Before:
  Save g:ale_fixers
  Save &shell
  Save g:ale_enabled
  Save g:ale_fix_on_save
  Save g:ale_lint_on_save
  Save g:ale_echo_cursor

  silent! cd /testplugin/test/fix

  let g:ale_enabled = 0
  let g:ale_echo_cursor = 0
  let g:ale_run_synchronously = 1
  let g:ale_set_lists_synchronously = 1
  let g:ale_fix_buffer_data = {}
  let g:ale_fixers = {
  \ 'testft': [],
  \}

  let g:pre_success = 0
  let g:post_success = 0
  augroup VaderTest
    autocmd!
    autocmd User ALEFixPre let g:pre_success = 1
    autocmd User ALEFixPost let g:post_success = 1
  augroup end

  if !has('win32')
    let &shell = '/bin/bash'
  endif

  call ale#test#SetDirectory('/testplugin/test')
  call ale#test#SetFilename('test.txt')

  function AddCarets(buffer, lines) abort
    " map() is applied to the original lines here.
    " This way, we can ensure that defensive copies are made.
    return map(a:lines, '''^'' . v:val')
  endfunction

  function AddDollars(buffer, lines) abort
    return map(a:lines, '''$'' . v:val')
  endfunction

  function DoNothing(buffer, lines) abort
    return 0
  endfunction

  function CatLine(buffer, lines) abort
    return {'command': 'cat - <(echo d)'}
  endfunction

  function CatLineOneArg(buffer) abort
    return {'command': 'cat - <(echo d)'}
  endfunction

  function ReplaceWithTempFile(buffer, lines) abort
    return {'command': 'echo x > %t', 'read_temporary_file': 1}
  endfunction

  function RemoveLastLine(buffer, lines) abort
    return ['a', 'b']
  endfunction

  function RemoveLastLineOneArg(buffer) abort
    return ['a', 'b']
  endfunction

  function! TestCallback(buffer, output)
    return [{'lnum': 1, 'col': 1, 'text': 'xxx'}]
  endfunction

  function! FirstChainCallback(buffer)
    return {'command': 'echo echoline', 'chain_with': 'SecondChainCallback'}
  endfunction

  function! FirstChainCallbackSkipped(buffer)
    let l:ChainWith = 'SecondChainCallback'

    " Test with lambdas where support is available.
    if has('lambda')
      let l:ChainWith = {buffer, output -> SecondChainCallback(buffer, output)}
    endif

    return {'command': '', 'chain_with': l:ChainWith}
  endfunction

  function! FirstChainCallbackSecondSkipped(buffer)
    return {'command': 'echo skipit', 'chain_with': 'SecondChainCallback'}
  endfunction

  function! SecondChainCallback(buffer, output)
    let l:previous_line = empty(a:output)
    \ ? 'emptydefault'
    \ : join(split(a:output[0]))

    if l:previous_line is# 'skipit'
      return {'command': '', 'chain_with': 'ThirdChainCallback'}
    endif

    return {
    \ 'command': 'echo ' . l:previous_line,
    \ 'chain_with': 'ThirdChainCallback',
    \}
  endfunction

  function! ThirdChainCallback(buffer, output, input)
    let l:previous_line = empty(a:output)
    \ ? 'thirddefault'
    \ : join(split(a:output[0]))

    return a:input + [l:previous_line]
  endfunction

  function! ChainWhereLastIsSkipped(buffer)
    return {'command': 'echo echoline', 'chain_with': 'ChainEndSkipped'}
  endfunction

  function! ChainEndSkipped(buffer, output)
    return {'command': ''}
  endfunction

  " echo will output a single blank line, and we should ingore it.
  function! IgnoredEmptyOutput(buffer, output)
    return {'command': has('win32') ? 'echo(' : 'echo'}
  endfunction

  function! EchoLineNoPipe(buffer, output)
    return {'command': 'echo new line', 'read_buffer': 0}
  endfunction

  function! SetUpLinters()
    call ale#linter#Define('testft', {
    \ 'name': 'testlinter',
    \ 'callback': 'TestCallback',
    \ 'executable': 'true',
    \ 'command': 'true',
    \})
  endfunction

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

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

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

  function! FixWithJSONPostProcessing(buffer) abort
    let l:ProcessWith = 'JSONPostProcessor'

    " Test with lambdas where support is available.
    if has('lambda')
      let l:ProcessWith = {buffer, output -> JSONPostProcessor(buffer, output)}
    endif

