Before:
  Save g:ale_warn_about_trailing_whitespace

  let g:ale_warn_about_trailing_whitespace = 1

  runtime ale_linters/lua/luac.vim

After:
  Restore
  call ale#linter#Reset()

Execute(The luac handler should parse lines correctly):
  AssertEqual
  \ [
  \   {
  \     'lnum': 1,
  \     'text': 'line contains trailing whitespace',
  \     'type': 'E',
  \   },
  \   {
  \     'lnum': 3,
  \     'text': 'unexpected symbol near ''-''',
  \     'type': 'E',
  \   },
  \   {
  \     'lnum': 5,
  \     'text': '''='' expected near '')''',
  \     'type': 'E',
  \   },
  \ ],
  \ ale_linters#lua#luac#Handle(347, [
  \   'luac /file/path/here.lua:1: line contains trailing whitespace',
  \   'luac /file/path/here.lua:3: unexpected symbol near ''-''',
  \   'luac /file/path/here.lua:5: ''='' expected near '')''',
  \ ])