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'])

" Some users currently run flake8 this way, so we should support it.
Execute(Using `python -m flake8` should be supported for running flake8):
  silent execute 'file ' . fnameescape(g:dir . '/python_paths/with_virtualenv/subdir/foo/bar.py')

  let g:ale_python_flake8_executable = 'python'
  let g:ale_python_flake8_options = '-m flake8 --some-option'

  AssertEqual
  \ 'python',
  \ ale_linters#python#flake8#GetExecutable(bufnr(''))
  AssertEqual
  \ '''python'' -m flake8 --version',
  \ ale_linters#python#flake8#VersionCheck(bufnr(''))
  AssertEqual
  \ '''python'' -m flake8 --some-option -',
  \ ale_linters#python#flake8#GetCommand(bufnr(''), ['2.9.9'])

  call ale_linters#python#flake8#ClearVersionCache()

  " Leading spaces shouldn't matter
  let g:ale_python_flake8_options = '  -m flake8 --some-option'

  AssertEqual
  \ 'python',
  \ ale_linters#python#flake8#GetExecutable(bufnr(''))
  AssertEqual
  \ '''python'' -m flake8 --version',
  \ ale_linters#python#flake8#VersionCheck(bufnr(''))
  AssertEqual
  \ '''python''   -m flake8 --some-option -',
  \ ale_linters#python#flake8#GetCommand(bufnr(''), ['2.9.9'])