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

18 files changed, 1271 insertions, 105 deletions

diff --git a/test/functional/lua/api_spec.lua b/test/functional/lua/api_spec.lua
index f173a15d32..03832978a4 100644
--- a/test/functional/lua/api_spec.lua
+++ b/test/functional/lua/api_spec.lua
@@ -166,7 +166,7 @@ describe('luaeval(vim.api.…)', function()
     eq({v={}}, funcs.luaeval('vim.api.nvim__id_dictionary({v={[vim.type_idx]=vim.types.array, [vim.val_idx]=10, [5]=1, foo=2}})'))
 
     -- If API requests dictionary, then empty table will be the one. This is not
-    -- the case normally because empty table is an empty arrray.
+    -- the case normally because empty table is an empty array.
     eq({}, funcs.luaeval('vim.api.nvim__id_dictionary({})'))
     eq(4, eval([[type(luaeval('vim.api.nvim__id_dictionary({})'))]]))
   end)
diff --git a/test/functional/lua/buffer_updates_spec.lua b/test/functional/lua/buffer_updates_spec.lua
index 10de45274c..2fd44b8b5f 100644
--- a/test/functional/lua/buffer_updates_spec.lua
+++ b/test/functional/lua/buffer_updates_spec.lua
@@ -118,6 +118,24 @@ describe('lua buffer event callbacks: on_lines', function()
     }
     tick = tick + 1
 
+    tick = tick + 1
+    command('redo')
+    check_events {
+      { "test1", "lines", 1, tick, 3, 5, 4, 32 };
+      { "test2", "lines", 1, tick, 3, 5, 4, 32 };
+      { "test2", "changedtick", 1, tick+1 };
+    }
+    tick = tick + 1
+
+    tick = tick + 1
+    command('undo!')
+    check_events {
+      { "test1", "lines", 1, tick, 3, 4, 5, 13 };
+      { "test2", "lines", 1, tick, 3, 4, 5, 13 };
+      { "test2", "changedtick", 1, tick+1 };
+    }
+    tick = tick + 1
+
     -- simulate next callback returning true
     exec_lua("test_unreg = 'test1'")
 
@@ -315,7 +333,7 @@ describe('lua: nvim_buf_attach on_bytes', function()
       start_txt = meths.buf_get_lines(0, 0, -1, true)
     end
     local shadowbytes = table.concat(start_txt, '\n') .. '\n'
-    -- TODO: while we are brewing the real strong coffe,
+    -- TODO: while we are brewing the real strong coffee,
     -- verify should check buf_get_offset after every check_events
     if verify then
       local len = meths.buf_get_offset(0, meths.buf_line_count(0))
diff --git a/test/functional/lua/diagnostic_spec.lua b/test/functional/lua/diagnostic_spec.lua
index f9647f5b6a..d364986ad7 100644
--- a/test/functional/lua/diagnostic_spec.lua
+++ b/test/functional/lua/diagnostic_spec.lua
@@ -16,7 +16,7 @@ describe('vim.diagnostic', function()
     exec_lua [[
       require('vim.diagnostic')
 
-      function make_diagnostic(msg, x1, y1, x2, y2, severity, source)
+      function make_diagnostic(msg, x1, y1, x2, y2, severity, source, code)
         return {
           lnum = x1,
           col = y1,
@@ -25,23 +25,24 @@ describe('vim.diagnostic', function()
           message = msg,
           severity = severity,
           source = source,
+          code = code,
         }
       end
 
-      function make_error(msg, x1, y1, x2, y2, source)
-        return make_diagnostic(msg, x1, y1, x2, y2, vim.diagnostic.severity.ERROR, source)
+      function make_error(msg, x1, y1, x2, y2, source, code)
+        return make_diagnostic(msg, x1, y1, x2, y2, vim.diagnostic.severity.ERROR, source, code)
       end
 
-      function make_warning(msg, x1, y1, x2, y2, source)
-        return make_diagnostic(msg, x1, y1, x2, y2, vim.diagnostic.severity.WARN, source)
+      function make_warning(msg, x1, y1, x2, y2, source, code)
+        return make_diagnostic(msg, x1, y1, x2, y2, vim.diagnostic.severity.WARN, source, code)
       end
 
-      function make_info(msg, x1, y1, x2, y2, source)
-        return make_diagnostic(msg, x1, y1, x2, y2, vim.diagnostic.severity.INFO, source)
+      function make_info(msg, x1, y1, x2, y2, source, code)
+        return make_diagnostic(msg, x1, y1, x2, y2, vim.diagnostic.severity.INFO, source, code)
       end
 
-      function make_hint(msg, x1, y1, x2, y2, source)
-        return make_diagnostic(msg, x1, y1, x2, y2, vim.diagnostic.severity.HINT, source)
+      function make_hint(msg, x1, y1, x2, y2, source, code)
+        return make_diagnostic(msg, x1, y1, x2, y2, vim.diagnostic.severity.HINT, source, code)
       end
 
       function count_diagnostics(bufnr, severity, namespace)
@@ -89,20 +90,25 @@ describe('vim.diagnostic', function()
       'DiagnosticFloatingError',
       'DiagnosticFloatingHint',
       'DiagnosticFloatingInfo',
+      'DiagnosticFloatingOk',
       'DiagnosticFloatingWarn',
       'DiagnosticHint',
       'DiagnosticInfo',
+      'DiagnosticOk',
       'DiagnosticSignError',
       'DiagnosticSignHint',
       'DiagnosticSignInfo',
+      'DiagnosticSignOk',
       'DiagnosticSignWarn',
       'DiagnosticUnderlineError',
       'DiagnosticUnderlineHint',
       'DiagnosticUnderlineInfo',
+      'DiagnosticUnderlineOk',
       'DiagnosticUnderlineWarn',
       'DiagnosticVirtualTextError',
       'DiagnosticVirtualTextHint',
       'DiagnosticVirtualTextInfo',
+      'DiagnosticVirtualTextOk',
       'DiagnosticVirtualTextWarn',
       'DiagnosticWarn',
     }, exec_lua([[return vim.fn.getcompletion('Diagnostic', 'highlight')]]))
@@ -128,6 +134,55 @@ describe('vim.diagnostic', function()
     eq('Diagnostic #1', result[1].message)
   end)
 
+  it('removes diagnostics from the cache when a buffer is removed', function()
+    eq(2, exec_lua [[
+      vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
+      local other_bufnr = vim.fn.bufadd('test | test')
+      local lines = vim.api.nvim_buf_get_lines(diagnostic_bufnr, 0, -1, true)
+      vim.api.nvim_buf_set_lines(other_bufnr, 0, 1, false, lines)
+      vim.cmd('bunload! ' .. other_bufnr)
+
+      vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, {
+        make_error('Diagnostic #1', 1, 1, 1, 1),
+        make_error('Diagnostic #2', 2, 1, 2, 1),
+      })
+      vim.diagnostic.set(diagnostic_ns, other_bufnr, {
+        make_error('Diagnostic #3', 3, 1, 3, 1),
+      })
+      vim.api.nvim_set_current_buf(other_bufnr)
+      vim.opt_local.buflisted = true
+      vim.cmd('bwipeout!')
+      return #vim.diagnostic.get()
+    ]])
+    eq(2, exec_lua [[
+      vim.api.nvim_set_current_buf(diagnostic_bufnr)
+      vim.opt_local.buflisted = false
+      return #vim.diagnostic.get()
+    ]])
+    eq(0, exec_lua [[
+      vim.cmd('bwipeout!')
+      return #vim.diagnostic.get()
+    ]])
+  end)
+
+  it('removes diagnostic from stale cache on reset', function()
+    local diagnostics = exec_lua [[
+      vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, {
+        make_error('Diagnostic #1', 1, 1, 1, 1),
+        make_error('Diagnostic #2', 2, 1, 2, 1),
+      })
+      local other_bufnr = vim.fn.bufadd('test | test')
+      vim.cmd('noautocmd bwipeout! ' .. diagnostic_bufnr)
+      return vim.diagnostic.get(diagnostic_bufnr)
+    ]]
+    eq(2, #diagnostics)
+    diagnostics = exec_lua [[
+      vim.diagnostic.reset()
+      return vim.diagnostic.get()
+    ]]
+    eq(0, #diagnostics)
+  end)
+
   it('resolves buffer number 0 to the current buffer', function()
     eq(2, exec_lua [[
       vim.api.nvim_set_current_buf(diagnostic_bufnr)
@@ -1129,6 +1184,44 @@ end)
       eq(" some_linter: 👀 Warning", result[1][2][1])
       eq(" another_linter: 🔥 Error", result[2][2][1])
     end)
+
+    it('can add a suffix to virtual text', function()
+      eq(' Some error ✘',  exec_lua [[
+        local diagnostics = {
+          make_error('Some error', 0, 0, 0, 0),
+        }
+
+        vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, diagnostics, {
+          underline = false,
+          virtual_text = {
+            prefix = '',
+            suffix = ' ✘',
+          }
+        })
+
+        local extmarks = get_virt_text_extmarks(diagnostic_ns)
+        local virt_text = extmarks[1][4].virt_text[2][1]
+        return virt_text
+      ]])
+
+      eq(' Some error [err-code]',  exec_lua [[
+        local diagnostics = {
+          make_error('Some error', 0, 0, 0, 0, nil, 'err-code'),
+        }
+
+        vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, diagnostics, {
+          underline = false,
+          virtual_text = {
+            prefix = '',
+            suffix = function(diag) return string.format(' [%s]', diag.code) end,
+          }
+        })
+
+        local extmarks = get_virt_text_extmarks(diagnostic_ns)
+        local virt_text = extmarks[1][4].virt_text[2][1]
+        return virt_text
+      ]])
+    end)
   end)
 
   describe('set()', function()
@@ -1745,10 +1838,55 @@ end)
         return lines
       ]])
 
-      eq("Error executing lua: .../diagnostic.lua:0: prefix: expected 'string' or 'table' or 'function', got 42",
+      eq(".../diagnostic.lua:0: prefix: expected string|table|function, got number",
         pcall_err(exec_lua, [[ vim.diagnostic.open_float({ prefix = 42 }) ]]))
     end)
 
