feat: add completion to ':lua'

2 files changed, 208 insertions, 1 deletions

diff --git a/test/functional/lua/command_line_completion_spec.lua b/test/functional/lua/command_line_completion_spec.lua
new file mode 100644
index 0000000000..9056f80fb5
--- /dev/null
+++ b/test/functional/lua/command_line_completion_spec.lua
@@ -0,0 +1,167 @@
+local helpers = require('test.functional.helpers')(after_each)
+
+local clear = helpers.clear
+local eq = helpers.eq
+local funcs = helpers.funcs
+local exec_lua = helpers.exec_lua
+
+local get_completions = function(input, env)
+  return exec_lua("return vim._expand_pat(...)", '^' .. input, env)
+end
+
+local get_compl_parts = function(parts)
+  return funcs.luaeval("{vim._expand_pat_get_parts(_A)}", parts)
+end
+
+before_each(clear)
+
+describe('nlua_expand_pat', function()
+  it('should complete exact matches', function()
+    eq({'exact'}, get_completions('exact', { exact = true }))
+  end)
+
+  it('should return empty table when nothing matches', function()
+    eq({}, get_completions('foo', { bar = true }))
+  end)
+
+  it('should return nice completions with function call prefix', function()
+    eq({'print(FOO'}, get_completions('print(F', { FOO = true, bawr = true }))
+  end)
+
+  it('should return keys for nested dictionaries', function()
+    eq(
+      {
+        'vim.api.nvim_buf_set_lines',
+        'vim.api.nvim_buf_set_option'
+      },
+      get_completions('vim.api.nvim_buf_', {
+        vim = {
+          api = {
+            nvim_buf_set_lines = true,
+            nvim_buf_set_option = true,
+            nvim_win_doesnt_match = true,
+          },
+          other_key = true,
+        }
+      })
+    )
+  end)
+
+  it('it should work with colons', function()
+    eq(
+      {
+        'MyClass:bawr',
+        'MyClass:baz',
+      },
+      get_completions('MyClass:b', {
+        MyClass = {
+          baz = true,
+          bawr = true,
+          foo = false,
+        }
+      })
+    )
+  end)
+
+  it('should return keys for string reffed dictionaries', function()
+    eq(
+      {
+        'vim["api"].nvim_buf_set_lines',
+        'vim["api"].nvim_buf_set_option'
+      },
+      get_completions('vim["api"].nvim_buf_', {
+        vim = {
+          api = {
+            nvim_buf_set_lines = true,
+            nvim_buf_set_option = true,
+            nvim_win_doesnt_match = true,
+          },
+          other_key = true,
+        }
+      })
+    )
+  end)
+
+  it('should return keys for string reffed dictionaries', function()
+    eq(
+      {
+        'vim["nested"]["api"].nvim_buf_set_lines',
+        'vim["nested"]["api"].nvim_buf_set_option'
+      },
+      get_completions('vim["nested"]["api"].nvim_buf_', {
+        vim = {
+          nested = {
+            api = {
+              nvim_buf_set_lines = true,
+              nvim_buf_set_option = true,
+              nvim_win_doesnt_match = true,
+            },
+          },
+          other_key = true,
+        }
+      })
+    )
+  end)
+
+  it('should be able to interpolate globals', function()
+    eq(
+      {
+        'vim[MY_VAR].nvim_buf_set_lines',
+        'vim[MY_VAR].nvim_buf_set_option'
+      },
+      get_completions('vim[MY_VAR].nvim_buf_', {
+        MY_VAR = "api",
+        vim = {
+          api = {
+            nvim_buf_set_lines = true,
+            nvim_buf_set_option = true,
+            nvim_win_doesnt_match = true,
+          },
+          other_key = true,
+        }
+      })
+    )
+  end)
+
+  it('should return everything if the input is of length 0', function()
+    eq({"other", "vim"}, get_completions('', { vim = true, other = true }))
+  end)
+
+  describe('get_parts', function()
+    it('should return an empty list for no separators', function()
+      eq({{}, 1}, get_compl_parts("vim"))
+    end)
+
+    it('just the first item before a period', function()
+      eq({{"vim"}, 5}, get_compl_parts("vim.ap"))
+    end)
+
+    it('should return multiple parts just for period', function()
+      eq({{"vim", "api"}, 9}, get_compl_parts("vim.api.nvim_buf"))
+    end)
+
+    it('should be OK with colons', function()
+      eq({{"vim", "api"}, 9}, get_compl_parts("vim:api.nvim_buf"))
+    end)
+
+    it('should work for just one string ref', function()
+      eq({{"vim", "api"}, 12}, get_compl_parts("vim['api'].nvim_buf"))
+    end)
+
+    it('should work for just one string ref, with double quote', function()
+      eq({{"vim", "api"}, 12}, get_compl_parts('vim["api"].nvim_buf'))
+    end)
+
+    it('should allows back-to-back string ref', function()
+      eq({{"vim", "nested", "api"}, 22}, get_compl_parts('vim["nested"]["api"].nvim_buf'))
+    end)
+
+    it('should allows back-to-back string ref with spaces before and after', function()
+      eq({{"vim", "nested", "api"}, 25}, get_compl_parts('vim[ "nested"  ]["api"].nvim_buf'))
+    end)
+
+    it('should allow VAR style loolup', function()
+      eq({{"vim", {"NESTED"}, "api"}, 20}, get_compl_parts('vim[NESTED]["api"].nvim_buf'))
+    end)
+  end)
+end)
diff --git a/test/functional/viml/completion_spec.lua b/test/functional/viml/completion_spec.lua
index 01fc50289d..d59a1a3306 100644
--- a/test/functional/viml/completion_spec.lua
+++ b/test/functional/viml/completion_spec.lua
@@ -26,6 +26,7 @@ describe('completion', function()
       [7] = {foreground = Screen.colors.White, background = Screen.colors.Red},
       [8] = {reverse = true},
       [9] = {bold = true, reverse = true},
+      [10] = {foreground = Screen.colors.Grey0, background = Screen.colors.Yellow},
     })
   end)
 