    " Escaping needs to be handled specially for CMD on Windows.
    let l:json_string = has('win32')
    \ ? '{"output":["x","y","z"]}'
    \ : ale#Escape('{"output": ["x", "y", "z"]}')

    return {
    \ 'command': 'echo ' . l:json_string,
    \ 'read_buffer': 0,
    \ 'process_with': l:ProcessWith,
    \}
  endfunction

  function! JSONPostProcessor(buffer, output) abort
    return json_decode(a:output[0]).output
  endfunction

After:
  Restore
  unlet! g:ale_run_synchronously
  unlet! g:ale_set_lists_synchronously
  unlet! g:ale_emulate_job_failure
  unlet! b:ale_fixers
  unlet! b:ale_fix_on_save
  augroup! VaderTest
  delfunction AddCarets
  delfunction AddDollars
  delfunction DoNothing
  delfunction CatLine
  delfunction CatLineOneArg
  delfunction ReplaceWithTempFile
  delfunction RemoveLastLine
  delfunction RemoveLastLineOneArg
  delfunction TestCallback
  delfunction FirstChainCallback
  delfunction FirstChainCallbackSkipped
  delfunction FirstChainCallbackSecondSkipped
  delfunction SecondChainCallback
  delfunction ThirdChainCallback
  delfunction ChainWhereLastIsSkipped
  delfunction ChainEndSkipped
  delfunction SetUpLinters
  delfunction GetLastMessage
  delfunction IgnoredEmptyOutput
  delfunction EchoLineNoPipe
  delfunction FixWithJSONPostProcessing
  delfunction JSONPostProcessor

  call ale#test#RestoreDirectory()

  call ale#fix#registry#ResetToDefaults()
  call ale#linter#Reset()

  setlocal buftype=nofile

  if filereadable('fix_test_file')
    call delete('fix_test_file')
  endif

  call setloclist(0, [])

  let g:ale_fix_buffer_data = {}

  " Clear the messages between tests.
  echomsg ''

Given testft (A file with three lines):
  a
  b
  c

Execute(ALEFix should complain when there are no functions to call):
  ALEFix
  AssertEqual 'No fixers have been defined. Try :ALEFixSuggest', GetLastMessage()

Execute(ALEFix should apply simple functions):
  let g:ale_fixers.testft = ['AddCarets']
  ALEFix

Expect(The first function should be used):
  ^a
  ^b
  ^c

Execute(ALEFix should apply simple functions in a chain):
  let g:ale_fixers.testft = ['AddCarets', 'AddDollars']
  ALEFix

Expect(Both functions should be used):
  $^a
  $^b
  $^c

Execute(ALEFix should allow 0 to be returned to skip functions):
  let g:ale_fixers.testft = ['DoNothing', 'AddDollars']
  ALEFix

Expect(Only the second function should be applied):
  $a
  $b
  $c

Execute(ALEFix should allow commands to be run):
  if has('win32')
    " Just skip this test on Windows, we can't run it.
    call setline(1, ['a', 'b', 'c', 'd'])
  else
    let g:ale_fixers.testft = ['CatLine']
    ALEFix
  endif

Expect(An extra line should be added):
  a
  b
  c
  d

Execute(ALEFix should use fixers passed in commandline when provided):
  let g:ale_fixers.testft = ['RemoveLastLine']
  ALEFix AddCarets AddDollars

Expect(Only fixers passed via command line should be run):
  $^a
  $^b
  $^c

Execute(ALEFix should allow temporary files to be read):
  if has('win32')
    " Just skip this test on Windows, we can't run it.
    call setline(1, ['x'])
    2,3d
  else
    let g:ale_fixers.testft = ['ReplaceWithTempFile']
    ALEFix
  endif

Expect(The line we wrote to the temporary file should be used here):
  x

Execute(ALEFix should allow jobs and simple functions to be combined):
  if has('win32')
    " Just skip this test on Windows, we can't run it.
    call setline(1, ['$x'])
    2,3d
  else
    let g:ale_fixers.testft = ['ReplaceWithTempFile', 'AddDollars']
    ALEFix
  endif

Expect(The lines from the temporary file should be modified):
  $x

Execute(ALEFix should send lines modified by functions to jobs):
  if has('win32')
    " Just skip this test on Windows, we can't run it.
    call setline(1, ['$a', '$b', '$c', 'd'])
  else
    let g:ale_fixers.testft = ['AddDollars', 'CatLine']
    ALEFix
  endif

Expect(The lines should first be modified by the function, then the job):
  $a
  $b
  $c
  d

Execute(ALEFix should skip commands when jobs fail to run):
  let g:ale_emulate_job_failure = 1
  let g:ale_fixers.testft = ['CatLine', 'AddDollars']
  ALEFix

