Add v:lua.func() vimL syntax for calling lua

Also simplify error messages when calling lua from vimL.

4 files changed, 169 insertions, 83 deletions

diff --git a/test/functional/lua/api_spec.lua b/test/functional/lua/api_spec.lua
index b1dc5c07fd..23167d3ed9 100644
--- a/test/functional/lua/api_spec.lua
+++ b/test/functional/lua/api_spec.lua
@@ -155,41 +155,41 @@ describe('luaeval(vim.api.…)', function()
 
   it('errors out correctly when working with API', function()
     -- Conversion errors
-    eq('Vim(call):E5108: Error while calling lua chunk for luaeval(): [string "<VimL compiled string>"]:1: Cannot convert given lua type',
+    eq('Vim(call):E5108: Error executing lua [string "luaeval()"]:1: Cannot convert given lua type',
        exc_exec([[call luaeval("vim.api.nvim__id(vim.api.nvim__id)")]]))
-    eq('Vim(call):E5108: Error while calling lua chunk for luaeval(): [string "<VimL compiled string>"]:1: Cannot convert given lua table',
+    eq('Vim(call):E5108: Error executing lua [string "luaeval()"]:1: Cannot convert given lua table',
        exc_exec([[call luaeval("vim.api.nvim__id({1, foo=42})")]]))
-    eq('Vim(call):E5108: Error while calling lua chunk for luaeval(): [string "<VimL compiled string>"]:1: Cannot convert given lua type',
+    eq('Vim(call):E5108: Error executing lua [string "luaeval()"]:1: Cannot convert given lua type',
        exc_exec([[call luaeval("vim.api.nvim__id({42, vim.api.nvim__id})")]]))
     -- Errors in number of arguments
-    eq('Vim(call):E5108: Error while calling lua chunk for luaeval(): [string "<VimL compiled string>"]:1: Expected 1 argument',
+    eq('Vim(call):E5108: Error executing lua [string "luaeval()"]:1: Expected 1 argument',
        exc_exec([[call luaeval("vim.api.nvim__id()")]]))
-    eq('Vim(call):E5108: Error while calling lua chunk for luaeval(): [string "<VimL compiled string>"]:1: Expected 1 argument',
+    eq('Vim(call):E5108: Error executing lua [string "luaeval()"]:1: Expected 1 argument',
        exc_exec([[call luaeval("vim.api.nvim__id(1, 2)")]]))
-    eq('Vim(call):E5108: Error while calling lua chunk for luaeval(): [string "<VimL compiled string>"]:1: Expected 2 arguments',
+    eq('Vim(call):E5108: Error executing lua [string "luaeval()"]:1: Expected 2 arguments',
        exc_exec([[call luaeval("vim.api.nvim_set_var(1, 2, 3)")]]))
     -- Error in argument types
-    eq('Vim(call):E5108: Error while calling lua chunk for luaeval(): [string "<VimL compiled string>"]:1: Expected lua string',
+    eq('Vim(call):E5108: Error executing lua [string "luaeval()"]:1: Expected lua string',
        exc_exec([[call luaeval("vim.api.nvim_set_var(1, 2)")]]))
 
-    eq('Vim(call):E5108: Error while calling lua chunk for luaeval(): [string "<VimL compiled string>"]:1: Expected lua number',
+    eq('Vim(call):E5108: Error executing lua [string "luaeval()"]:1: Expected lua number',
        exc_exec([[call luaeval("vim.api.nvim_buf_get_lines(0, 'test', 1, false)")]]))
-    eq('Vim(call):E5108: Error while calling lua chunk for luaeval(): [string "<VimL compiled string>"]:1: Number is not integral',
+    eq('Vim(call):E5108: Error executing lua [string "luaeval()"]:1: Number is not integral',
        exc_exec([[call luaeval("vim.api.nvim_buf_get_lines(0, 1.5, 1, false)")]]))
 