+    it('can add a suffix to diagnostics', function()
+      -- Default is to render the diagnostic error code
+      eq({'1. Syntax error [code-x]', '2. Some warning [code-y]'}, exec_lua [[
+        local diagnostics = {
+          make_error("Syntax error", 0, 1, 0, 3, nil, "code-x"),
+          make_warning("Some warning", 1, 1, 1, 3, nil, "code-y"),
+        }
+        vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
+        vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, diagnostics)
+        local float_bufnr, winnr = vim.diagnostic.open_float({header = false, scope = "buffer"})
+        local lines = vim.api.nvim_buf_get_lines(float_bufnr, 0, -1, false)
+        vim.api.nvim_win_close(winnr, true)
+        return lines
+      ]])
+
+      eq({'1. Syntax error', '2. Some warning'}, exec_lua [[
+        local diagnostics = {
+          make_error("Syntax error", 0, 1, 0, 3, nil, "code-x"),
+          make_warning("Some warning", 1, 1, 1, 3, nil, "code-y"),
+        }
+        vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
+        vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, diagnostics)
+        local float_bufnr, winnr = vim.diagnostic.open_float({header = false, scope = "buffer", suffix = ""})
+        local lines = vim.api.nvim_buf_get_lines(float_bufnr, 0, -1, false)
+        vim.api.nvim_win_close(winnr, true)
+        return lines
+      ]])
+
+      -- Suffix is rendered on the last line of a multiline diagnostic
+      eq({'1. Syntax error', '   More context [code-x]'}, exec_lua [[
+        local diagnostics = {
+          make_error("Syntax error\nMore context", 0, 1, 0, 3, nil, "code-x"),
+        }
+        vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
+        vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, diagnostics)
+        local float_bufnr, winnr = vim.diagnostic.open_float({header = false, scope = "buffer"})
+        local lines = vim.api.nvim_buf_get_lines(float_bufnr, 0, -1, false)
+        vim.api.nvim_win_close(winnr, true)
+        return lines
+      ]])
+
+      eq(".../diagnostic.lua:0: suffix: expected string|table|function, got number",
+        pcall_err(exec_lua, [[ vim.diagnostic.open_float({ suffix = 42 }) ]]))
+    end)
+
     it('works with the old signature', function()
       eq({'1. Syntax error'}, exec_lua [[
         local diagnostics = {
@@ -1952,19 +2090,26 @@ end)
     end)
 
     it('triggers the autocommand when diagnostics are set', function()
-      eq(true, exec_lua [[
+      eq({true, true}, exec_lua [[
         -- Set a different buffer as current to test that <abuf> is being set properly in
         -- DiagnosticChanged callbacks
         local tmp = vim.api.nvim_create_buf(false, true)
         vim.api.nvim_set_current_buf(tmp)
 
-        vim.g.diagnostic_autocmd_triggered = 0
-        vim.cmd('autocmd DiagnosticChanged * let g:diagnostic_autocmd_triggered = +expand("<abuf>")')
+        local triggered = {}
+        vim.api.nvim_create_autocmd('DiagnosticChanged', {
+          callback = function(args)
+            triggered = {args.buf, #args.data.diagnostics}
+          end,
+        })
         vim.api.nvim_buf_set_name(diagnostic_bufnr, "test | test")
         vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, {
           make_error('Diagnostic', 0, 0, 0, 0)
         })
-        return vim.g.diagnostic_autocmd_triggered == diagnostic_bufnr
+        return {
+          triggered[1] == diagnostic_bufnr,
+          triggered[2] == 1,
+        }
       ]])
       end)
 
@@ -1979,5 +2124,31 @@ end)
         return vim.g.diagnostic_autocmd_triggered == diagnostic_bufnr
       ]])
       end)
+
+    it("checks if diagnostics are disabled in a buffer", function()
+      eq({true, true, true , true}, exec_lua [[
+        vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, {
+          make_error('Diagnostic #1', 1, 1, 1, 1),
+        })
+        vim.api.nvim_set_current_buf(diagnostic_bufnr)
+        vim.diagnostic.disable()
+        return {
+          vim.diagnostic.is_disabled(),
+          vim.diagnostic.is_disabled(diagnostic_bufnr),
+          vim.diagnostic.is_disabled(diagnostic_bufnr, diagnostic_ns),
+          vim.diagnostic.is_disabled(_, diagnostic_ns),
+        }
+      ]])
+
+      eq({false, false, false , false}, exec_lua [[
+        vim.diagnostic.enable()
+        return {
+          vim.diagnostic.is_disabled(),
+          vim.diagnostic.is_disabled(diagnostic_bufnr),
+          vim.diagnostic.is_disabled(diagnostic_bufnr, diagnostic_ns),
+          vim.diagnostic.is_disabled(_, diagnostic_ns),
+        }
+      ]])
+    end)
   end)
 end)
diff --git a/test/functional/lua/ffi_spec.lua b/test/functional/lua/ffi_spec.lua
index 80c01a2b8c..18b13a8959 100644
--- a/test/functional/lua/ffi_spec.lua
+++ b/test/functional/lua/ffi_spec.lua
@@ -29,32 +29,37 @@ describe('ffi.cdef', function()
         typedef struct window_S win_T;
         typedef struct {} stl_hlrec_t;
         typedef struct {} StlClickRecord;
+        typedef struct {} statuscol_T;
         typedef struct {} Error;
 
         win_T *find_window_by_handle(int Window, Error *err);
 
         int build_stl_str_hl(
           win_T *wp,
-          char_u *out,
+          char *out,
           size_t outlen,
-          char_u *fmt,
-          int use_sandbox,
-          char_u fillchar,
+          char *fmt,
+          char *opt_name,
+          int opt_scope,
+          int fillchar,
           int maxwidth,
           stl_hlrec_t **hltab,
-          StlClickRecord **tabtab
+          StlClickRecord **tabtab,
+          statuscol_T *scp
         );
       ]]
 
       return ffi.C.build_stl_str_hl(
         ffi.C.find_window_by_handle(0, ffi.new('Error')),
-        ffi.new('char_u[1024]'),
+        ffi.new('char[1024]'),
         1024,
-        ffi.cast('char_u*', 'StatusLineOfLength20'),
+        ffi.cast('char*', 'StatusLineOfLength20'),
+        nil,
         0,
         0,
         0,
         nil,
+        nil,
         nil
       )
     ]=])
diff --git a/test/functional/lua/filetype_spec.lua b/test/functional/lua/filetype_spec.lua
index be57b2db31..2a7be53164 100644
--- a/test/functional/lua/filetype_spec.lua
+++ b/test/functional/lua/filetype_spec.lua
@@ -1,6 +1,7 @@
 local helpers = require('test.functional.helpers')(after_each)
 local exec_lua = helpers.exec_lua
 local eq = helpers.eq
+local meths = helpers.meths
 local clear = helpers.clear
 local pathroot = helpers.pathroot
 local command = helpers.command
@@ -94,3 +95,10 @@ describe('vim.filetype', function()
     ]])
   end)
 end)
+
+describe('filetype.lua', function()
+  it('does not override user autocommands that set filetype #20333', function()
+    clear({args={'--clean', '--cmd', 'autocmd BufRead *.md set filetype=notmarkdown', 'README.md'}})
+    eq('notmarkdown', meths.buf_get_option(0, 'filetype'))
+  end)
+end)
diff --git a/test/functional/lua/fs_spec.lua b/test/functional/lua/fs_spec.lua
index 2bcc84db0f..642d36f63a 100644
--- a/test/functional/lua/fs_spec.lua
+++ b/test/functional/lua/fs_spec.lua
@@ -1,4 +1,5 @@
 local helpers = require('test.functional.helpers')(after_each)
+local lfs = require('lfs')
 
 local clear = helpers.clear
 local exec_lua = helpers.exec_lua
@@ -7,10 +8,43 @@ local mkdir_p = helpers.mkdir_p
 local rmdir = helpers.rmdir
 local nvim_dir = helpers.nvim_dir
 local test_build_dir = helpers.test_build_dir
-local iswin = helpers.iswin
 local nvim_prog = helpers.nvim_prog
+local is_os = helpers.is_os
 
-local nvim_prog_basename = iswin() and 'nvim.exe' or 'nvim'
+local nvim_prog_basename = is_os('win') and 'nvim.exe' or 'nvim'
+
+local test_basename_dirname_eq = {
+  '~/foo/',
+  '~/foo',
+  '~/foo/bar.lua',
+  'foo.lua',
+  ' ',
+  '',
+  '.',
+  '..',
+  '../',
+  '~',
+  '/usr/bin',
+  '/usr/bin/gcc',
+  '/',
+  '/usr/',
+  '/usr',
+  'c:/usr',
+  'c:/',
+  'c:',
+  'c:/users/foo',
+  'c:/users/foo/bar.lua',
+  'c:/users/foo/bar/../',
+}
+
+local tests_windows_paths = {
+  'c:\\usr',
+  'c:\\',
+  'c:',
+  'c:\\users\\foo',
+  'c:\\users\\foo\\bar.lua',
+  'c:\\users\\foo\\bar\\..\\',
+}
 
 before_each(clear)
 
@@ -41,19 +75,73 @@ describe('vim.fs', function()
         local nvim_dir = ...
         return vim.fs.dirname(nvim_dir)
       ]], nvim_dir))
+
+      local function test_paths(paths)
+        for _, path in ipairs(paths) do
+          eq(
+            exec_lua([[
+              local path = ...
+              return vim.fn.fnamemodify(path,':h'):gsub('\\', '/')
+            ]], path),
+            exec_lua([[
+              local path = ...
+              return vim.fs.dirname(path)
+            ]], path),
+            path
+          )
+        end
+      end
+
+      test_paths(test_basename_dirname_eq)
+      if is_os('win') then
+        test_paths(tests_windows_paths)
+      end
     end)
   end)
 
   describe('basename()', function()
     it('works', function()
+
       eq(nvim_prog_basename, exec_lua([[
         local nvim_prog = ...
         return vim.fs.basename(nvim_prog)
       ]], nvim_prog))
+
+      local function test_paths(paths)
+        for _, path in ipairs(paths) do
+          eq(
+            exec_lua([[
+              local path = ...
+              return vim.fn.fnamemodify(path,':t'):gsub('\\', '/')
+            ]], path),
+            exec_lua([[
+              local path = ...
+              return vim.fs.basename(path)
+            ]], path),
+            path
+          )
+        end
+      end
+
+      test_paths(test_basename_dirname_eq)
+      if is_os('win') then
+        test_paths(tests_windows_paths)
+      end
     end)
   end)
 
   describe('dir()', function()
+    before_each(function()
+      lfs.mkdir('testd')
+      lfs.mkdir('testd/a')
+      lfs.mkdir('testd/a/b')
+      lfs.mkdir('testd/a/b/c')
+    end)
+
+    after_each(function()
+      rmdir('testd')
+    end)
+
     it('works', function()
       eq(true, exec_lua([[
         local dir, nvim = ...
@@ -65,6 +153,71 @@ describe('vim.fs', function()
         return false
       ]], nvim_dir, nvim_prog_basename))
     end)
+
+    it('works with opts.depth and opts.skip', function()
+      io.open('testd/a1', 'w'):close()
+      io.open('testd/b1', 'w'):close()
+      io.open('testd/c1', 'w'):close()
+      io.open('testd/a/a2', 'w'):close()
+      io.open('testd/a/b2', 'w'):close()
+      io.open('testd/a/c2', 'w'):close()
+      io.open('testd/a/b/a3', 'w'):close()
+      io.open('testd/a/b/b3', 'w'):close()
+      io.open('testd/a/b/c3', 'w'):close()
+      io.open('testd/a/b/c/a4', 'w'):close()
+      io.open('testd/a/b/c/b4', 'w'):close()
+      io.open('testd/a/b/c/c4', 'w'):close()
+
+      local function run(dir, depth, skip)
+         local r = exec_lua([[
+          local dir, depth, skip = ...
+          local r = {}
+          local skip_f
+          if skip then
+            skip_f = function(n)
+              if vim.tbl_contains(skip or {}, n) then
+                return false
+              end
+            end
+          end
+          for name, type_ in vim.fs.dir(dir, { depth = depth, skip = skip_f }) do
+            r[name] = type_
+          end
+          return r
+        ]], dir, depth, skip)
+        return r
+      end
+
+      local exp = {}
+
+      exp['a1'] = 'file'
+      exp['b1'] = 'file'
+      exp['c1'] = 'file'
+      exp['a'] = 'directory'
+
+      eq(exp, run('testd', 1))
+
+      exp['a/a2'] = 'file'
+      exp['a/b2'] = 'file'
+      exp['a/c2'] = 'file'
+      exp['a/b'] = 'directory'
+
+      eq(exp, run('testd', 2))
+
+      exp['a/b/a3'] = 'file'
+      exp['a/b/b3'] = 'file'
+      exp['a/b/c3'] = 'file'
+      exp['a/b/c'] = 'directory'
+
+      eq(exp, run('testd', 3))
+      eq(exp, run('testd', 999, {'a/b/c'}))
+
+      exp['a/b/c/a4'] = 'file'
+      exp['a/b/c/b4'] = 'file'
+      exp['a/b/c/c4'] = 'file'
+
+      eq(exp, run('testd', 999))
+    end)
   end)
 