Expect(Only the second function should be applied):
  $a
  $b
  $c

Execute(ALEFix should handle strings for selecting a single function):
  let g:ale_fixers.testft = 'AddCarets'
  ALEFix

Expect(The first function should be used):
  ^a
  ^b
  ^c

Execute(ALEFix should use functions from the registry):
  call ale#fix#registry#Add('add_carets', 'AddCarets', [], 'Add some carets')
  let g:ale_fixers.testft = ['add_carets']
  ALEFix

Expect(The registry function should be used):
  ^a
  ^b
  ^c

Execute(ALEFix should be able to remove the last line for files):
  let g:ale_fixers.testft = ['RemoveLastLine']
  ALEFix

Expect(There should be only two lines):
  a
  b

Execute(ALEFix should accept funcrefs):
  let g:ale_fixers.testft = [function('RemoveLastLine')]
  ALEFix

Expect(There should be only two lines):
  a
  b

Execute(ALEFix should accept lambdas):
  if has('nvim')
    " NeoVim 0.1.7 can't interpret lambdas correctly, so just set the lines
    " to make the test pass.
    call setline(1, ['a', 'b', 'c', 'd'])
  else
    let g:ale_fixers.testft = [{buffer, lines -> lines + ['d']}]
    ALEFix
  endif

Expect(There should be an extra line):
  a
  b
  c
  d

Execute(ALEFix should user buffer-local fixer settings):
  let g:ale_fixers.testft = ['AddCarets', 'AddDollars']
  let b:ale_fixers = {'testft': ['RemoveLastLine']}
  ALEFix

Expect(There should be only two lines):
  a
  b

Execute(ALEFix should allow Lists to be used for buffer-local fixer settings):
  let g:ale_fixers.testft = ['AddCarets', 'AddDollars']
  let b:ale_fixers = ['RemoveLastLine']
  ALEFix

Expect(There should be only two lines):
  a
  b

Given testft (A file with three lines):
  a
  b
  c

Execute(ALEFix should save files on the save event):
  let g:ale_fix_on_save = 1
  let g:ale_lint_on_save = 1
  let g:ale_enabled = 1

  noautocmd silent file fix_test_file
  call writefile(getline(1, '$'), 'fix_test_file')

  let g:ale_fixers.testft = ['AddDollars']

  " We have to set the buftype to empty so the file will be written.
  setlocal buftype=

  call SetUpLinters()
  call ale#events#SaveEvent(bufnr(''))

  " We should save the file.
  AssertEqual ['$a', '$b', '$c'], readfile('fix_test_file')
  Assert !&modified, 'The was marked as ''modified'''

  if !has('win32')
    " We should have run the linter.
    AssertEqual [{
    \   'bufnr': bufnr('%'),
    \   'lnum': 1,
    \   'vcol': 0,
    \   'col': 1,
    \   'text': 'xxx',
    \   'type': 'E',
    \   'nr': -1,
    \   'pattern': '',
    \   'valid': 1,
    \}], getloclist(0)
  endif

Expect(The buffer should be modified):
  $a
  $b
  $c

Given testft (A file with three lines):
  a
  b
  c

Execute(ALEFix should still lint with no linters to be applied):
  let g:ale_fix_on_save = 1
  let g:ale_lint_on_save = 1
  let g:ale_enabled = 1

  noautocmd silent file fix_test_file

  let g:ale_fixers.testft = []

  call SetUpLinters()
  call ale#events#SaveEvent(bufnr(''))

  Assert !filereadable('fix_test_file'), 'The file should not have been saved'

  if !has('win32')
    " We have run the linter.
    AssertEqual [{
    \   'bufnr': bufnr('%'),
    \   'lnum': 1,
    \   'vcol': 0,
    \   'col': 1,
    \   'text': 'xxx',
    \   'type': 'E',
    \   'nr': -1,
    \   'pattern': '',
    \   'valid': 1,
    \}], getloclist(0)
  endif

Expect(The buffer should be the same):
  a
  b
  c

Execute(ALEFix should still lint when nothing was fixed on save):
  let g:ale_fix_on_save = 1
  let g:ale_lint_on_save = 1
  let g:ale_enabled = 1

  noautocmd silent file fix_test_file

  let g:ale_fixers.testft = ['DoNothing']

  call SetUpLinters()
  call ale#events#SaveEvent(bufnr(''))

  Assert !filereadable('fix_test_file'), 'The file should not have been saved'

  if !has('win32')
    " We should have run the linter.
    AssertEqual [{
    \   'bufnr': bufnr('%'),
    \   'lnum': 1,
    \   'vcol': 0,
    \   'col': 1,
    \   'text': 'xxx',
    \   'type': 'E',
    \   'nr': -1,
    \   'pattern': '',
    \   'valid': 1,
    \}], getloclist(0)
  endif

