refactor(api): VALIDATE macros #22256

- VALIDATE() takes a format string
- deduplicate check_string_array
- VALIDATE_RANGE
- validate UI args

7 files changed, 141 insertions, 96 deletions

diff --git a/test/functional/api/autocmd_spec.lua b/test/functional/api/autocmd_spec.lua
index 56b0a4d9b2..f10f18174e 100644
--- a/test/functional/api/autocmd_spec.lua
+++ b/test/functional/api/autocmd_spec.lua
@@ -14,14 +14,31 @@ 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("Cannot use both 'callback' and 'command'", 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', {}}, {}))
     end)
 
     it('doesnt leak when you use ++once', function()
@@ -59,18 +76,8 @@ 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 use 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,
       })
@@ -295,7 +302,7 @@ describe('autocmd api', function()
 
   describe('nvim_get_autocmds', function()
     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 +310,7 @@ 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 +319,7 @@ 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 +329,7 @@ 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 +339,7 @@ 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 +363,7 @@ 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 +371,7 @@ 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"]]
@@ -419,7 +426,7 @@ describe('autocmd api', function()
         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 +438,7 @@ 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 +538,7 @@ 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 +547,7 @@ 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 +558,7 @@ 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",
@@ -625,7 +632,7 @@ describe('autocmd api', function()
         ]], {}))
 
         eq(false, success)
-        matches("Invalid 'pattern' item type: expected String, got Array", code)
+        matches("Invalid 'pattern' item: expected String, got Array", code)
       end)
     end)
 
@@ -640,7 +647,7 @@ 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 +657,7 @@ 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 +694,23 @@ 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 buffer: expected Integer, 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)
 
@@ -1036,7 +1060,7 @@ 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 +1079,7 @@ 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 +1195,16 @@ 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', {}}
+      }))
+    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"')
diff --git a/test/functional/api/buffer_spec.lua b/test/functional/api/buffer_spec.lua
index 6b13729994..d454765edb 100644
--- a/test/functional/api/buffer_spec.lua
+++ b/test/functional/api/buffer_spec.lua
@@ -193,7 +193,7 @@ 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)
 
@@ -553,20 +553,20 @@ 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()
@@ -611,7 +611,7 @@ 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)
diff --git a/test/functional/api/extmark_spec.lua b/test/functional/api/extmark_spec.lua
index fc68f11a67..fab1557204 100644
--- a/test/functional/api/extmark_spec.lua
+++ b/test/functional/api/extmark_spec.lua
@@ -106,7 +106,7 @@ describe('API/extmarks', function()
       end_col = 0,
       end_row = 1
     })
-    eq("Invalid end_col: '(out of range)'",
+    eq("Invalid 'end_col': out of range",
        pcall_err(set_extmark, ns, marks[2], 0, 0, { end_col = 1, end_row = 1 }))
   end)
 
@@ -1362,13 +1362,13 @@ describe('API/extmarks', function()
 
   it('when col = line-length, set the mark on eol', function()
     local invalid_col = init_text:len() + 1
-    eq("Invalid col: '(out of 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("Invalid line: '(out of 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)
 
diff --git a/test/functional/api/highlight_spec.lua b/test/functional/api/highlight_spec.lua
index 7f044977cb..73551de42e 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")
@@ -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 +271,14 @@ 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("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 +298,7 @@ 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 +319,17 @@ 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 +344,14 @@ 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)
diff --git a/test/functional/api/proc_spec.lua b/test/functional/api/proc_spec.lua
index 2028a8fba5..315653af14 100644
--- a/test/functional/api/proc_spec.lua
+++ b/test/functional/api/proc_spec.lua
@@ -42,7 +42,7 @@ 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.*"))
@@ -68,7 +68,7 @@ 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.*"))
diff --git a/test/functional/api/ui_spec.lua b/test/functional/api/ui_spec.lua
index 279cd1856d..5654ef31ef 100644
--- a/test/functional/api/ui_spec.lua
+++ b/test/functional/api/ui_spec.lua
@@ -11,17 +11,37 @@ 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 term_background: expected String, got Boolean',
+      pcall_err(meths.ui_attach, 80, 24, { term_background=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',
diff --git a/test/functional/api/vim_spec.lua b/test/functional/api/vim_spec.lua
index 5c56c90952..469d8e8b6a 100644
--- a/test/functional/api/vim_spec.lua
+++ b/test/functional/api/vim_spec.lua
@@ -1411,9 +1411,9 @@ describe('API', function()
     end)
 
     it('validation', function()
-      eq("Invalid scope (expected 'local' or 'global')",
+      eq("Invalid scope: expected 'local' or 'global'",
         pcall_err(nvim, 'get_option_value', 'scrolloff', {scope = 'bogus'}))
-      eq("Invalid scope (expected 'local' or 'global')",
+      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}))
@@ -2238,7 +2238,7 @@ describe('API', function()
         {'nvim_set_var'},
         {'nvim_set_var', {'avar', 2}},
       }
-      eq('Items in calls array must be arrays of size 2',
+      eq('calls item must be a 2-item Array',
          pcall_err(meths.call_atomic, req))
       -- call before was done, but not after
       eq(1, meths.get_var('avar'))
@@ -3119,11 +3119,11 @@ describe('API', function()
          meths.eval_statusline('a%=b', { fillchar = '\031', maxwidth = 5 }))
     end)
     it('rejects multiple-character fillchar', function()
-      eq('Invalid fillchar (not a single character)',
+      eq('Invalid fillchar: expected single character',
          pcall_err(meths.eval_statusline, '', { fillchar = 'aa' }))
     end)
     it('rejects empty string fillchar', function()
-      eq('Invalid fillchar (not a single character)',
+      eq('Invalid fillchar: expected single character',
          pcall_err(meths.eval_statusline, '', { fillchar = '' }))
     end)
     it('rejects non-string fillchar', function()