   describe('find()', function()
@@ -77,6 +230,28 @@ describe('vim.fs', function()
         local dir, nvim = ...
         return vim.fs.find(nvim, { path = dir, type = 'file' })
       ]], test_build_dir, nvim_prog_basename))
+      eq({nvim_dir}, exec_lua([[
+        local dir = ...
+        local parent, name = dir:match('^(.*/)([^/]+)$')
+        return vim.fs.find(name, { path = parent, upward = true, type = 'directory' })
+      ]], nvim_dir))
+    end)
+
+    it('accepts predicate as names', function()
+      eq({test_build_dir}, exec_lua([[
+        local dir = ...
+        local opts = { path = dir, upward = true, type = 'directory' }
+        return vim.fs.find(function(x) return x == 'build' end, opts)
+      ]], nvim_dir))
+      eq({nvim_prog}, exec_lua([[
+        local dir, nvim = ...
+        return vim.fs.find(function(x) return x == nvim end, { path = dir, type = 'file' })
+      ]], test_build_dir, nvim_prog_basename))
+      eq({}, exec_lua([[
+        local dir = ...
+        local opts = { path = dir, upward = true, type = 'directory' }
+        return vim.fs.find(function(x) return x == 'no-match' end, opts)
+      ]], nvim_dir))
     end)
   end)
 
@@ -85,7 +260,7 @@ describe('vim.fs', function()
       eq('C:/Users/jdoe', exec_lua [[ return vim.fs.normalize('C:\\Users\\jdoe') ]])
     end)
     it('works with ~', function()
-      if iswin() then
+      if is_os('win') then
         pending([[$HOME does not exist on Windows ¯\_(ツ)_/¯]])
       end
       eq(os.getenv('HOME') .. '/src/foo', exec_lua [[ return vim.fs.normalize('~/src/foo') ]])
diff --git a/test/functional/lua/help_spec.lua b/test/functional/lua/help_spec.lua
new file mode 100644
index 0000000000..b396e2ba30
--- /dev/null
+++ b/test/functional/lua/help_spec.lua
@@ -0,0 +1,50 @@
+-- Tests for gen_help_html.lua. Validates :help tags/links and HTML doc generation.
+--
+-- TODO: extract parts of gen_help_html.lua into Nvim stdlib?
+
+local helpers = require('test.functional.helpers')(after_each)
+local clear = helpers.clear
+local exec_lua = helpers.exec_lua
+local eq = helpers.eq
+local ok = helpers.ok
+
+describe(':help docs', function()
+  before_each(clear)
+  it('validate', function()
+    -- If this test fails, try these steps (in order):
+    -- 1. Fix/cleanup the :help docs.
+    -- 2. Fix the parser: https://github.com/neovim/tree-sitter-vimdoc
+    -- 3. File a parser bug, and adjust the tolerance of this test in the meantime.
+
+    local rv = exec_lua([[return require('scripts.gen_help_html').validate('./build/runtime/doc')]])
+    -- Check that we actually found helpfiles.
+    ok(rv.helpfiles > 100, '>100 :help files', rv.helpfiles)
+    eq({}, rv.invalid_links, 'invalid tags in :help docs')
+    eq({}, rv.invalid_urls, 'invalid URLs in :help docs')
+    -- Check that parse errors did not increase wildly.
+    -- TODO: Fix all parse errors in :help files.
+    ok(rv.err_count < 250, '<250 parse errors', rv.err_count)
+  end)
+
+  it('gen_help_html.lua generates HTML', function()
+    -- 1. Test that gen_help_html.lua actually works.
+    -- 2. Test that parse errors did not increase wildly. Because we explicitly test only a few
+    --    :help files, we can be precise about the tolerances here.
+
+    local tmpdir = exec_lua('return vim.fs.dirname(vim.fn.tempname())')
+    -- Because gen() is slow (~30s), this test is limited to a few files.
+    local rv = exec_lua([[
+      local to_dir = ...
+      return require('scripts.gen_help_html').gen(
+        './build/runtime/doc',
+        to_dir,
+        { 'pi_health.txt', 'help.txt', 'index.txt', 'nvim.txt', }
+      )
+      ]],
+      tmpdir
+    )
+    eq(4, #rv.helpfiles)
+    eq(0, rv.err_count, 'parse errors in :help docs')
+    eq({}, rv.invalid_links, 'invalid tags in :help docs')
+  end)
+end)
diff --git a/test/functional/lua/inspector_spec.lua b/test/functional/lua/inspector_spec.lua
new file mode 100644
index 0000000000..5e488bb082
--- /dev/null
+++ b/test/functional/lua/inspector_spec.lua
@@ -0,0 +1,56 @@
+local helpers = require('test.functional.helpers')(after_each)
+local exec_lua = helpers.exec_lua
+local eq = helpers.eq
+local eval = helpers.eval
+local clear = helpers.clear
+
+describe('vim.inspect_pos', function()
+  before_each(function()
+    clear()
+  end)
+
+  it('it returns items', function()
+    local ret = exec_lua([[
+      local buf = vim.api.nvim_create_buf(true, false)
+      vim.api.nvim_set_current_buf(buf)
+      vim.api.nvim_buf_set_lines(0, 0, -1, false, {"local a = 123"})
+      vim.api.nvim_buf_set_option(buf, "filetype", "lua")
+      vim.cmd("syntax on")
+      return {buf, vim.inspect_pos(0, 0, 10)}
+    ]])
+    local buf, items = unpack(ret)
+    eq('', eval('v:errmsg'))
+    eq({
+      buffer = buf,
+      col = 10,
+      row = 0,
+      extmarks = {},
+      treesitter = {},
+      semantic_tokens = {},
+      syntax = {
+        {
+          hl_group = 'luaNumber',
+          hl_group_link = 'Constant',
+        },
+      },
+    }, items)
+  end)
+end)
+
+describe('vim.show_pos', function()
+  before_each(function()
+    clear()
+  end)
+
+  it('it does not error', function()
+    exec_lua([[
+      local buf = vim.api.nvim_create_buf(true, false)
+      vim.api.nvim_set_current_buf(buf)
+      vim.api.nvim_buf_set_lines(0, 0, -1, false, {"local a = 123"})
+      vim.api.nvim_buf_set_option(buf, "filetype", "lua")
+      vim.cmd("syntax on")
+      return {buf, vim.show_pos(0, 0, 10)}
+    ]])
+    eq('', eval('v:errmsg'))
+  end)
+end)
diff --git a/test/functional/lua/overrides_spec.lua b/test/functional/lua/overrides_spec.lua
index 32c1615a45..3f107811ae 100644
--- a/test/functional/lua/overrides_spec.lua
+++ b/test/functional/lua/overrides_spec.lua
@@ -8,12 +8,12 @@ local feed = helpers.feed
 local clear = helpers.clear
 local funcs = helpers.funcs
 local meths = helpers.meths
-local iswin = helpers.iswin
 local command = helpers.command
 local write_file = helpers.write_file
 local exec_capture = helpers.exec_capture
 local exec_lua = helpers.exec_lua
 local pcall_err = helpers.pcall_err
+local is_os = helpers.is_os
 
 local screen
 
@@ -135,7 +135,7 @@ describe('print', function()
         print("very slow")
         vim.api.nvim_command("sleep 1m") -- force deferred event processing
       end
-    ]], (iswin() and "timeout 1") or "sleep 0.1")
+    ]], (is_os('win') and "timeout 1") or "sleep 0.1")
     eq('very slow\nvery fast', exec_capture('lua test()'))
   end)
 end)
diff --git a/test/functional/lua/runtime_spec.lua b/test/functional/lua/runtime_spec.lua
index e9c34c9228..b659f2eacb 100644
--- a/test/functional/lua/runtime_spec.lua
+++ b/test/functional/lua/runtime_spec.lua
@@ -4,6 +4,7 @@ local clear = helpers.clear
 local eq = helpers.eq
 local eval = helpers.eval
 local exec = helpers.exec
+local funcs = helpers.funcs
 local mkdir_p = helpers.mkdir_p
 local rmdir = helpers.rmdir
 local write_file = helpers.write_file
@@ -29,6 +30,7 @@ describe('runtime:', function()
 
   after_each(function()
     rmdir(plug_dir)
+    exec('bwipe!')
   end)
 
   describe('colors', function()
@@ -39,6 +41,8 @@ describe('runtime:', function()
       mkdir_p(colorscheme_folder)
       write_file(colorscheme_file, [[vim.g.lua_colorscheme = 1]])
 
+      eq({'new_colorscheme'}, funcs.getcompletion('new_c', 'color'))
+
       exec('colorscheme new_colorscheme')
 
       eq(1, eval('g:lua_colorscheme'))
@@ -64,23 +68,25 @@ describe('runtime:', function()
     it('loads lua compilers', function()
       local compiler_file = compiler_folder .. sep .. 'new_compiler.lua'
       mkdir_p(compiler_folder)
-      write_file(compiler_file, [[vim.g.lua_compiler = 1]])
+      write_file(compiler_file, [[vim.b.lua_compiler = 1]])
+
+      eq({'new_compiler'}, funcs.getcompletion('new_c', 'compiler'))
 
       exec('compiler new_compiler')
 
-      eq(1, eval('g:lua_compiler'))
+      eq(1, eval('b:lua_compiler'))
       rmdir(compiler_folder)
     end)
 
     it('loads vim compilers when both lua and vim version exist', function()
       local compiler_file = compiler_folder .. sep .. 'new_compiler'
       mkdir_p(compiler_folder)
-      write_file(compiler_file..'.vim', [[let g:compiler = 'vim']])
-      write_file(compiler_file..'.lua', [[vim.g.compiler = 'lua']])
+      write_file(compiler_file..'.vim', [[let b:compiler = 'vim']])
+      write_file(compiler_file..'.lua', [[vim.b.compiler = 'lua']])
 
       exec('compiler new_compiler')
 
