fix(tests): needing two calls to setup a screen is cringe

Before calling "attach" a screen object is just a dummy container for
(row, col) values whose purpose is to be sent as part of the "attach"
function call anyway.

Just create the screen in an attached state directly. Keep the complete
(row, col, options) config together. It is still completely valid to
later detach and re-attach as needed, including to another session.

1 files changed, 38 insertions, 51 deletions

diff --git a/test/functional/ui/screen.lua b/test/functional/ui/screen.lua
index 358e54dc55..8e15e6c35f 100644
--- a/test/functional/ui/screen.lua
+++ b/test/functional/ui/screen.lua
@@ -6,23 +6,15 @@
 --
 -- Example usage:
 --
+--     -- Attach a screen to the current Nvim instance.
 --     local screen = Screen.new(25, 10)
---     -- Attach the screen to the current Nvim instance.
---     screen:attach()
 --     -- Enter insert-mode and type some text.
 --     feed('ihello screen')
 --     -- Assert the expected screen state.
 --     screen:expect([[
---       hello screen             |
---       ~                        |
---       ~                        |
---       ~                        |
---       ~                        |
---       ~                        |
---       ~                        |
---       ~                        |
---       ~                        |
---       -- INSERT --             |
+--       hello screen^             |
+--       {1:~                        }|*8
+--       {5:-- INSERT --}             |
 --     ]]) -- <- Last line is stripped
 --
 -- Since screen updates are received asynchronously, expect() actually specifies
@@ -36,36 +28,19 @@
 --    * If the timeout expires, the last match error will be reported and the
 --      test will fail.
 --
--- Continuing the above example, say we want to assert that "-- INSERT --" is
--- highlighted with the bold attribute. The expect() call should look like this:
---
---     NonText = Screen.colors.Blue
---     screen:expect([[
---       hello screen             |
---       ~                        |
---       ~                        |
---       ~                        |
---       ~                        |
---       ~                        |
---       ~                        |
---       ~                        |
---       ~                        |
---       {b:-- INSERT --}             |
---     ]], {b = {bold = true}}, {{bold = true, foreground = NonText}})
---
--- In this case "b" is a string associated with the set composed of one
--- attribute: bold. Note that since the {b:} markup is not a real part of the
+-- The 30 most common highlight groups are predefined, see init_colors() below.
+-- In this case "5" is a predefined highlight associated with the set composed of one
+-- attribute: bold. Note that since the {5:} markup is not a real part of the
 -- screen, the delimiter "|" moved to the right. Also, the highlighting of the
--- NonText markers "~" is ignored in this test.
+-- NonText markers "~" is visible.
 --
--- Tests will often share a group of attribute sets to expect(). Those can be
+-- Tests will often share a group of extra attribute sets to expect(). Those can be
 -- defined at the beginning of a test:
 --
---    NonText = Screen.colors.Blue
---    screen:set_default_attr_ids( {
---      [1] = {reverse = true, bold = true},
---      [2] = {reverse = true}
---    })
+--    screen:add_extra_attr_ids {
+--      [100] = { background = Screen.colors.Plum1, underline = true },
+--      [101] = { background = Screen.colors.Red1, bold = true, underline = true },
+--    }
 --
 -- To help write screen tests, see Screen:snapshot_util().
 -- To debug screen tests, see Screen:redraw_debug().
@@ -180,14 +155,30 @@ local function _init_colors()
   }
 end
 
+--- @class test.functional.ui.screen.Opts
+--- @field ext_linegrid? boolean
+--- @field ext_multigrid? boolean
+--- @field ext_newgrid? boolean
+--- @field ext_popupmenu? boolean
+--- @field ext_wildmenu? boolean
+--- @field rgb? boolean
+--- @field _debug_float? boolean
+
 --- @param width? integer
 --- @param height? integer
+--- @param options? test.functional.ui.screen.Opts
+--- @param session? test.Session|false
 --- @return test.functional.ui.screen
-function Screen.new(width, height)
+function Screen.new(width, height, options, session)
   if not Screen.colors then
     _init_colors()
   end
 
+  options = options or {}
+  if options.ext_linegrid == nil then
+    options.ext_linegrid = true
+  end
+
   local self = setmetatable({
     timeout = default_screen_timeout,
     title = '',
@@ -227,6 +218,7 @@ function Screen.new(width, height)
     _new_attrs = false,
     _width = width or 53,
     _height = height or 14,
+    _options = options,
     _grids = {},
     _grid_win_extmarks = {},
     _cursor = {
@@ -250,6 +242,11 @@ function Screen.new(width, height)
 
   self.uimeths = create_callindex(ui)
 
+  -- session is often nil, which implies the default session
+  if session ~= false then
+    self:attach(session)
+  end
+
   return self
 end
 
@@ -277,20 +274,10 @@ function Screen:set_rgb_cterm(val)
   self._rgb_cterm = val
 end
 
---- @class test.functional.ui.screen.Opts
---- @field ext_linegrid? boolean
---- @field ext_multigrid? boolean
---- @field ext_newgrid? boolean
---- @field ext_popupmenu? boolean
---- @field ext_wildmenu? boolean
---- @field rgb? boolean
---- @field _debug_float? boolean
-
---- @param options? test.functional.ui.screen.Opts
 --- @param session? test.Session
-function Screen:attach(options, session)
+function Screen:attach(session)
   session = session or get_session()
-  options = options or {}
+  local options = self._options
 
   if options.ext_linegrid == nil then
     options.ext_linegrid = true