-    eq('Vim(call):E5108: Error while calling lua chunk for luaeval(): [string "<VimL compiled string>"]:1: Expected lua table',
+    eq('Vim(call):E5108: Error executing lua [string "luaeval()"]:1: Expected lua table',
        exc_exec([[call luaeval("vim.api.nvim__id_float('test')")]]))
-    eq('Vim(call):E5108: Error while calling lua chunk for luaeval(): [string "<VimL compiled string>"]:1: Unexpected type',
+    eq('Vim(call):E5108: Error executing lua [string "luaeval()"]:1: Unexpected type',
        exc_exec([[call luaeval("vim.api.nvim__id_float({[vim.type_idx]=vim.types.dictionary})")]]))
 
-    eq('Vim(call):E5108: Error while calling lua chunk for luaeval(): [string "<VimL compiled string>"]:1: Expected lua table',
+    eq('Vim(call):E5108: Error executing lua [string "luaeval()"]:1: Expected lua table',
        exc_exec([[call luaeval("vim.api.nvim__id_array(1)")]]))
-    eq('Vim(call):E5108: Error while calling lua chunk for luaeval(): [string "<VimL compiled string>"]:1: Unexpected type',
+    eq('Vim(call):E5108: Error executing lua [string "luaeval()"]:1: Unexpected type',
        exc_exec([[call luaeval("vim.api.nvim__id_array({[vim.type_idx]=vim.types.dictionary})")]]))
 
-    eq('Vim(call):E5108: Error while calling lua chunk for luaeval(): [string "<VimL compiled string>"]:1: Expected lua table',
+    eq('Vim(call):E5108: Error executing lua [string "luaeval()"]:1: Expected lua table',
        exc_exec([[call luaeval("vim.api.nvim__id_dictionary(1)")]]))
-    eq('Vim(call):E5108: Error while calling lua chunk for luaeval(): [string "<VimL compiled string>"]:1: Unexpected type',
+    eq('Vim(call):E5108: Error executing lua [string "luaeval()"]:1: Unexpected type',
        exc_exec([[call luaeval("vim.api.nvim__id_dictionary({[vim.type_idx]=vim.types.array})")]]))
     -- TODO: check for errors with Tabpage argument
     -- TODO: check for errors with Window argument
diff --git a/test/functional/lua/commands_spec.lua b/test/functional/lua/commands_spec.lua
index 26dcbe0534..96eaa7991b 100644
--- a/test/functional/lua/commands_spec.lua
+++ b/test/functional/lua/commands_spec.lua
@@ -13,6 +13,7 @@ local source = helpers.source
 local dedent = helpers.dedent
 local command = helpers.command
 local exc_exec = helpers.exc_exec
+local pcall_err = helpers.pcall_err
 local write_file = helpers.write_file
 local redir_exec = helpers.redir_exec
 local curbufmeths = helpers.curbufmeths
@@ -42,16 +43,16 @@ describe(':lua command', function()
     eq({'', 'ETTS', 'TTSE', 'STTE'}, curbufmeths.get_lines(0, 100, false))
   end)
   it('throws catchable errors', function()
-    eq([[Vim(lua):E5104: Error while creating lua chunk: [string "<VimL compiled string>"]:1: unexpected symbol near ')']],
-       exc_exec('lua ()'))
-    eq([[Vim(lua):E5105: Error while calling lua chunk: [string "<VimL compiled string>"]:1: TEST]],
+    eq([[Vim(lua):E5107: Error loading lua [string ":lua"]:1: unexpected symbol near ')']],
+       pcall_err(command, 'lua ()'))
+    eq([[Vim(lua):E5108: Error executing lua [string ":lua"]:1: TEST]],
        exc_exec('lua error("TEST")'))
-    eq([[Vim(lua):E5105: Error while calling lua chunk: [string "<VimL compiled string>"]:1: Invalid buffer id]],
+    eq([[Vim(lua):E5108: Error executing lua [string ":lua"]:1: Invalid buffer id]],
        exc_exec('lua vim.api.nvim_buf_set_lines(-10, 1, 1, false, {"TEST"})'))
     eq({''}, curbufmeths.get_lines(0, 100, false))
   end)
   it('works with NULL errors', function()
-    eq([=[Vim(lua):E5105: Error while calling lua chunk: [NULL]]=],
+    eq([=[Vim(lua):E5108: Error executing lua [NULL]]=],
        exc_exec('lua error(nil)'))
   end)
   it('accepts embedded NLs without heredoc', function()
@@ -74,7 +75,7 @@ describe(':lua command', function()
   it('works with long strings', function()
     local s = ('x'):rep(100500)
 