-      eq('vim', eval('g:compiler'))
+      eq('vim', eval('b:compiler'))
       rmdir(compiler_folder)
     end)
   end)
@@ -91,10 +97,12 @@ describe('runtime:', function()
     it('loads lua ftplugins', function()
       local ftplugin_file = table.concat({ftplugin_folder , 'new-ft.lua'}, sep)
       mkdir_p(ftplugin_folder)
-      write_file(ftplugin_file , [[vim.g.lua_ftplugin = 1]])
+      write_file(ftplugin_file , [[vim.b.lua_ftplugin = 1]])
+
+      eq({'new-ft'}, funcs.getcompletion('new-f', 'filetype'))
 
       exec [[set filetype=new-ft]]
-      eq(1, eval('g:lua_ftplugin'))
+      eq(1, eval('b:lua_ftplugin'))
       rmdir(ftplugin_folder)
     end)
   end)
@@ -105,10 +113,12 @@ describe('runtime:', function()
     it('loads lua indents', function()
       local indent_file = table.concat({indent_folder , 'new-ft.lua'}, sep)
       mkdir_p(indent_folder)
-      write_file(indent_file , [[vim.g.lua_indent = 1]])
+      write_file(indent_file , [[vim.b.lua_indent = 1]])
+
+      eq({'new-ft'}, funcs.getcompletion('new-f', 'filetype'))
 
       exec [[set filetype=new-ft]]
-      eq(1, eval('g:lua_indent'))
+      eq(1, eval('b:lua_indent'))
       rmdir(indent_folder)
     end)
   end)
@@ -116,24 +126,32 @@ describe('runtime:', function()
   describe('syntax', function()
     local syntax_folder = table.concat({plug_dir, 'syntax'}, sep)
 
-    it('loads lua syntaxes on filetype change', function()
+    before_each(function()
       local syntax_file = table.concat({syntax_folder , 'my-lang.lua'}, sep)
       mkdir_p(syntax_folder)
-      write_file(syntax_file , [[vim.g.lua_syntax = 1]])
+      write_file(syntax_file , [[vim.b.current_syntax = 'my-lang']])
+      exec([[let b:current_syntax = '']])
+    end)
 
+    it('loads lua syntaxes on filetype change', function()
       exec('set filetype=my-lang')
-      eq(1, eval('g:lua_syntax'))
-      rmdir(syntax_folder)
+      eq('my-lang', eval('b:current_syntax'))
     end)
 
     it('loads lua syntaxes on syntax change', function()
-      local syntax_file = table.concat({syntax_folder , 'my-lang.lua'}, sep)
-      mkdir_p(syntax_folder)
-      write_file(syntax_file , [[vim.g.lua_syntax = 5]])
-
       exec('set syntax=my-lang')
-      eq(5, eval('g:lua_syntax'))
-      rmdir(syntax_folder)
+      eq('my-lang', eval('b:current_syntax'))
+    end)
+
+    it('loads lua syntaxes for :ownsyntax', function()
+      exec('ownsyntax my-lang')
+      eq('my-lang', eval('w:current_syntax'))
+      eq('', eval('b:current_syntax'))
+    end)
+
+    it('lua syntaxes are included in cmdline completion', function()
+      eq({'my-lang'}, funcs.getcompletion('my-l', 'filetype'))
+      eq({'my-lang'}, funcs.getcompletion('my-l', 'syntax'))
     end)
   end)
 
diff --git a/test/functional/lua/secure_spec.lua b/test/functional/lua/secure_spec.lua
new file mode 100644
index 0000000000..2647b2be46
--- /dev/null
+++ b/test/functional/lua/secure_spec.lua
@@ -0,0 +1,284 @@
+local helpers = require('test.functional.helpers')(after_each)
+local Screen = require('test.functional.ui.screen')
+
+local eq = helpers.eq
+local clear = helpers.clear
+local command = helpers.command
+local pathsep = helpers.get_pathsep()
+local is_os = helpers.is_os
+local curbufmeths = helpers.curbufmeths
+local exec_lua = helpers.exec_lua
+local feed_command = helpers.feed_command
+local feed = helpers.feed
+local funcs = helpers.funcs
+local pcall_err = helpers.pcall_err
+local matches = helpers.matches
+
+describe('vim.secure', function()
+  describe('read()', function()
+    local xstate = 'Xstate'
+
+    setup(function()
+      helpers.mkdir_p(xstate .. pathsep .. (is_os('win') and 'nvim-data' or 'nvim'))
+    end)
+
+    teardown(function()
+      helpers.rmdir(xstate)
+    end)
+
+    before_each(function()
+      helpers.write_file('Xfile', [[
+        let g:foobar = 42
+      ]])
+      clear{env={XDG_STATE_HOME=xstate}}
+    end)
+
+    after_each(function()
+      os.remove('Xfile')
+      helpers.rmdir(xstate)
+    end)
+
+    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},
+        [3] = {bold = true, foreground = Screen.colors.SeaGreen},
+        [4] = {reverse = true},
+      })
+
+      local cwd = funcs.getcwd()
+
+      -- Need to use feed_command instead of exec_lua because of the confirmation prompt
+      feed_command([[lua vim.secure.read('Xfile')]])
+      screen:expect{grid=[[
+                                                                                        |
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+        {2:                                                                                }|
+        :lua vim.secure.read('Xfile')                                                   |
+        {3:]] .. cwd .. pathsep .. [[Xfile is untrusted}{MATCH:%s+}|
+        {3:[i]gnore, (v)iew, (d)eny, (a)llow: }^                                             |
+      ]]}
+      feed('d')
+      screen:expect{grid=[[
+        ^                                                                                |
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+                                                                                        |
+      ]]}
+
+      local trust = helpers.read_file(funcs.stdpath('state') .. pathsep .. 'trust')
+      eq(string.format('! %s', cwd .. pathsep .. 'Xfile'), vim.trim(trust))
+      eq(helpers.NIL, exec_lua([[return vim.secure.read('Xfile')]]))
+
+      os.remove(funcs.stdpath('state') .. pathsep .. 'trust')
+
+      feed_command([[lua vim.secure.read('Xfile')]])
+      screen:expect{grid=[[
+                                                                                        |
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+        {2:                                                                                }|
+        :lua vim.secure.read('Xfile')                                                   |
+        {3:]] .. cwd .. pathsep .. [[Xfile is untrusted}{MATCH:%s+}|
+        {3:[i]gnore, (v)iew, (d)eny, (a)llow: }^                                             |
+      ]]}
+      feed('a')
+      screen:expect{grid=[[
+        ^                                                                                |
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+                                                                                        |
+      ]]}
+
+      local hash = funcs.sha256(helpers.read_file('Xfile'))
+      trust = helpers.read_file(funcs.stdpath('state') .. pathsep .. 'trust')
+      eq(string.format('%s %s', hash, cwd .. pathsep .. 'Xfile'), vim.trim(trust))
+      eq(helpers.NIL, exec_lua([[vim.secure.read('Xfile')]]))
+
+      os.remove(funcs.stdpath('state') .. pathsep .. 'trust')
+
+      feed_command([[lua vim.secure.read('Xfile')]])
+      screen:expect{grid=[[
+                                                                                        |
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+        {2:                                                                                }|
+        :lua vim.secure.read('Xfile')                                                   |
+        {3:]] .. cwd .. pathsep .. [[Xfile is untrusted}{MATCH:%s+}|
+        {3:[i]gnore, (v)iew, (d)eny, (a)llow: }^                                             |
+      ]]}
+      feed('i')
+      screen:expect{grid=[[
+        ^                                                                                |
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+                                                                                        |
+      ]]}
+
+      -- Trust database is not updated
+      trust = helpers.read_file(funcs.stdpath('state') .. pathsep .. 'trust')
+      eq(nil, trust)
+
+      feed_command([[lua vim.secure.read('Xfile')]])
+      screen:expect{grid=[[
+                                                                                        |
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+        {2:                                                                                }|
+        :lua vim.secure.read('Xfile')                                                   |
+        {3:]] .. cwd .. pathsep .. [[Xfile is untrusted}{MATCH:%s+}|
+        {3:[i]gnore, (v)iew, (d)eny, (a)llow: }^                                             |
+      ]]}
+      feed('v')
+      screen:expect{grid=[[
+          ^let g:foobar = 42                                                             |
+        {1:~                                                                               }|
+        {1:~                                                                               }|
+        {2:]] .. funcs.fnamemodify(cwd, ':~') .. pathsep .. [[Xfile [RO]{MATCH:%s+}|
+                                                                                        |
+        {1:~                                                                               }|
+        {4:[No Name]                                                                       }|
+                                                                                        |
+      ]]}
+
+      -- Trust database is not updated
+      trust = helpers.read_file(funcs.stdpath('state') .. pathsep .. 'trust')
+      eq(nil, trust)
+
+      -- Cannot write file
+      pcall_err(command, 'write')
+      eq(true, curbufmeths.get_option('readonly'))
+    end)
+  end)
+
+  describe('trust()', function()
+    local xstate = 'Xstate'
+
+    setup(function()
+      helpers.mkdir_p(xstate .. pathsep .. (is_os('win') and 'nvim-data' or 'nvim'))
+    end)
+
+    teardown(function()
+      helpers.rmdir(xstate)
+    end)
+
+    before_each(function()
+      helpers.write_file('test_file', 'test')
+    end)
+
+    after_each(function()
+      os.remove('test_file')
+    end)
+
+    it('returns error when passing both path and bufnr', function()
+      matches('"path" and "bufnr" are mutually exclusive',
+        pcall_err(exec_lua, [[vim.secure.trust({action='deny', bufnr=0, path='test_file'})]]))
+    end)
+
+    it('returns error when passing neither path or bufnr', function()
+      matches('one of "path" or "bufnr" is required',
+        pcall_err(exec_lua, [[vim.secure.trust({action='deny'})]]))
+    end)
+
+    it('trust then deny then remove a file using bufnr', function()
+      local cwd = funcs.getcwd()
+      local hash = funcs.sha256(helpers.read_file('test_file'))
+      local full_path = cwd .. pathsep .. 'test_file'
+
+      command('edit test_file')
+      eq({true, full_path}, exec_lua([[return {vim.secure.trust({action='allow', bufnr=0})}]]))
+      local trust = helpers.read_file(funcs.stdpath('state') .. pathsep .. 'trust')
+      eq(string.format('%s %s', hash, full_path), vim.trim(trust))
+
+      eq({true, full_path}, exec_lua([[return {vim.secure.trust({action='deny', bufnr=0})}]]))
+      trust = helpers.read_file(funcs.stdpath('state') .. pathsep .. 'trust')
+      eq(string.format('! %s', full_path), vim.trim(trust))
+
+      eq({true, full_path}, exec_lua([[return {vim.secure.trust({action='remove', bufnr=0})}]]))
+      trust = helpers.read_file(funcs.stdpath('state') .. pathsep .. 'trust')
+      eq('', vim.trim(trust))
+    end)
+
+    it('deny then trust then remove a file using bufnr', function()
+      local cwd = funcs.getcwd()
+      local hash = funcs.sha256(helpers.read_file('test_file'))
+      local full_path = cwd .. pathsep .. 'test_file'
+
+      command('edit test_file')
+      eq({true, full_path}, exec_lua([[return {vim.secure.trust({action='deny', bufnr=0})}]]))
+      local trust = helpers.read_file(funcs.stdpath('state') .. pathsep .. 'trust')
+      eq(string.format('! %s', full_path), vim.trim(trust))
+
+      eq({true, full_path}, exec_lua([[return {vim.secure.trust({action='allow', bufnr=0})}]]))
+      trust = helpers.read_file(funcs.stdpath('state') .. pathsep .. 'trust')
+      eq(string.format('%s %s', hash, full_path), vim.trim(trust))
+
+      eq({true, full_path}, exec_lua([[return {vim.secure.trust({action='remove', bufnr=0})}]]))
+      trust = helpers.read_file(funcs.stdpath('state') .. pathsep .. 'trust')
+      eq('', vim.trim(trust))
+    end)
+
+    it('trust using bufnr then deny then remove a file using path', function()
+      local cwd = funcs.getcwd()
+      local hash = funcs.sha256(helpers.read_file('test_file'))
+      local full_path = cwd .. pathsep .. 'test_file'
+
+      command('edit test_file')
+      eq({true, full_path}, exec_lua([[return {vim.secure.trust({action='allow', bufnr=0})}]]))
+      local trust = helpers.read_file(funcs.stdpath('state') .. pathsep .. 'trust')
+      eq(string.format('%s %s', hash, full_path), vim.trim(trust))
+
+      eq({true, full_path}, exec_lua([[return {vim.secure.trust({action='deny', path='test_file'})}]]))
+      trust = helpers.read_file(funcs.stdpath('state') .. pathsep .. 'trust')
+      eq(string.format('! %s', full_path), vim.trim(trust))
+
+      eq({true, full_path}, exec_lua([[return {vim.secure.trust({action='remove', path='test_file'})}]]))
+      trust = helpers.read_file(funcs.stdpath('state') .. pathsep .. 'trust')
+      eq('', vim.trim(trust))
+    end)
+
+    it('deny then trust then remove a file using bufnr', function()
+      local cwd = funcs.getcwd()
+      local hash = funcs.sha256(helpers.read_file('test_file'))
+      local full_path = cwd .. pathsep .. 'test_file'
+
+      command('edit test_file')
+      eq({true, full_path}, exec_lua([[return {vim.secure.trust({action='deny', path='test_file'})}]]))
+      local trust = helpers.read_file(funcs.stdpath('state') .. pathsep .. 'trust')
+      eq(string.format('! %s', full_path), vim.trim(trust))
+
+      eq({true, full_path}, exec_lua([[return {vim.secure.trust({action='allow', bufnr=0})}]]))
+      trust = helpers.read_file(funcs.stdpath('state') .. pathsep .. 'trust')
+      eq(string.format('%s %s', hash, full_path), vim.trim(trust))
+
+      eq({true, full_path}, exec_lua([[return {vim.secure.trust({action='remove', path='test_file'})}]]))
+      trust = helpers.read_file(funcs.stdpath('state') .. pathsep .. 'trust')
+      eq('', vim.trim(trust))
+    end)
+
+    it('trust returns error when buffer not associated to file', function()
+      command('new')
+      eq({false, 'buffer is not associated with a file'},
+        exec_lua([[return {vim.secure.trust({action='allow', bufnr=0})}]]))
+    end)
+  end)
+end)
diff --git a/test/functional/lua/spell_spec.lua b/test/functional/lua/spell_spec.lua
index 7e831f16a7..b3de6a0912 100644
--- a/test/functional/lua/spell_spec.lua
+++ b/test/functional/lua/spell_spec.lua
@@ -15,7 +15,7 @@ describe('vim.spell', function()
     end
 
