After:
  call ale#linter#Reset()

Execute(The luacheck handler should parse lines correctly):
  runtime ale_linters/lua/luacheck.vim

  AssertEqual
  \ [
  \   {
  \     'lnum': 1,
  \     'col': 8,
  \     'text': 'W612: line contains trailing whitespace',
  \     'type': 'W',
  \   },
  \   {
  \     'lnum': 3,
  \     'col': 5,
  \     'text': 'W213: unused loop variable ''k''',
  \     'type': 'W',
  \   },
  \   {
  \     'lnum': 3,
  \     'col': 19,
  \     'text': 'W113: accessing undefined variable ''x''',
  \     'type': 'W',
  \   },
  \ ],
  \ ale_linters#lua#luacheck#Handle(347, [
  \   '    /file/path/here.lua:1:8: (W612) line contains trailing whitespace',
  \   '    /file/path/here.lua:3:5: (W213) unused loop variable ''k''',
  \   '    /file/path/here.lua:3:19: (W113) accessing undefined variable ''x''',
  \ ])