-    eq('\nE5104: Error while creating lua chunk: [string "<VimL compiled string>"]:1: unfinished string near \'<eof>\'', redir_exec(('lua vim.api.nvim_buf_set_lines(1, 1, 2, false, {"%s})'):format(s)))
+    eq('\nE5107: Error loading lua [string ":lua"]:1: unfinished string near \'<eof>\'', redir_exec(('lua vim.api.nvim_buf_set_lines(1, 1, 2, false, {"%s})'):format(s)))
     eq({''}, curbufmeths.get_lines(0, -1, false))
 
     eq('', redir_exec(('lua vim.api.nvim_buf_set_lines(1, 1, 2, false, {"%s"})'):format(s)))
@@ -82,7 +83,7 @@ describe(':lua command', function()
   end)
 
   it('can show multiline error messages', function()
-    local screen = Screen.new(50,10)
+    local screen = Screen.new(40,10)
     screen:attach()
     screen:set_default_attr_ids({
       [1] = {bold = true, foreground = Screen.colors.Blue1},
@@ -92,51 +93,51 @@ describe(':lua command', function()
     })
 
     feed(':lua error("fail\\nmuch error\\nsuch details")<cr>')
-    screen:expect([[
-                                                        |
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {2:                                                  }|
-      {3:E5105: Error while calling lua chunk: [string "<Vi}|
-      {3:mL compiled string>"]:1: fail}                     |
-      {3:much error}                                        |
-      {3:such details}                                      |
-      {4:Press ENTER or type command to continue}^           |
-    ]])
+    screen:expect{grid=[[
+                                              |
+      {1:~                                       }|
+      {1:~                                       }|
+      {1:~                                       }|
+      {2:                                        }|
+      {3:E5108: Error executing lua [string ":lua}|
+      {3:"]:1: fail}                              |
+      {3:much error}                              |
+      {3:such details}                            |
+      {4:Press ENTER or type command to continue}^ |
+    ]]}
     feed('<cr>')
-    screen:expect([[
-      ^                                                  |
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-                                                        |
-    ]])
-    eq('E5105: Error while calling lua chunk: [string "<VimL compiled string>"]:1: fail\nmuch error\nsuch details', eval('v:errmsg'))
+    screen:expect{grid=[[
+      ^                                        |
+      {1:~                                       }|
+      {1:~                                       }|
+      {1:~                                       }|
+      {1:~                                       }|
+      {1:~                                       }|
+      {1:~                                       }|
+      {1:~                                       }|
+      {1:~                                       }|
+                                              |
+    ]]}
+    eq('E5108: Error executing lua [string ":lua"]:1: fail\nmuch error\nsuch details', eval('v:errmsg'))
 
     local status, err = pcall(command,'lua error("some error\\nin a\\nAPI command")')
-    local expected = 'Vim(lua):E5105: Error while calling lua chunk: [string "<VimL compiled string>"]:1: some error\nin a\nAPI command'
+    local expected = 'Vim(lua):E5108: Error executing lua [string ":lua"]:1: some error\nin a\nAPI command'
     eq(false, status)
     eq(expected, string.sub(err, -string.len(expected)))
 
     feed(':messages<cr>')
-    screen:expect([[
-                                                        |
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {2:                                                  }|
-      {3:E5105: Error while calling lua chunk: [string "<Vi}|
-      {3:mL compiled string>"]:1: fail}                     |
-      {3:much error}                                        |
-      {3:such details}                                      |
-      {4:Press ENTER or type command to continue}^           |
-    ]])
+    screen:expect{grid=[[
+                                              |
+      {1:~                                       }|
+      {1:~                                       }|
+      {1:~                                       }|
+      {2:                                        }|
+      {3:E5108: Error executing lua [string ":lua}|
+      {3:"]:1: fail}                              |
+      {3:much error}                              |
+      {3:such details}                            |
+      {4:Press ENTER or type command to continue}^ |
+    ]]}
   end)
 end)
 