     it('can handle nil', function()
-      eq([[Error executing lua: [string "<nvim>"]:0: bad argument #1 to 'check' (expected string)]],
+      eq([[bad argument #1 to 'check' (expected string)]],
         pcall_err(exec_lua, [[vim.spell.check(nil)]]))
     end)
 
diff --git a/test/functional/lua/thread_spec.lua b/test/functional/lua/thread_spec.lua
index e183ce3a57..c7f2783cf3 100644
--- a/test/functional/lua/thread_spec.lua
+++ b/test/functional/lua/thread_spec.lua
@@ -272,7 +272,7 @@ describe('threadpool', function()
       work:queue({})
     ]])
 
-    eq([[Error executing lua: [string "<nvim>"]:0: Error: thread arg not support type 'function' at 1]],
+    eq([[Error: thread arg not support type 'function' at 1]],
        status)
   end)
 
diff --git a/test/functional/lua/ui_event_spec.lua b/test/functional/lua/ui_event_spec.lua
new file mode 100644
index 0000000000..6481da900e
--- /dev/null
+++ b/test/functional/lua/ui_event_spec.lua
@@ -0,0 +1,147 @@
+local helpers = require('test.functional.helpers')(after_each)
+local Screen = require('test.functional.ui.screen')
+local eq = helpers.eq
+local exec_lua = helpers.exec_lua
+local clear = helpers.clear
+local feed = helpers.feed
+local funcs = helpers.funcs
+local inspect = require'vim.inspect'
+
+describe('vim.ui_attach', function()
+  local screen
+  before_each(function()
+    clear()
+    exec_lua [[
+      ns = vim.api.nvim_create_namespace 'testspace'
+      events = {}
+      function on_event(event, ...)
+        events[#events+1] = {event, ...}
+        return true
+      end
+
+      function get_events()
+        local ret_events = events
+        events = {}
+        return ret_events
+      end
+    ]]
+
+    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};
+    })
+    screen:attach()
+  end)
+
+  local function expect_events(expected)
+    local evs = exec_lua "return get_events(...)"
+    eq(expected, evs, inspect(evs))
+  end
+
+  it('can receive popupmenu events', function()
+    exec_lua [[ vim.ui_attach(ns, {ext_popupmenu=true}, on_event) ]]
+    feed('ifo')
+    screen:expect{grid=[[
+      fo^                                      |
+      {1:~                                       }|
+      {1:~                                       }|
+      {1:~                                       }|
+      {2:-- INSERT --}                            |
+    ]]}
+
+    funcs.complete(1, {'food', 'foobar', 'foo'})
+    screen:expect{grid=[[
+      food^                                    |
+      {1:~                                       }|
+      {1:~                                       }|
+      {1:~                                       }|
+      {2:-- INSERT --}                            |
+    ]]}
+    expect_events {
+      { "popupmenu_show", { { "food", "", "", "" }, { "foobar", "", "", "" }, { "foo", "", "", "" } }, 0, 0, 0, 1 };
+    }
+
+    feed '<c-n>'
+    screen:expect{grid=[[
+      foobar^                                  |
+      {1:~                                       }|
+      {1:~                                       }|
+      {1:~                                       }|
+      {2:-- INSERT --}                            |
+    ]]}
+    expect_events {
+       { "popupmenu_select", 1 };
+    }
+
+    feed '<c-y>'
+    screen:expect{grid=[[
+      foobar^                                  |
+      {1:~                                       }|
+      {1:~                                       }|
+      {1:~                                       }|
+      {2:-- INSERT --}                            |
+    ]], intermediate=true}
+    expect_events {
+       { "popupmenu_hide" };
+    }
+
+    -- vim.ui_detach() stops events, and reenables builtin pum immediately
+    exec_lua [[
+      vim.ui_detach(ns)
+      vim.fn.complete(1, {'food', 'foobar', 'foo'})
+    ]]
+
+    screen:expect{grid=[[
+      food^                                    |
+      {3:food           }{1:                         }|
+      {4:foobar         }{1:                         }|
+      {4:foo            }{1:                         }|
+      {2:-- INSERT --}                            |
+    ]]}
+    expect_events {
+    }
+
+  end)
+
+  it('does not crash on exit', function()
+    helpers.funcs.system({
+      helpers.nvim_prog,
+      '-u', 'NONE',
+      '-i', 'NONE',
+      '--cmd', [[ lua ns = vim.api.nvim_create_namespace 'testspace' ]],
+      '--cmd', [[ lua vim.ui_attach(ns, {ext_popupmenu=true}, function() end) ]],
+      '--cmd', 'quitall!',
+    })
+    eq(0, helpers.eval('v:shell_error'))
+  end)
+
+  it('can receive accurate message kinds even if they are history', function()
+    exec_lua([[
+    vim.cmd.echomsg("'message1'")
+    print('message2')
+    vim.ui_attach(ns, { ext_messages = true }, on_event)
+    vim.cmd.echomsg("'message3'")
+    ]])
+    feed(':messages<cr>')
+    feed('<cr>')
+
+    local actual = exec_lua([[
+    return vim.tbl_filter(function (event)
+      return event[1] == "msg_history_show"
+    end, events)
+    ]])
+    eq({
+      {
+        'msg_history_show',
+        {
+          { 'echomsg', { { 0, 'message1' } } },
+          { '', { { 0, 'message2' } } },
+          { 'echomsg', { { 0, 'message3' } } },
+        },
+      },
+    }, actual, inspect(actual))
+  end)
+end)
diff --git a/test/functional/lua/ui_spec.lua b/test/functional/lua/ui_spec.lua
index 3fcb2dec8d..9ee99b4905 100644
--- a/test/functional/lua/ui_spec.lua
+++ b/test/functional/lua/ui_spec.lua
@@ -4,6 +4,7 @@ local exec_lua = helpers.exec_lua
 local clear = helpers.clear
 local feed = helpers.feed
 local eval = helpers.eval
+local poke_eventloop = helpers.poke_eventloop
 
 describe('vim.ui', function()
   before_each(function()
@@ -83,5 +84,50 @@ describe('vim.ui', function()
       feed('abcdefg<cr>')
       eq('abcdefg', exec_lua('return result'))
     end)
+
+    it('can input empty text #18144', function()
+      feed(':lua vim.ui.input({}, function(input) result = input end)<cr>')
+      feed('<cr>')
+      eq('', exec_lua('return result'))
+    end)
+
+    it('can input empty text with cancelreturn opt #18144', function()
+      feed(':lua vim.ui.input({ cancelreturn = "CANCEL" }, function(input) result = input end)<cr>')
+      feed('<cr>')
+      eq('', exec_lua('return result'))
+    end)
+
+    it('can return nil when aborted with ESC #18144', function()
+      feed(':lua result = "on_confirm not called"<cr>')
+      feed(':lua vim.ui.input({}, function(input) result = input end)<cr>')
+      feed('Inputted Text<esc>')
+      -- Note: When `result == nil`, exec_lua('returns result') returns vim.NIL
+      eq(true, exec_lua('return (nil == result)'))
+    end)
+
+    it('can return opts.cacelreturn when aborted with ESC with cancelreturn opt #18144', function()
+      feed(':lua result = "on_confirm not called"<cr>')
+      feed(':lua vim.ui.input({ cancelreturn = "CANCEL" }, function(input) result = input end)<cr>')
+      feed('Inputted Text<esc>')
+      eq('CANCEL', exec_lua('return result'))
+    end)
+
+    it('can return nil when interrupted with Ctrl-C #18144', function()
+      feed(':lua result = "on_confirm not called"<cr>')
+      feed(':lua vim.ui.input({}, function(input) result = input end)<cr>')
+      poke_eventloop()  -- This is needed because Ctrl-C flushes input
+      feed('Inputted Text<c-c>')
+      eq(true, exec_lua('return (nil == result)'))
+    end)
+
+    it('can return the identical object when an arbitrary opts.cancelreturn object is given', function()
+      feed(':lua fn = function() return 42 end<CR>')
+      eq(42, exec_lua('return fn()'))
+      feed(':lua vim.ui.input({ cancelreturn = fn }, function(input) result = input end)<cr>')
+      feed('cancel<esc>')
+      eq(true, exec_lua('return (result == fn)'))
+      eq(42, exec_lua('return result()'))
+    end)
+
   end)
 end)
diff --git a/test/functional/lua/uri_spec.lua b/test/functional/lua/uri_spec.lua
index 4635f17557..416e9e1f02 100644
--- a/test/functional/lua/uri_spec.lua
+++ b/test/functional/lua/uri_spec.lua
@@ -2,6 +2,8 @@ local helpers = require('test.functional.helpers')(after_each)
 local clear = helpers.clear
 local exec_lua = helpers.exec_lua
 local eq = helpers.eq
+local is_os = helpers.is_os
+local skip = helpers.skip
 local write_file = require('test.helpers').write_file
 
 describe('URI methods', function()
@@ -11,7 +13,7 @@ describe('URI methods', function()
 
   describe('file path to uri', function()
     describe('encode Unix file path', function()
-      it('file path includes only ascii charactors', function()
+      it('file path includes only ascii characters', function()
         exec_lua("filepath = '/Foo/Bar/Baz.txt'")
 
         eq('file:///Foo/Bar/Baz.txt', exec_lua("return vim.uri_from_fname(filepath)"))
@@ -23,7 +25,7 @@ describe('URI methods', function()
         eq('file:///Foo%20/Bar/Baz.txt', exec_lua("return vim.uri_from_fname(filepath)"))
       end)
 
