test: use exec_capture() in more places (#22787)

Problem:
Using `meths.exec2("code", { output = true })` is too verbose.

Solution:
Use exec_capture() in more places.

2 files changed, 8 insertions, 6 deletions

diff --git a/test/functional/ui/cmdline_highlight_spec.lua b/test/functional/ui/cmdline_highlight_spec.lua
index d6c8408f04..783246c6e4 100644
--- a/test/functional/ui/cmdline_highlight_spec.lua
+++ b/test/functional/ui/cmdline_highlight_spec.lua
@@ -7,6 +7,7 @@ local clear = helpers.clear
 local meths = helpers.meths
 local funcs = helpers.funcs
 local source = helpers.source
+local exec_capture = helpers.exec_capture
 local dedent = helpers.dedent
 local command = helpers.command
 local curbufmeths = helpers.curbufmeths
@@ -362,7 +363,7 @@ describe('Command-line coloring', function()
       {EOB:~                                       }|
       :e^                                      |
     ]])
-    eq('', meths.exec2('messages', { output = true }).output)
+    eq('', exec_capture('messages'))
   end)
   it('silences :echon', function()
     set_color_cb('Echoning')
@@ -377,7 +378,7 @@ describe('Command-line coloring', function()
       {EOB:~                                       }|
       :e^                                      |
     ]])
-    eq('', meths.exec2('messages', { output = true }).output)
+    eq('', exec_capture('messages'))
   end)
   it('silences :echomsg', function()
     set_color_cb('Echomsging')
@@ -392,7 +393,7 @@ describe('Command-line coloring', function()
       {EOB:~                                       }|
       :e^                                      |
     ]])
-    eq('', meths.exec2('messages', { output = true }).output)
+    eq('', exec_capture('messages'))
   end)
   it('does the right thing when throwing', function()
     set_color_cb('Throwing')
@@ -858,7 +859,7 @@ describe('Ex commands coloring', function()
     ]])
     feed('<CR>')
     eq('Error detected while processing :\nE605: Exception not caught: 42\nE749: empty buffer',
-       meths.exec2('messages', { output = true }).output)
+       exec_capture('messages'))
   end)
   it('errors out when failing to get callback', function()
     meths.set_var('Nvim_color_cmdline', 42)
diff --git a/test/functional/ui/messages_spec.lua b/test/functional/ui/messages_spec.lua
index 81602ef92e..5220f3fa89 100644
--- a/test/functional/ui/messages_spec.lua
+++ b/test/functional/ui/messages_spec.lua
@@ -10,6 +10,7 @@ local async_meths = helpers.async_meths
 local test_build_dir = helpers.test_build_dir
 local nvim_prog = helpers.nvim_prog
 local exec = helpers.exec
+local exec_capture = helpers.exec_capture
 local exc_exec = helpers.exc_exec
 local exec_lua = helpers.exec_lua
 local poke_eventloop = helpers.poke_eventloop
@@ -986,7 +987,7 @@ describe('ui/builtin messages', function()
 
     -- screen size doesn't affect internal output #10285
     eq('ErrorMsg       xxx ctermfg=15 ctermbg=1 guifg=White guibg=Red',
-       meths.exec2("hi ErrorMsg", { output = true }).output)
+       exec_capture("hi ErrorMsg"))
   end)
 
   it(':syntax list langGroup output', function()
@@ -1025,7 +1026,7 @@ vimComment     xxx match /\s"[^\-:.%#=*].*$/ms=s+1,lc=1  excludenl contains=@vim
                    match /\<endif\s\+".*$/ms=s+5,lc=5  contains=@vimCommentGroup,vimCommentString 
                    match /\<else\s\+".*$/ms=s+4,lc=4  contains=@vimCommentGroup,vimCommentString 
                    links to Comment]],
-       meths.exec2('syntax list vimComment', { output = true }).output)
+       exec_capture('syntax list vimComment'))
     -- luacheck: pop
   end)