@@ -167,13 +168,13 @@ describe(':luado command', function()
     eq({''}, curbufmeths.get_lines(0, -1, false))
   end)
   it('fails on errors', function()
-    eq([[Vim(luado):E5109: Error while creating lua chunk: [string "<VimL compiled string>"]:1: unexpected symbol near ')']],
+    eq([[Vim(luado):E5109: Error loading lua: [string ":luado"]:1: unexpected symbol near ')']],
        exc_exec('luado ()'))
-    eq([[Vim(luado):E5111: Error while calling lua function: [string "<VimL compiled string>"]:1: attempt to perform arithmetic on global 'liness' (a nil value)]],
+    eq([[Vim(luado):E5111: Error calling lua: [string ":luado"]:1: attempt to perform arithmetic on global 'liness' (a nil value)]],
        exc_exec('luado return liness + 1'))
   end)
   it('works with NULL errors', function()
-    eq([=[Vim(luado):E5111: Error while calling lua function: [NULL]]=],
+    eq([=[Vim(luado):E5111: Error calling lua: [NULL]]=],
        exc_exec('luado error(nil)'))
   end)
   it('fails in sandbox when needed', function()
@@ -185,7 +186,7 @@ describe(':luado command', function()
   it('works with long strings', function()
     local s = ('x'):rep(100500)
 
-    eq('\nE5109: Error while creating lua chunk: [string "<VimL compiled string>"]:1: unfinished string near \'<eof>\'', redir_exec(('luado return "%s'):format(s)))
+    eq('\nE5109: Error loading lua: [string ":luado"]:1: unfinished string near \'<eof>\'', redir_exec(('luado return "%s'):format(s)))
     eq({''}, curbufmeths.get_lines(0, -1, false))
 
     eq('', redir_exec(('luado return "%s"'):format(s)))
diff --git a/test/functional/lua/luaeval_spec.lua b/test/functional/lua/luaeval_spec.lua
index 760105df6b..61c8e5c02e 100644
--- a/test/functional/lua/luaeval_spec.lua
+++ b/test/functional/lua/luaeval_spec.lua
@@ -1,13 +1,17 @@
 -- Test suite for testing luaeval() function
 local helpers = require('test.functional.helpers')(after_each)
+local Screen = require('test.functional.ui.screen')
 
 local redir_exec = helpers.redir_exec
+local pcall_err = helpers.pcall_err
 local exc_exec = helpers.exc_exec
+local exec_lua = helpers.exec_lua
 local command = helpers.command
 local meths = helpers.meths
 local funcs = helpers.funcs
 local clear = helpers.clear
 local eval = helpers.eval
+local feed = helpers.feed
 local NIL = helpers.NIL
 local eq = helpers.eq
 
@@ -186,9 +190,9 @@ describe('luaeval()', function()
        exc_exec('call luaeval("{1, foo=2}")'))
     eq("Vim(call):E5101: Cannot convert given lua type",
        exc_exec('call luaeval("vim.api.nvim_buf_get_lines")'))
-    startswith("Vim(call):E5107: Error while creating lua chunk for luaeval(): ",
+    startswith("Vim(call):E5107: Error loading lua [string \"luaeval()\"]:",
                exc_exec('call luaeval("1, 2, 3")'))
-    startswith("Vim(call):E5108: Error while calling lua chunk for luaeval(): ",
+    startswith("Vim(call):E5108: Error executing lua [string \"luaeval()\"]:",
                exc_exec('call luaeval("(nil)()")'))
     eq("Vim(call):E5101: Cannot convert given lua type",
        exc_exec('call luaeval("{42, vim.api}")'))
@@ -237,19 +241,99 @@ describe('luaeval()', function()
 
   it('errors out correctly when doing incorrect things in lua', function()
     -- Conversion errors
-    eq('Vim(call):E5108: Error while calling lua chunk for luaeval(): [string "<VimL compiled string>"]:1: attempt to call field \'xxx_nonexistent_key_xxx\' (a nil value)',
+    eq('Vim(call):E5108: Error executing lua [string "luaeval()"]:1: attempt to call field \'xxx_nonexistent_key_xxx\' (a nil value)',
        exc_exec([[call luaeval("vim.xxx_nonexistent_key_xxx()")]]))
-    eq('Vim(call):E5108: Error while calling lua chunk for luaeval(): [string "<VimL compiled string>"]:1: ERROR',
+    eq('Vim(call):E5108: Error executing lua [string "luaeval()"]:1: ERROR',
        exc_exec([[call luaeval("error('ERROR')")]]))
-    eq('Vim(call):E5108: Error while calling lua chunk for luaeval(): [NULL]',
+    eq('Vim(call):E5108: Error executing lua [NULL]',
        exc_exec([[call luaeval("error(nil)")]]))
   end)
 
