()
       local screen = Screen.new(80, 10)
-      screen:attach()
       exec_lua([[
         local timer = vim.uv.new_timer()
         timer:start(0, 0, function()
@@ -3509,7 +3783,7 @@ describe('lua stdlib', function()
         end)
       ]])
       screen:expect({
-        any = pesc('E5560: vim.wait must not be called in a lua loop callback'),
+        any = pesc('E5560: vim.wait must not be called in a fast event context'),
       })
       feed('<CR>')
       assert_alive()
@@ -3518,7 +3792,6 @@ describe('lua stdlib', function()
 
   it('vim.notify_once', function()
     local screen = Screen.new(60, 5)
-    screen:attach()
     screen:expect {
       grid = [[
       ^                                                            |
@@ -3715,7 +3988,6 @@ describe('lua stdlib', function()
     it('updates ruler if cursor moved', function()
       -- Fixed for win_execute in vim-patch:8.1.2124, but should've applied to nvim_win_call too!
       local screen = Screen.new(30, 5)
-      screen:attach()
       exec_lua [[
         _G.api = vim.api
         vim.opt.ruler = true
@@ -3858,7 +4130,6 @@ describe('lua stdlib', function()
 
   it('vim.lua_omnifunc', function()
     local screen = Screen.new(60, 5)
-    screen:attach()
     command [[ set omnifunc=v:lua.vim.lua_omnifunc ]]
 
     -- Note: the implementation is shared with lua command line completion.
@@ -4060,11 +4331,16 @@ describe('vim.keymap', function()
     )
 
     matches(
-      'opts: expected table, got function',
+      'rhs: expected string|function, got number',
       pcall_err(exec_lua, [[vim.keymap.set({}, 'x', 42, function() end)]])
     )
 
     matches(
+      'opts: expected table, got function',
+      pcall_err(exec_lua, [[vim.keymap.set({}, 'x', 'x', function() end)]])
+    )
+
+    matches(
       'rhs: expected string|function, got number',
       pcall_err(exec_lua, [[vim.keymap.set('z', 'x', 42)]])
     )
diff --git a/test/functional/lua/with_spec.lua b/test/functional/lua/with_spec.lua
index 99b80ef749..6127e83619 100644
--- a/test/functional/lua/with_spec.lua
+++ b/test/functional/lua/with_spec.lua
@@ -1029,7 +1029,6 @@ describe('vim._with', function()
         [1] = { bold = true, reverse = true },
         [2] = { bold = true, foreground = Screen.colors.Blue },
       }
-      screen:attach()
       exec_lua [[ vim._with({ silent = true }, function() vim.cmd.echo('"ccc"') end) ]]
       screen:expect [[
         ^                    |
@@ -1178,7 +1177,6 @@ describe('vim._with', function()
         [1] = { reverse = true },
         [2] = { bold = true, reverse = true },
       }
-      screen:attach()
       exec_lua [[
         vim.opt.ruler = true
         local lines = {}