UIEnter/UILeave: fire for embedder UI, builtin TUI

Before this, --embed UIs (without --headless) would not trigger UIEnter.

For TUI, maybe UIEnter isn't useful, but:
- It is less "surprising"/special.
- Makes documentation simpler.
- When TUI becomes a coprocess, it will happen anyway.

2 files changed, 34 insertions, 7 deletions

diff --git a/test/functional/api/ui_spec.lua b/test/functional/api/ui_spec.lua
index c5c3185eff..279cd1856d 100644
--- a/test/functional/api/ui_spec.lua
+++ b/test/functional/api/ui_spec.lua
@@ -37,12 +37,14 @@ describe('nvim_ui_attach()', function()
 end)
 
 it('autocmds UIEnter/UILeave', function()
-  clear{args={
-    '--cmd', 'let g:evs = []',
-    '--cmd', 'autocmd UIEnter * :call add(g:evs, "UIEnter") | let g:uienter_ev = deepcopy(v:event)',
-    '--cmd', 'autocmd UILeave * :call add(g:evs, "UILeave") | let g:uileave_ev = deepcopy(v:event)',
-    '--cmd', 'autocmd VimEnter * :call add(g:evs, "VimEnter")',
-  }}
+  clear{
+    args_rm={'--headless'},
+    args={
+      '--cmd', 'let g:evs = []',
+      '--cmd', 'autocmd UIEnter * :call add(g:evs, "UIEnter") | let g:uienter_ev = deepcopy(v:event)',
+      '--cmd', 'autocmd UILeave * :call add(g:evs, "UILeave") | let g:uileave_ev = deepcopy(v:event)',
+      '--cmd', 'autocmd VimEnter * :call add(g:evs, "VimEnter")',
+    }}
   local screen = Screen.new()
   screen:attach()
   eq({chan=1}, eval('g:uienter_ev'))
diff --git a/test/functional/terminal/tui_spec.lua b/test/functional/terminal/tui_spec.lua
index 725a6db225..c55093cb0f 100644
--- a/test/functional/terminal/tui_spec.lua
+++ b/test/functional/terminal/tui_spec.lua
@@ -767,11 +767,36 @@ describe('TUI', function()
   end)
 end)
 
+describe('TUI UIEnter/UILeave', function()
+  it('fires exactly once, after VimEnter', function()
+    clear()
+    local screen = thelpers.screen_setup(0,
+      '["'..nvim_prog..'", "-u", "NONE", "-i", "NONE"'
+      ..[[, "--cmd", "set noswapfile noshowcmd noruler"]]
+      ..[[, "--cmd", "let g:evs = []"]]
+      ..[[, "--cmd", "autocmd UIEnter  * :call add(g:evs, 'UIEnter')"]]
+      ..[[, "--cmd", "autocmd UILeave  * :call add(g:evs, 'UILeave')"]]
+      ..[[, "--cmd", "autocmd VimEnter * :call add(g:evs, 'VimEnter')"]]
+      ..']'
+    )
+    feed_data(":echo g:evs\n")
+    screen:expect{grid=[[
+      {1: }                                                 |
+      {4:~                                                 }|
+      {4:~                                                 }|
+      {4:~                                                 }|
+      {5:[No Name]                                         }|
+      ['VimEnter', 'UIEnter']                           |
+      {3:-- TERMINAL --}                                    |
+    ]]}
+  end)
+end)
+
 describe('TUI FocusGained/FocusLost', function()
   local screen
 
   before_each(function()
-    helpers.clear()
+    clear()
     screen = thelpers.screen_setup(0, '["'..nvim_prog
       ..'", "-u", "NONE", "-i", "NONE", "--cmd", "set noswapfile noshowcmd noruler"]')
     feed_data(":autocmd FocusGained * echo 'gained'\n")