   it('does not leak memory when called with too long line',
   function()
     local s = ('x'):rep(65536)
-    eq('Vim(call):E5107: Error while creating lua chunk for luaeval(): [string "<VimL compiled string>"]:1: unexpected symbol near \')\'',
+    eq('Vim(call):E5107: Error loading lua [string "luaeval()"]:1: unexpected symbol near \')\'',
        exc_exec([[call luaeval("(']] .. s ..[[' + )")]]))
     eq(s, funcs.luaeval('"' .. s .. '"'))
   end)
 end)
+
+describe('v:lua', function()
+  before_each(function()
+    exec_lua([[
+      function _G.foo(a,b,n)
+        _G.val = n
+        return a+b
+      end
+      mymod = {}
+      function mymod.noisy(name)
+        vim.api.nvim_set_current_line("hey "..name)
+      end
+      function mymod.crashy()
+        nonexistent()
+      end
+      function mymod.omni(findstart, base)
+        if findstart == 1 then
+          return 5
+        else
+          if base == 'st' then
+            return {'stuff', 'steam', 'strange things'}
+          end
+        end
+      end
+      vim.api.nvim_buf_set_option(0, 'omnifunc', 'v:lua.mymod.omni')
+    ]])
+  end)
+
+  it('works in expressions', function()
+    eq(7, eval('v:lua.foo(3,4,v:null)'))
+    eq(true, exec_lua([[return _G.val == vim.NIL]]))
+    eq(NIL, eval('v:lua.mymod.noisy("eval")'))
+    eq("hey eval", meths.get_current_line())
+
+    eq("Vim:E5108: Error executing lua [string \"<nvim>\"]:10: attempt to call global 'nonexistent' (a nil value)",
+       pcall_err(eval, 'v:lua.mymod.crashy()'))
+  end)
+
+  it('works in :call', function()
+    command(":call v:lua.mymod.noisy('command')")
+    eq("hey command", meths.get_current_line())
+    eq("Vim(call):E5108: Error executing lua [string \"<nvim>\"]:10: attempt to call global 'nonexistent' (a nil value)",
+       pcall_err(command, 'call v:lua.mymod.crashy()'))
+  end)
+
+  it('works in func options', function()
+    local screen = Screen.new(60, 8)
+    screen:set_default_attr_ids({
+      [1] = {bold = true, foreground = Screen.colors.Blue1},
+      [2] = {background = Screen.colors.WebGray},
+      [3] = {background = Screen.colors.LightMagenta},
+      [4] = {bold = true},
+      [5] = {bold = true, foreground = Screen.colors.SeaGreen4},
+    })
+    screen:attach()
+    feed('isome st<c-x><c-o>')
+    screen:expect{grid=[[
+      some stuff^                                                  |
+      {1:~   }{2: stuff          }{1:                                        }|
+      {1:~   }{3: steam          }{1:                                        }|
+      {1:~   }{3: strange things }{1:                                        }|
+      {1:~                                                           }|
+      {1:~                                                           }|
+      {1:~                                                           }|
+      {4:-- Omni completion (^O^N^P) }{5:match 1 of 3}                    |
+    ]]}
+  end)
+
+  it('throw errors for invalid use', function()
+    eq('Vim(let):E15: Invalid expression: v:lua.func', pcall_err(command, "let g:Func = v:lua.func"))
+    eq('Vim(let):E15: Invalid expression: v:lua', pcall_err(command, "let g:Func = v:lua"))
+    eq("Vim(let):E15: Invalid expression: v:['lua']", pcall_err(command, "let g:Func = v:['lua']"))
+
+    eq("Vim:E15: Invalid expression: v:['lua'].foo()", pcall_err(eval, "v:['lua'].foo()"))
+    eq("Vim(call):E461: Illegal variable name: v:['lua']", pcall_err(command, "call v:['lua'].baar()"))
+
+    eq("Vim(let):E46: Cannot change read-only variable \"v:['lua']\"", pcall_err(command, "let v:['lua'] = 'xx'"))
+    eq("Vim(let):E46: Cannot change read-only variable \"v:lua\"", pcall_err(command, "let v:lua = 'xx'"))
+  end)
+end)
diff --git a/test/functional/lua/overrides_spec.lua b/test/functional/lua/overrides_spec.lua
