Before:
  let g:ale_buffer_info = {
  \ bufnr('%'): {
  \   'loclist': [
  \     {
  \       'lnum': 1,
  \       'col': 10,
  \       'bufnr': bufnr('%'),
  \       'vcol': 0,
  \       'linter_name': 'eslint',
  \       'nr': -1,
  \       'type': 'E',
  \       'text': 'Missing semicolon. (semi)',
  \       'detail': "Every statement should end with a semicolon\nsecond line"
  \     },
  \     {
  \       'lnum': 2,
  \       'col': 10,
  \       'bufnr': bufnr('%'),
  \       'vcol': 0,
  \       'linter_name': 'eslint',
  \       'nr': -1,
  \       'type': 'W',
  \       'text': 'Infix operators must be spaced. (space-infix-ops)'
  \     },
  \     {
  \       'lnum': 2,
  \       'col': 15,
  \       'bufnr': bufnr('%'),
  \       'vcol': 0,
  \       'linter_name': 'eslint',
  \       'nr': -1,
  \       'type': 'E',
  \       'text': 'Missing radix parameter (radix)'
  \     }
  \   ],
  \ },
  \}

  " Turn off other features, we only care about this one feature in this test.
  let g:ale_set_loclist = 0
  let g:ale_set_signs = 0
  let g:ale_set_highlights = 0

  function GetLastMessage()
    redir => l:output
      silent mess
    redir END

    let l:lines = split(l:output, "\n")

    return empty(l:lines) ? '' : l:lines[-1]
  endfunction

After:
  call cursor(1, 1)

  let g:ale_set_loclist = 1
  let g:ale_set_signs = 1
  let g:ale_set_highlights = 1

  let g:ale_buffer_info = {}

  unlet! g:output

  delfunction GetLastMessage

  " Clearing the messages breaks tests on NeoVim for some reason, but all
  " we need to do for these tests is just make it so the last message isn't
  " carried over between test cases.
  echomsg ''

Given javascript(A Javscript file with warnings/errors):
  var x = 3
  var x = 5*2 + parseInt("10");

Execute(Messages should be shown for the correct lines):
  call cursor(1, 1)
  call ale#cursor#EchoCursorWarning()

  AssertEqual 'Missing semicolon. (semi)', GetLastMessage()

Execute(Messages should be shown for earlier columns):
  call cursor(2, 1)
  call ale#cursor#EchoCursorWarning()

  AssertEqual 'Infix operators must be spaced. (space-infix-ops)', GetLastMessage()

Execute(Messages should be shown for later columns):
  call cursor(2, 16)
  call ale#cursor#EchoCursorWarning()

  AssertEqual 'Missing radix parameter (radix)', GetLastMessage()

Execute(The message at the cursor should be shown when linting ends):
  call cursor(1, 1)
  call ale#engine#SetResults(
  \ bufnr('%'),
  \ g:ale_buffer_info[bufnr('%')].loclist,
  \)

  AssertEqual 'Missing semicolon. (semi)', GetLastMessage()

Execute(The message at the cursor should be shown on InsertLeave):
  call cursor(2, 9)
  doautocmd InsertLeave

  AssertEqual 'Infix operators must be spaced. (space-infix-ops)', GetLastMessage()

Execute(ALEDetail should print 'detail' attributes):
  call cursor(1, 1)

  redir => g:output
    ALEDetail
  redir END

  AssertEqual "\nEvery statement should end with a semicolon\nsecond line", g:output

Execute(ALEDetail should print regular 'text' attributes):
  call cursor(2, 10)

  redir => g:output
    ALEDetail
  redir END

  AssertEqual "\nInfix operators must be spaced. (space-infix-ops)", g:output