-      it('file path including Unicode charactors', function()
+      it('file path including Unicode characters', function()
         exec_lua("filepath = '/xy/åäö/ɧ/汉语/↥/🤦/🦄/å/بِيَّ.txt'")
 
         -- The URI encoding should be case-insensitive
@@ -32,7 +34,7 @@ describe('URI methods', function()
     end)
 
     describe('encode Windows filepath', function()
-      it('file path includes only ascii charactors', function()
+      it('file path includes only ascii characters', function()
         exec_lua([[filepath = 'C:\\Foo\\Bar\\Baz.txt']])
 
         eq('file:///C:/Foo/Bar/Baz.txt', exec_lua("return vim.uri_from_fname(filepath)"))
@@ -44,7 +46,7 @@ describe('URI methods', function()
         eq('file:///C:/Foo%20/Bar/Baz.txt', exec_lua("return vim.uri_from_fname(filepath)"))
       end)
 
-      it('file path including Unicode charactors', function()
+      it('file path including Unicode characters', function()
         exec_lua([[filepath = 'C:\\xy\\åäö\\ɧ\\汉语\\↥\\🤦\\🦄\\å\\بِيَّ.txt']])
 
         eq('file:///C:/xy/%c3%a5%c3%a4%c3%b6/%c9%a7/%e6%b1%89%e8%af%ad/%e2%86%a5/%f0%9f%a4%a6/%f0%9f%a6%84/a%cc%8a/%d8%a8%d9%90%d9%8a%d9%8e%d9%91.txt', exec_lua("return vim.uri_from_fname(filepath)"))
@@ -72,7 +74,7 @@ describe('URI methods', function()
         eq('/Foo /Bar/Baz.txt', exec_lua("return vim.uri_to_fname(uri)"))
       end)
 
-      it('file path including Unicode charactors', function()
+      it('file path including Unicode characters', function()
         local test_case = [[
         local uri = 'file:///xy/%C3%A5%C3%A4%C3%B6/%C9%A7/%E6%B1%89%E8%AF%AD/%E2%86%A5/%F0%9F%A4%A6/%F0%9F%A6%84/a%CC%8A/%D8%A8%D9%90%D9%8A%D9%8E%D9%91.txt'
         return vim.uri_to_fname(uri)
@@ -83,7 +85,7 @@ describe('URI methods', function()
     end)
 
     describe('decode Windows filepath', function()
-      it('file path includes only ascii charactors', function()
+      it('file path includes only ascii characters', function()
         local test_case = [[
         local uri = 'file:///C:/Foo/Bar/Baz.txt'
         return vim.uri_to_fname(uri)
@@ -119,7 +121,7 @@ describe('URI methods', function()
         eq('C:\\Foo \\Bar\\Baz.txt', exec_lua(test_case))
       end)
 
-      it('file path including Unicode charactors', function()
+      it('file path including Unicode characters', function()
         local test_case = [[
         local uri = 'file:///C:/xy/%C3%A5%C3%A4%C3%B6/%C9%A7/%E6%B1%89%E8%AF%AD/%E2%86%A5/%F0%9F%A4%A6/%F0%9F%A6%84/a%CC%8A/%D8%A8%D9%90%D9%8A%D9%8E%D9%91.txt'
         return vim.uri_to_fname(uri)
@@ -167,7 +169,7 @@ describe('URI methods', function()
 
   describe('uri from bufnr', function()
     it('Windows paths should not be treated as uris', function()
-      if not helpers.iswin() then return end
+      skip(not is_os('win'), "Not applicable on non-Windows")
 
       local file = helpers.tmpname()
       write_file(file, 'Test content')
diff --git a/test/functional/lua/vim_spec.lua b/test/functional/lua/vim_spec.lua
index 2b249b7a69..867f366d06 100644
--- a/test/functional/lua/vim_spec.lua
+++ b/test/functional/lua/vim_spec.lua
@@ -2,6 +2,7 @@
 local helpers = require('test.functional.helpers')(after_each)
 local Screen = require('test.functional.ui.screen')
 
+local nvim_prog = helpers.nvim_prog
 local funcs = helpers.funcs
 local meths = helpers.meths
 local command = helpers.command
@@ -22,8 +23,8 @@ local remove_trace = helpers.remove_trace
 local mkdir_p = helpers.mkdir_p
 local rmdir = helpers.rmdir
 local write_file = helpers.write_file
-local expect_exit = helpers.expect_exit
 local poke_eventloop = helpers.poke_eventloop
+local assert_alive = helpers.assert_alive
 
 describe('lua stdlib', function()
   before_each(clear)
@@ -158,28 +159,32 @@ describe('lua stdlib', function()
   end)
 
   it("vim.str_utfindex/str_byteindex", function()
-    exec_lua([[_G.test_text = "xy åäö ɧ 汉语 ↥ 🤦x🦄 å بِيَّ"]])
-    local indicies32 = {[0]=0,1,2,3,5,7,9,10,12,13,16,19,20,23,24,28,29,33,34,35,37,38,40,42,44,46,48}
-    local indicies16 = {[0]=0,1,2,3,5,7,9,10,12,13,16,19,20,23,24,28,28,29,33,33,34,35,37,38,40,42,44,46,48}
-    for i,k in pairs(indicies32) do
+    exec_lua([[_G.test_text = "xy åäö ɧ 汉语 ↥ 🤦x🦄 å بِيَّ\000ъ"]])
+    local indices32 = {[0]=0,1,2,3,5,7,9,10,12,13,16,19,20,23,24,28,29,33,34,35,37,38,40,42,44,46,48,49,51}
+    local indices16 = {[0]=0,1,2,3,5,7,9,10,12,13,16,19,20,23,24,28,28,29,33,33,34,35,37,38,40,42,44,46,48,49,51}
+    for i,k in pairs(indices32) do
       eq(k, exec_lua("return vim.str_byteindex(_G.test_text, ...)", i), i)
     end
-    for i,k in pairs(indicies16) do
+    for i,k in pairs(indices16) do
       eq(k, exec_lua("return vim.str_byteindex(_G.test_text, ..., true)", i), i)
     end
+    eq("index out of range", pcall_err(exec_lua, "return vim.str_byteindex(_G.test_text, ...)", #indices32 + 1))
+    eq("index out of range", pcall_err(exec_lua, "return vim.str_byteindex(_G.test_text, ..., true)", #indices16 + 1))
     local i32, i16 = 0, 0
-    for k = 0,48 do
-      if indicies32[i32] < k then
+    local len = 51
+    for k = 0,len do
+      if indices32[i32] < k then
         i32 = i32 + 1
       end
-      if indicies16[i16] < k then
+      if indices16[i16] < k then
         i16 = i16 + 1
-        if indicies16[i16+1] == indicies16[i16] then
+        if indices16[i16+1] == indices16[i16] then
           i16 = i16 + 1
         end
       end
       eq({i32, i16}, exec_lua("return {vim.str_utfindex(_G.test_text, ...)}", k), k)
     end
+    eq("index out of range", pcall_err(exec_lua, "return vim.str_utfindex(_G.test_text, ...)", len + 1))
   end)
 
   it("vim.str_utf_start", function()
@@ -414,6 +419,12 @@ describe('lua stdlib', function()
       return getmetatable(t2) == mt
     ]]))
 
+    ok(exec_lua([[
+      local t1 = {a = vim.NIL}
+      local t2 = vim.deepcopy(t1)
+      return t2.a == vim.NIL
+    ]]))
+
     matches('Cannot deepcopy object of type thread',
       pcall_err(exec_lua, [[
         local thread = coroutine.create(function () return 0 end)
@@ -425,6 +436,8 @@ describe('lua stdlib', function()
   it('vim.pesc', function()
     eq('foo%-bar', exec_lua([[return vim.pesc('foo-bar')]]))
     eq('foo%%%-bar', exec_lua([[return vim.pesc(vim.pesc('foo-bar'))]]))
+    -- pesc() returns one result. #20751
+    eq({'x'}, exec_lua([[return {vim.pesc('x')}]]))
 
     -- Validates args.
     matches('s: expected string, got number',
@@ -499,6 +512,8 @@ describe('lua stdlib', function()
     eq(NIL, exec_lua("return vim.tbl_get({ unindexable = function () end }, 'unindexable', 'missing_key')"))
     eq(NIL, exec_lua("return vim.tbl_get({}, 'missing_key')"))
     eq(NIL, exec_lua("return vim.tbl_get({})"))
+    eq(1, exec_lua("return select('#', vim.tbl_get({}))"))
+    eq(1, exec_lua("return select('#', vim.tbl_get({ nested = {} }, 'nested', 'missing_key'))"))
   end)
 
   it('vim.tbl_extend', function()
@@ -748,6 +763,20 @@ describe('lua stdlib', function()
       pcall_err(exec_lua, code))
   end)
 
+  it('vim.spairs', function()
+    local res = ''
+    local table = {
+      ccc=1,
+      bbb=2,
+      ddd=3,
+      aaa=4
+    }
+    for key, _ in vim.spairs(table) do
+      res = res .. key
+    end
+    matches('aaabbbcccddd', res)
+  end)
+
   it('vim.call, vim.fn', function()
     eq(true, exec_lua([[return vim.call('sin', 0.0) == 0.0 ]]))
     eq(true, exec_lua([[return vim.fn.sin(0.0) == 0.0 ]]))
@@ -788,6 +817,11 @@ describe('lua stdlib', function()
       local x = vim.fn.VarArg(function() return 'foo' end, function() return 'bar' end)
       return #x == 2 and x[1]() == 'foo' and x[2]() == 'bar'
     ]]))
+
+    -- Test for #20211
+    eq('a (b) c', exec_lua([[
+      return vim.fn.substitute('a b c', 'b', function(m) return '(' .. m[1] .. ')' end, 'g')
+    ]]))
   end)
 
   it('vim.fn should error when calling API function', function()
@@ -896,7 +930,7 @@ describe('lua stdlib', function()
     ]]))
 