index f6439001ac..8c260632d9 100644
--- a/test/functional/lua/overrides_spec.lua
+++ b/test/functional/lua/overrides_spec.lua
@@ -54,11 +54,12 @@ describe('print', function()
       v_tblout = setmetatable({}, meta_tblout)
     ]])
     eq('', redir_exec('luafile ' .. fname))
-    eq('\nE5105: Error while calling lua chunk: E5114: Error while converting print argument #2: [NULL]',
+    -- TODO(bfredl): these look weird, print() should not use "E5114:" style errors..
+    eq('\nE5108: Error executing lua E5114: Error while converting print argument #2: [NULL]',
        redir_exec('lua print("foo", v_nilerr, "bar")'))
-    eq('\nE5105: Error while calling lua chunk: E5114: Error while converting print argument #2: Xtest-functional-lua-overrides-luafile:2: abc',
+    eq('\nE5108: Error executing lua E5114: Error while converting print argument #2: Xtest-functional-lua-overrides-luafile:2: abc',
        redir_exec('lua print("foo", v_abcerr, "bar")'))
-    eq('\nE5105: Error while calling lua chunk: E5114: Error while converting print argument #2: <Unknown error: lua_tolstring returned NULL for tostring result>',
+    eq('\nE5108: Error executing lua E5114: Error while converting print argument #2: <Unknown error: lua_tolstring returned NULL for tostring result>',
        redir_exec('lua print("foo", v_tblout, "bar")'))
   end)
   it('prints strings with NULs and NLs correctly', function()
@@ -156,7 +157,8 @@ describe('debug.debug', function()
       lua_debug> ^                                          |
     ]])
     feed('<C-c>')
-    screen:expect([[
+    screen:expect{grid=[[
+      {0:~                                                    }|
       {0:~                                                    }|
       {0:~                                                    }|
       {0:~                                                    }|
@@ -167,11 +169,10 @@ describe('debug.debug', function()
       lua_debug> print("TEST")                             |
       TEST                                                 |
                                                            |
-      {E:E5105: Error while calling lua chunk: [string "<VimL }|
-      {E:compiled string>"]:5: attempt to perform arithmetic o}|
-      {E:n local 'a' (a nil value)}                            |
+      {E:E5108: Error executing lua [string ":lua"]:5: attempt}|
+      {E: to perform arithmetic on local 'a' (a nil value)}    |
       Interrupt: {cr:Press ENTER or type command to continue}^   |
-    ]])
+    ]]}
     feed('<C-l>:lua Test()\n')
     screen:expect([[
       {0:~                                                    }|
@@ -190,7 +191,8 @@ describe('debug.debug', function()
       lua_debug> ^                                          |
     ]])
     feed('\n')
-    screen:expect([[
+    screen:expect{grid=[[
+      {0:~                                                    }|
       {0:~                                                    }|
       {0:~                                                    }|
       {0:~                                                    }|
@@ -201,11 +203,10 @@ describe('debug.debug', function()
       {0:~                                                    }|
       nil                                                  |
       lua_debug>                                           |
-      {E:E5105: Error while calling lua chunk: [string "<VimL }|
-      {E:compiled string>"]:5: attempt to perform arithmetic o}|
-      {E:n local 'a' (a nil value)}                            |
+      {E:E5108: Error executing lua [string ":lua"]:5: attempt}|
+      {E: to perform arithmetic on local 'a' (a nil value)}    |
       {cr:Press ENTER or type command to continue}^              |
-    ]])
+    ]]}
   end)
 
   it("can be safely exited with 'cont'", function()