@@ -895,8 +896,47 @@ describe('completion', function()
     ]])
   end)
 
-  describe('from the commandline window', function()
+  describe('lua completion', function()
+    it('expands when there is only one match', function()
+      feed(':lua CURRENT_TESTING_VAR = 1<CR>')
+      feed(':lua CURRENT_TESTING_<TAB>')
+      screen:expect{grid=[[
+                                                                    |
+        {0:~                                                           }|
+        {0:~                                                           }|
+        {0:~                                                           }|
+        {0:~                                                           }|
+        {0:~                                                           }|
+        {0:~                                                           }|
+        :lua CURRENT_TESTING_VAR^                                    |
+      ]]}
+    end)
 
+    it('expands when there is only one match', function()
+      feed(':lua CURRENT_TESTING_FOO = 1<CR>')
+      feed(':lua CURRENT_TESTING_BAR = 1<CR>')
+      feed(':lua CURRENT_TESTING_<TAB>')
+      screen:expect{ grid = [[
+                                                                    |
+        {0:~                                                           }|
+        {0:~                                                           }|
+        {0:~                                                           }|
+        {0:~                                                           }|
+        {0:~                                                           }|
+        {10:CURRENT_TESTING_BAR}{9:  CURRENT_TESTING_FOO                    }|
+        :lua CURRENT_TESTING_BAR^                                    |
+      ]], unchanged = true }
+    end)
+
+    it('provides completion from `getcompletion()`', function()
+      eq({'vim'}, meths.call_function('getcompletion', {'vi', 'lua'}))
+      eq({'vim.api'}, meths.call_function('getcompletion', {'vim.ap', 'lua'}))
+      eq({'vim.tbl_filter'}, meths.call_function('getcompletion', {'vim.tbl_fil', 'lua'}))
+      eq({'print(vim'}, meths.call_function('getcompletion', {'print(vi', 'lua'}))
+    end)
+  end)
+
+  describe('from the commandline window', function()
     it('is cleared after CTRL-C', function ()
       feed('q:')
       feed('ifoo faa fee f')