     -- vim.empty_dict() gives new value each time
-    -- equality is not overriden (still by ref)
+    -- equality is not overridden (still by ref)
     -- non-empty table uses the usual heuristics (ignores the tag)
     eq({false, {"foo"}, {namey="bar"}}, exec_lua([[
       local aa = vim.empty_dict()
@@ -1006,11 +1040,11 @@ describe('lua stdlib', function()
     eq('hi', funcs.luaeval "vim.g.testing")
     eq(123, funcs.luaeval "vim.g.other")
     eq(5120.1, funcs.luaeval "vim.g.floaty")
-    eq(NIL, funcs.luaeval "vim.g.nonexistant")
+    eq(NIL, funcs.luaeval "vim.g.nonexistent")
     eq(NIL, funcs.luaeval "vim.g.nullvar")
     -- lost over RPC, so test locally:
     eq({false, true}, exec_lua [[
-      return {vim.g.nonexistant == vim.NIL, vim.g.nullvar == vim.NIL}
+      return {vim.g.nonexistent == vim.NIL, vim.g.nullvar == vim.NIL}
     ]])
 
     eq({hello="world"}, funcs.luaeval "vim.g.to_delete")
@@ -1029,6 +1063,7 @@ describe('lua stdlib', function()
       vim.g.AddCounter = add_counter
       vim.g.GetCounter = get_counter
       vim.g.funcs = {add = add_counter, get = get_counter}
+      vim.g.AddParens = function(s) return '(' .. s .. ')' end
     ]]
 
     eq(0, eval('g:GetCounter()'))
@@ -1044,6 +1079,7 @@ describe('lua stdlib', function()
     eq(5, exec_lua([[return vim.g.funcs.get()]]))
     exec_lua([[vim.api.nvim_get_var('funcs').add()]])
     eq(6, exec_lua([[return vim.api.nvim_get_var('funcs').get()]]))
+    eq('((foo))', eval([['foo'->AddParens()->AddParens()]]))
 
     exec_lua [[
       local counter = 0
@@ -1052,6 +1088,7 @@ describe('lua stdlib', function()
       vim.api.nvim_set_var('AddCounter', add_counter)
       vim.api.nvim_set_var('GetCounter', get_counter)
       vim.api.nvim_set_var('funcs', {add = add_counter, get = get_counter})
+      vim.api.nvim_set_var('AddParens', function(s) return '(' .. s .. ')' end)
     ]]
 
     eq(0, eval('g:GetCounter()'))
@@ -1067,6 +1104,7 @@ describe('lua stdlib', function()
     eq(5, exec_lua([[return vim.g.funcs.get()]]))
     exec_lua([[vim.api.nvim_get_var('funcs').add()]])
     eq(6, exec_lua([[return vim.api.nvim_get_var('funcs').get()]]))
+    eq('((foo))', eval([['foo'->AddParens()->AddParens()]]))
 
     exec([[
       function Test()
@@ -1109,12 +1147,12 @@ describe('lua stdlib', function()
     eq('bye', funcs.luaeval "vim.b[BUF].testing")
     eq(123, funcs.luaeval "vim.b.other")
     eq(5120.1, funcs.luaeval "vim.b.floaty")
-    eq(NIL, funcs.luaeval "vim.b.nonexistant")
-    eq(NIL, funcs.luaeval "vim.b[BUF].nonexistant")
+    eq(NIL, funcs.luaeval "vim.b.nonexistent")
+    eq(NIL, funcs.luaeval "vim.b[BUF].nonexistent")
     eq(NIL, funcs.luaeval "vim.b.nullvar")
     -- lost over RPC, so test locally:
     eq({false, true}, exec_lua [[
-      return {vim.b.nonexistant == vim.NIL, vim.b.nullvar == vim.NIL}
+      return {vim.b.nonexistent == vim.NIL, vim.b.nullvar == vim.NIL}
     ]])
 
     matches([[attempt to index .* nil value]],
@@ -1133,6 +1171,7 @@ describe('lua stdlib', function()
       vim.b.AddCounter = add_counter
       vim.b.GetCounter = get_counter
       vim.b.funcs = {add = add_counter, get = get_counter}
+      vim.b.AddParens = function(s) return '(' .. s .. ')' end
     ]]
 
     eq(0, eval('b:GetCounter()'))
@@ -1148,6 +1187,7 @@ describe('lua stdlib', function()
     eq(5, exec_lua([[return vim.b.funcs.get()]]))
     exec_lua([[vim.api.nvim_buf_get_var(0, 'funcs').add()]])
     eq(6, exec_lua([[return vim.api.nvim_buf_get_var(0, 'funcs').get()]]))
+    eq('((foo))', eval([['foo'->b:AddParens()->b:AddParens()]]))
 
     exec_lua [[
       local counter = 0
@@ -1156,6 +1196,7 @@ describe('lua stdlib', function()
       vim.api.nvim_buf_set_var(0, 'AddCounter', add_counter)
       vim.api.nvim_buf_set_var(0, 'GetCounter', get_counter)
       vim.api.nvim_buf_set_var(0, 'funcs', {add = add_counter, get = get_counter})
+      vim.api.nvim_buf_set_var(0, 'AddParens', function(s) return '(' .. s .. ')' end)
     ]]
 
     eq(0, eval('b:GetCounter()'))
@@ -1171,6 +1212,7 @@ describe('lua stdlib', function()
     eq(5, exec_lua([[return vim.b.funcs.get()]]))
     exec_lua([[vim.api.nvim_buf_get_var(0, 'funcs').add()]])
     eq(6, exec_lua([[return vim.api.nvim_buf_get_var(0, 'funcs').get()]]))
+    eq('((foo))', eval([['foo'->b:AddParens()->b:AddParens()]]))
 
     exec([[
       function Test()
@@ -1189,7 +1231,7 @@ describe('lua stdlib', function()
 
     eq(NIL, funcs.luaeval "vim.b.testing")
     eq(NIL, funcs.luaeval "vim.b.other")
-    eq(NIL, funcs.luaeval "vim.b.nonexistant")
+    eq(NIL, funcs.luaeval "vim.b.nonexistent")
   end)
 
   it('vim.w', function()
@@ -1208,8 +1250,8 @@ describe('lua stdlib', function()
     eq('hi', funcs.luaeval "vim.w.testing")
     eq('bye', funcs.luaeval "vim.w[WIN].testing")
     eq(123, funcs.luaeval "vim.w.other")
-    eq(NIL, funcs.luaeval "vim.w.nonexistant")
-    eq(NIL, funcs.luaeval "vim.w[WIN].nonexistant")
+    eq(NIL, funcs.luaeval "vim.w.nonexistent")
+    eq(NIL, funcs.luaeval "vim.w[WIN].nonexistent")
 
     matches([[attempt to index .* nil value]],
        pcall_err(exec_lua, 'return vim.w[WIN][0].testing'))
@@ -1227,6 +1269,7 @@ describe('lua stdlib', function()
       vim.w.AddCounter = add_counter
       vim.w.GetCounter = get_counter
       vim.w.funcs = {add = add_counter, get = get_counter}
+      vim.w.AddParens = function(s) return '(' .. s .. ')' end
     ]]
 
     eq(0, eval('w:GetCounter()'))
@@ -1242,6 +1285,7 @@ describe('lua stdlib', function()
     eq(5, exec_lua([[return vim.w.funcs.get()]]))
     exec_lua([[vim.api.nvim_win_get_var(0, 'funcs').add()]])
     eq(6, exec_lua([[return vim.api.nvim_win_get_var(0, 'funcs').get()]]))
+    eq('((foo))', eval([['foo'->w:AddParens()->w:AddParens()]]))
 
     exec_lua [[
       local counter = 0
@@ -1250,6 +1294,7 @@ describe('lua stdlib', function()
       vim.api.nvim_win_set_var(0, 'AddCounter', add_counter)
       vim.api.nvim_win_set_var(0, 'GetCounter', get_counter)
       vim.api.nvim_win_set_var(0, 'funcs', {add = add_counter, get = get_counter})
+      vim.api.nvim_win_set_var(0, 'AddParens', function(s) return '(' .. s .. ')' end)
     ]]
 
     eq(0, eval('w:GetCounter()'))
@@ -1265,6 +1310,7 @@ describe('lua stdlib', function()
     eq(5, exec_lua([[return vim.w.funcs.get()]]))
     exec_lua([[vim.api.nvim_win_get_var(0, 'funcs').add()]])
     eq(6, exec_lua([[return vim.api.nvim_win_get_var(0, 'funcs').get()]]))
+    eq('((foo))', eval([['foo'->w:AddParens()->w:AddParens()]]))
 
     exec([[
       function Test()
@@ -1283,7 +1329,7 @@ describe('lua stdlib', function()
 
     eq(NIL, funcs.luaeval "vim.w.testing")
     eq(NIL, funcs.luaeval "vim.w.other")
-    eq(NIL, funcs.luaeval "vim.w.nonexistant")
+    eq(NIL, funcs.luaeval "vim.w.nonexistent")
   end)
 
   it('vim.t', function()
@@ -1295,10 +1341,10 @@ describe('lua stdlib', function()
 
     eq('hi', funcs.luaeval "vim.t.testing")
     eq(123, funcs.luaeval "vim.t.other")
-    eq(NIL, funcs.luaeval "vim.t.nonexistant")
+    eq(NIL, funcs.luaeval "vim.t.nonexistent")
     eq('hi', funcs.luaeval "vim.t[0].testing")
     eq(123, funcs.luaeval "vim.t[0].other")
-    eq(NIL, funcs.luaeval "vim.t[0].nonexistant")
+    eq(NIL, funcs.luaeval "vim.t[0].nonexistent")
 
     matches([[attempt to index .* nil value]],
        pcall_err(exec_lua, 'return vim.t[0][0].testing'))
@@ -1316,6 +1362,7 @@ describe('lua stdlib', function()
       vim.t.AddCounter = add_counter
       vim.t.GetCounter = get_counter
       vim.t.funcs = {add = add_counter, get = get_counter}
+      vim.t.AddParens = function(s) return '(' .. s .. ')' end
     ]]
 
     eq(0, eval('t:GetCounter()'))
@@ -1331,6 +1378,7 @@ describe('lua stdlib', function()
     eq(5, exec_lua([[return vim.t.funcs.get()]]))
     exec_lua([[vim.api.nvim_tabpage_get_var(0, 'funcs').add()]])
     eq(6, exec_lua([[return vim.api.nvim_tabpage_get_var(0, 'funcs').get()]]))
+    eq('((foo))', eval([['foo'->t:AddParens()->t:AddParens()]]))
 
     exec_lua [[
       local counter = 0
@@ -1339,6 +1387,7 @@ describe('lua stdlib', function()
       vim.api.nvim_tabpage_set_var(0, 'AddCounter', add_counter)
       vim.api.nvim_tabpage_set_var(0, 'GetCounter', get_counter)
       vim.api.nvim_tabpage_set_var(0, 'funcs', {add = add_counter, get = get_counter})
+      vim.api.nvim_tabpage_set_var(0, 'AddParens', function(s) return '(' .. s .. ')' end)
     ]]
 
     eq(0, eval('t:GetCounter()'))
@@ -1354,6 +1403,7 @@ describe('lua stdlib', function()
     eq(5, exec_lua([[return vim.t.funcs.get()]]))
     exec_lua([[vim.api.nvim_tabpage_get_var(0, 'funcs').add()]])
     eq(6, exec_lua([[return vim.api.nvim_tabpage_get_var(0, 'funcs').get()]]))
+    eq('((foo))', eval([['foo'->t:AddParens()->t:AddParens()]]))
 
