refactor(tests): remove redir_exec #15718

Problem
- `redir_exec` is obsolete, but it keeps getting used in new tests
  because people copy existing tests.
- Disadvantages of `redir_exec`:
  - Captures extra junk before the actual error/message that we _want_ to test.
  - Does not fail on error, unlike e.g. `command()`.

Solution
- Use new functions like `nvim_exec` and `pcall_err`.

1 files changed, 14 insertions, 16 deletions

diff --git a/test/functional/vimscript/minmax_functions_spec.lua b/test/functional/vimscript/minmax_functions_spec.lua
index c6eb754f91..91106bef1e 100644
--- a/test/functional/vimscript/minmax_functions_spec.lua
+++ b/test/functional/vimscript/minmax_functions_spec.lua
@@ -2,29 +2,28 @@ local helpers = require('test.functional.helpers')(after_each)
 
 local eq = helpers.eq
 local eval = helpers.eval
+local command = helpers.command
 local clear = helpers.clear
 local funcs = helpers.funcs
-local redir_exec = helpers.redir_exec
+local pcall_err = helpers.pcall_err
 
 before_each(clear)
 for _, func in ipairs({'min', 'max'}) do
   describe(func .. '()', function()
     it('gives a single error message when multiple values failed conversions',
     function()
-      eq('\nE745: Using a List as a Number\n0',
-         redir_exec('echo ' .. func .. '([-5, [], [], [], 5])'))
-      eq('\nE745: Using a List as a Number\n0',
-         redir_exec('echo ' .. func .. '({1:-5, 2:[], 3:[], 4:[], 5:5})'))
+      eq('Vim(echo):E745: Using a List as a Number',
+         pcall_err(command, 'echo ' .. func .. '([-5, [], [], [], 5])'))
+      eq('Vim(echo):E745: Using a List as a Number',
+         pcall_err(command, 'echo ' .. func .. '({1:-5, 2:[], 3:[], 4:[], 5:5})'))
       for errmsg, errinput in pairs({
-        ['E745: Using a List as a Number'] = '[]',
-        ['E805: Using a Float as a Number'] = '0.0',
-        ['E703: Using a Funcref as a Number'] = 'function("tr")',
-        ['E728: Using a Dictionary as a Number'] = '{}',
+        ['Vim(echo):E745: Using a List as a Number'] = '[]',
+        ['Vim(echo):E805: Using a Float as a Number'] = '0.0',
+        ['Vim(echo):E703: Using a Funcref as a Number'] = 'function("tr")',
+        ['Vim(echo):E728: Using a Dictionary as a Number'] = '{}',
       }) do
-        eq('\n' .. errmsg .. '\n0',
-           redir_exec('echo ' .. func .. '([' .. errinput .. '])'))
-        eq('\n' .. errmsg .. '\n0',
-           redir_exec('echo ' .. func .. '({1:' .. errinput .. '})'))
+        eq(errmsg, pcall_err(command, 'echo ' .. func .. '([' .. errinput .. '])'))
+        eq(errmsg, pcall_err(command, 'echo ' .. func .. '({1:' .. errinput .. '})'))
       end
     end)
     it('works with arrays/dictionaries with zero items', function()
@@ -42,9 +41,8 @@ for _, func in ipairs({'min', 'max'}) do
     it('errors out for invalid types', function()
       for _, errinput in ipairs({'1', 'v:true', 'v:false', 'v:null',
                                  'function("tr")', '""'}) do
-        eq(('\nE712: Argument of %s() must be a List or Dictionary\n0'):format(
-            func),
-           redir_exec('echo ' .. func .. '(' .. errinput .. ')'))
+        eq(('Vim(echo):E712: Argument of %s() must be a List or Dictionary'):format(func),
+           pcall_err(command, 'echo ' .. func .. '(' .. errinput .. ')'))
       end
     end)
   end)