Before:
  runtime ale_linters/python/flake8.vim
  silent! execute 'cd /testplugin/test/command_callback'
  let g:dir = getcwd()

After:
  silent execute 'cd ' . fnameescape(g:dir)
  " Set the file to something else,
  " or we'll cause issues when running other tests
  silent file 'dummy.py'
  unlet! g:dir

  call ale#linter#Reset()
  let g:ale_python_flake8_executable = 'flake8'
  let g:ale_python_flake8_options = ''
  let g:ale_python_flake8_use_global = 0

  call ale_linters#python#flake8#ClearVersionCache()

Execute(The flake8 callbacks should return the correct default values):
  AssertEqual
  \ 'flake8',
  \ ale_linters#python#flake8#GetExecutable(bufnr(''))
  AssertEqual
  \ 'flake8 --version',
  \ ale_linters#python#flake8#VersionCheck(bufnr(''))
  AssertEqual
  \ 'flake8 --stdin-display-name %s -',
  \ ale_linters#python#flake8#GetCommand(bufnr(''), ['3.0.0'])
  " Try with older versions.
  call ale_linters#python#flake8#ClearVersionCache()
  AssertEqual
  \ 'flake8 -',
  \ ale_linters#python#flake8#GetCommand(bufnr(''), ['2.9.9'])

Execute(The flake8 command callback should let you set options):
  let g:ale_python_flake8_options = '--some-option'

  AssertEqual
  \ 'flake8 --some-option --stdin-display-name %s -',
  \ ale_linters#python#flake8#GetCommand(bufnr(''), ['3.0.4'])
  call ale_linters#python#flake8#ClearVersionCache()
  AssertEqual
  \ 'flake8 --some-option -',
  \ ale_linters#python#flake8#GetCommand(bufnr(''), ['2.9.9'])

Execute(You should be able to set a custom executable and it should be escaped):
  let g:ale_python_flake8_executable = 'executable with spaces'

  AssertEqual
  \ 'executable with spaces',
  \ ale_linters#python#flake8#GetExecutable(bufnr(''))
  AssertEqual
  \ 'executable\ with\ spaces --version',
  \ ale_linters#python#flake8#VersionCheck(bufnr(''))
  AssertEqual
  \ 'executable\ with\ spaces --stdin-display-name %s -',
  \ ale_linters#python#flake8#GetCommand(bufnr(''), ['3.0.0'])

Execute(The flake8 callbacks should detect virtualenv directories):
  silent execute 'file ' . fnameescape(g:dir . '/python_paths/with_virtualenv/subdir/foo/bar.py')

  AssertEqual
  \ g:dir . '/python_paths/with_virtualenv/env/bin/flake8',
  \ ale_linters#python#flake8#GetExecutable(bufnr(''))
  AssertEqual
  \ g:dir . '/python_paths/with_virtualenv/env/bin/flake8 --version',
  \ ale_linters#python#flake8#VersionCheck(bufnr(''))
  AssertEqual
  \   g:dir . '/python_paths/with_virtualenv/env/bin/flake8'
  \   . ' --stdin-display-name %s -',
  \ ale_linters#python#flake8#GetCommand(bufnr(''), ['3.0.0'])