     exec_lua [[
     vim.cmd "tabnew"
@@ -1361,15 +1411,27 @@ describe('lua stdlib', function()
 
     eq(NIL, funcs.luaeval "vim.t.testing")
     eq(NIL, funcs.luaeval "vim.t.other")
-    eq(NIL, funcs.luaeval "vim.t.nonexistant")
+    eq(NIL, funcs.luaeval "vim.t.nonexistent")
   end)
 
   it('vim.env', function()
-    exec_lua [[
-    vim.fn.setenv("A", 123)
-    ]]
-    eq('123', funcs.luaeval "vim.env.A")
-    eq(true, funcs.luaeval "vim.env.B == nil")
+    exec_lua([[vim.fn.setenv('A', 123)]])
+    eq('123', funcs.luaeval('vim.env.A'))
+    exec_lua([[vim.env.A = 456]])
+    eq('456', funcs.luaeval('vim.env.A'))
+    exec_lua([[vim.env.A = nil]])
+    eq(NIL, funcs.luaeval('vim.env.A'))
+
+    eq(true, funcs.luaeval('vim.env.B == nil'))
+
+    command([[let $HOME = 'foo']])
+    eq('foo', funcs.expand('~'))
+    eq('foo', funcs.luaeval('vim.env.HOME'))
+    exec_lua([[vim.env.HOME = nil]])
+    eq('foo', funcs.expand('~'))
+    exec_lua([[vim.env.HOME = 'bar']])
+    eq('bar', funcs.expand('~'))
+    eq('bar', funcs.luaeval('vim.env.HOME'))
   end)
 
   it('vim.v', function()
@@ -1396,7 +1458,7 @@ describe('lua stdlib', function()
     ]]
     eq('', funcs.luaeval "vim.bo.filetype")
     eq(true, funcs.luaeval "vim.bo[BUF].modifiable")
-    matches("unknown option 'nosuchopt'$",
+    matches("no such option: 'nosuchopt'$",
        pcall_err(exec_lua, 'return vim.bo.nosuchopt'))
     matches("Expected lua string$",
        pcall_err(exec_lua, 'return vim.bo[0][0].autoread'))
@@ -1417,7 +1479,7 @@ describe('lua stdlib', function()
     eq(0, funcs.luaeval "vim.wo.cole")
     eq(0, funcs.luaeval "vim.wo[0].cole")
     eq(0, funcs.luaeval "vim.wo[1001].cole")
-    matches("unknown option 'notanopt'$",
+    matches("no such option: 'notanopt'$",
        pcall_err(exec_lua, 'return vim.wo.notanopt'))
     matches("Expected lua string$",
        pcall_err(exec_lua, 'return vim.wo[0][0].list'))
@@ -2141,6 +2203,22 @@ describe('lua stdlib', function()
     end)
   end) -- vim.opt
 
+  describe('opt_local', function()
+    it('should be able to append to an array list type option', function()
+      eq({ "foo,bar,baz,qux" }, exec_lua [[
+        local result = {}
+
+        vim.opt.tags = "foo,bar"
+        vim.opt_local.tags:append("baz")
+        vim.opt_local.tags:append("qux")
+
+        table.insert(result, vim.bo.tags)
+
+        return result
+      ]])
+    end)
+  end)
+
   it('vim.cmd', function()
     exec_lua [[
     vim.cmd "autocmd BufNew * ++once lua BUF = vim.fn.expand('<abuf>')"
@@ -2173,6 +2251,10 @@ describe('lua stdlib', function()
     eq({3,7}, exec_lua[[return {re1:match_line(0, 1, 1, 8)}]])
     eq({}, exec_lua[[return {re1:match_line(0, 1, 1, 7)}]])
     eq({0,3}, exec_lua[[return {re1:match_line(0, 1, 0, 7)}]])
+
+    -- vim.regex() error inside :silent! should not crash. #20546
+    command([[silent! lua vim.regex('\\z')]])
+    assert_alive()
   end)
 
   it('vim.defer_fn', function()
@@ -2185,13 +2267,19 @@ describe('lua stdlib', function()
     eq(true, exec_lua[[return vim.g.test]])
   end)
 
-  it('vim.region', function()
-    insert(helpers.dedent( [[
-    text tααt tααt text
-    text tαxt txtα tex
-    text tαxt tαxt
-    ]]))
-    eq({5,15}, exec_lua[[ return vim.region(0,{1,5},{1,14},'v',true)[1] ]])
+  describe('vim.region', function()
+    it('charwise', function()
+      insert(helpers.dedent( [[
+      text tααt tααt text
+      text tαxt txtα tex
+      text tαxt tαxt
+      ]]))
+      eq({5,15}, exec_lua[[ return vim.region(0,{1,5},{1,14},'v',true)[1] ]])
+    end)
+    it('blockwise', function()
+      insert([[αα]])
+      eq({0,5}, exec_lua[[ return vim.region(0,{0,0},{0,4},'3',true)[0] ]])
+    end)
   end)
 
   describe('vim.on_key', function()
@@ -2623,6 +2711,46 @@ describe('lua stdlib', function()
         a.nvim_buf_call(a.nvim_create_buf(false, true), function() vim.cmd "redraw" end)
       ]]
     end)
+
+    it('can be nested crazily with hidden buffers', function()
+      eq(true, exec_lua([[
+        local function scratch_buf_call(fn)
+          local buf = vim.api.nvim_create_buf(false, true)
+          vim.api.nvim_buf_set_option(buf, 'cindent', true)
+          return vim.api.nvim_buf_call(buf, function()
+            return vim.api.nvim_get_current_buf() == buf
+              and vim.api.nvim_buf_get_option(buf, 'cindent')
+              and fn()
+          end) and vim.api.nvim_buf_delete(buf, {}) == nil
+        end
+
+        return scratch_buf_call(function()
+          return scratch_buf_call(function()
+            return scratch_buf_call(function()
+              return scratch_buf_call(function()
+                return scratch_buf_call(function()
+                  return scratch_buf_call(function()
+                    return scratch_buf_call(function()
+                      return scratch_buf_call(function()
+                        return scratch_buf_call(function()
+                          return scratch_buf_call(function()
+                            return scratch_buf_call(function()
+                              return scratch_buf_call(function()
+                                return true
+                              end)
+                            end)
+                          end)
+                        end)
+                      end)
+                    end)
+                  end)
+                end)
+              end)
+            end)
+          end)
+        end)
+      ]]))
+    end)
   end)
 
   describe('vim.api.nvim_win_call', function()
@@ -2721,6 +2849,57 @@ describe('lua stdlib', function()
       ]]
     end)
   end)
+
+  describe('vim.iconv', function()
+    it('can convert strings', function()
+      eq('hello', exec_lua[[
+        return vim.iconv('hello', 'latin1', 'utf-8')
+      ]])
+    end)
+
+    it('can validate arguments', function()
+      eq({false, 'Expected at least 3 arguments'}, exec_lua[[
+        return {pcall(vim.iconv, 'hello')}
+      ]])
+
+      eq({false, 'bad argument #3 to \'?\' (expected string)'}, exec_lua[[
+        return {pcall(vim.iconv, 'hello', 'utf-8', true)}
+      ]])
+    end)
+
+    it('can handle bad encodings', function()
+      eq(NIL, exec_lua[[
+        return vim.iconv('hello', 'foo', 'bar')
+      ]])
+    end)
+
+    it('can handle strings with NUL bytes', function()
+      eq(7, exec_lua[[
+        local a = string.char(97, 98, 99, 0, 100, 101, 102) -- abc\0def
+        return string.len(vim.iconv(a, 'latin1', 'utf-8'))
+      ]])
+    end)
+
+  end)
+
+  describe("vim.defaulttable", function()
+    it("creates nested table by default", function()
+      eq({ b = {c = 1 } }, exec_lua[[
+        local a = vim.defaulttable()
+        a.b.c = 1
+        return a
+      ]])
+    end)
+
+    it("allows to create default objects", function()
+      eq({ b = 1 }, exec_lua[[
+        local a = vim.defaulttable(function() return 0 end)
+        a.b = a.b + 1
+        return a
+      ]])
+    end)
+  end)
+
 end)
 
 describe('lua: builtin modules', function()
@@ -2745,9 +2924,14 @@ describe('lua: builtin modules', function()
   end)
 
 
-  it('does not work when disabled without runtime', function()
-    clear{args={'--luamod-dev'}, env={VIMRUNTIME='fixtures/a'}}
-    expect_exit(exec_lua, [[return vim.tbl_count {x=1,y=2}]])
+  it('fails when disabled without runtime', function()
+    clear()
+    command("let $VIMRUNTIME='fixtures/a'")
+    -- Use system([nvim,…]) instead of clear() to avoid stderr noise. #21844
+    local out = funcs.system({nvim_prog, '--clean', '--luamod-dev',
+      [[+call nvim_exec_lua('return vim.tbl_count {x=1,y=2}')]], '+qa!'}):gsub('\r\n', '\n')
+    eq(1, eval('v:shell_error'))
+    matches("'vim%.shared' not found", out)
   end)
 end)
 
diff --git a/test/functional/lua/xdiff_spec.lua b/test/functional/lua/xdiff_spec.lua
index d55268fc78..3121ac051f 100644
--- a/test/functional/lua/xdiff_spec.lua
+++ b/test/functional/lua/xdiff_spec.lua
@@ -74,11 +74,13 @@ describe('xdiff bindings', function()
     end)
 
     it('with error callback', function()
-      exec_lua([[on_hunk = function(sa, ca, sb, cb)
+      exec_lua[[
+        on_hunk = function(sa, ca, sb, cb)
           error('ERROR1')
-        end]])
+        end
+      ]]
 
-      eq([[Error executing lua: [string "<nvim>"]:0: error running function on_hunk: [string "<nvim>"]:0: ERROR1]],
+      eq([[error running function on_hunk: [string "<nvim>"]:0: ERROR1]],
         pcall_err(exec_lua, [[vim.diff(a1, b1, {on_hunk = on_hunk})]]))
     end)
 
@@ -135,19 +137,19 @@ describe('xdiff bindings', function()
   end)
 
   it('can handle bad args', function()
-    eq([[Error executing lua: [string "<nvim>"]:0: Expected at least 2 arguments]],
+    eq([[Expected at least 2 arguments]],
       pcall_err(exec_lua, [[vim.diff('a')]]))
 
-    eq([[Error executing lua: [string "<nvim>"]:0: bad argument #1 to 'diff' (expected string)]],
+    eq([[bad argument #1 to 'diff' (expected string)]],
       pcall_err(exec_lua, [[vim.diff(1, 2)]]))
 
-    eq([[Error executing lua: [string "<nvim>"]:0: bad argument #3 to 'diff' (expected table)]],
+    eq([[bad argument #3 to 'diff' (expected table)]],
       pcall_err(exec_lua, [[vim.diff('a', 'b', true)]]))
 
-    eq([[Error executing lua: [string "<nvim>"]:0: unexpected key: bad_key]],
+    eq([[unexpected key: bad_key]],
       pcall_err(exec_lua, [[vim.diff('a', 'b', { bad_key = true })]]))
 
-    eq([[Error executing lua: [string "<nvim>"]:0: on_hunk is not a function]],
+    eq([[on_hunk is not a function]],
       pcall_err(exec_lua, [[vim.diff('a', 'b', { on_hunk = true })]]))
 
   end)