Expect(The buffer should be the same):
  a
  b
  c

Given testft (A file with three lines):
  a
  b
  c

Execute(ale#fix#InitBufferData() should set up the correct data):
  noautocmd silent file fix_test_file

  call ale#fix#InitBufferData(bufnr(''), 'save_file')

  AssertEqual {
  \ bufnr(''): {
  \   'temporary_directory_list': [],
  \   'vars': b:,
  \   'filename': ale#path#Simplify(getcwd() . '/fix_test_file'),
  \   'done': 0,
  \   'lines_before': ['a', 'b', 'c'],
  \   'should_save': 1,
  \ },
  \}, g:ale_fix_buffer_data

Execute(ALEFix simple functions should be able to accept one argument, the buffer):
  let g:ale_fixers.testft = ['RemoveLastLineOneArg']
  ALEFix

Expect(There should be only two lines):
  a
  b

Execute(b:ale_fix_on_save = 1 should override g:ale_fix_on_save = 0):
  let g:ale_fix_on_save = 0
  let b:ale_fix_on_save = 1

  let g:ale_fixers.testft = ['RemoveLastLineOneArg']
  call ale#events#SaveEvent(bufnr(''))

Expect(There should be only two lines):
  a
  b

Execute(b:ale_fix_on_save = 0 should override g:ale_fix_on_save = 1):
  let g:ale_fix_on_save = 1
  let b:ale_fix_on_save = 0

  let g:ale_fixers.testft = ['RemoveLastLineOneArg']
  call ale#events#SaveEvent(bufnr(''))

Expect(The lines should be the same):
  a
  b
  c

Execute(ALEFix functions returning jobs should be able to accept one argument):
  if has('win32')
    " Just skip this test on Windows, we can't run it.
    call setline(1, ['a', 'b', 'c', 'd'])
  else
    let g:ale_fixers.testft = ['CatLine']
    ALEFix
  endif

Expect(An extra line should be added):
  a
  b
  c
  d

Execute(ALE should print a message telling you something isn't a valid fixer when you type some nonsense):
  let g:ale_fixers.testft = ['CatLine', 'invalidname']
  ALEFix

  AssertEqual 'There is no fixer named `invalidname`. Check :ALEFixSuggest', GetLastMessage()

Execute(ALE should complain about invalid fixers with minuses in the name):
  let g:ale_fixers.testft = ['foo-bar']
  ALEFix

  AssertEqual 'There is no fixer named `foo-bar`. Check :ALEFixSuggest', GetLastMessage()

Execute(ALE should tolerate valid fixers with minuses in the name):
  let g:ale_fixers.testft = ['prettier-standard']
  ALEFix

Execute(Test fixing with chained callbacks):
  let g:ale_fixers.testft = ['FirstChainCallback']
  ALEFix

  " The buffer shouldn't be piped in for earlier commands in the chain.
  AssertEqual
  \ [
  \   string(ale#job#PrepareCommand(bufnr(''), 'echo echoline')),
  \   string(ale#job#PrepareCommand(bufnr(''), 'echo echoline')),
  \ ],
  \ map(ale#history#Get(bufnr(''))[-2:-1], 'string(v:val.command)')

Expect(The echoed line should be added):
  a
  b
  c
  echoline

Execute(Test fixing with chained callback where the first command is skipped):
  let g:ale_fixers.testft = ['FirstChainCallbackSkipped']
  ALEFix

Expect(The default line should be added):
  a
  b
  c
  emptydefault

Execute(Test fixing with chained callback where the second command is skipped):
  let g:ale_fixers.testft = ['FirstChainCallbackSecondSkipped']
  ALEFix

Expect(The default line should be added):
  a
  b
  c
  thirddefault

Execute(Test fixing with chained callback where the final callback is skipped):
  let g:ale_fixers.testft = ['ChainWhereLastIsSkipped']
  ALEFix

Expect(The lines should be the same):
  a
  b
  c

Execute(Empty output should be ignored):
  let g:ale_fixers.testft = ['IgnoredEmptyOutput']
  ALEFix

Expect(The lines should be the same):
  a
  b
  c

Execute(A temporary file shouldn't be piped into the command when disabled):
  let g:ale_fixers.testft = ['EchoLineNoPipe']
  ALEFix

  AssertEqual
  \ string(ale#job#PrepareCommand(bufnr(''), 'echo new line')),
  \ string(ale#history#Get(bufnr(''))[-1].command)

  " Remove trailing whitespace for Windows.
  if has('win32')
    %s/[[:space:]]*$//g
  endif

Expect(The new line should be used):
  new line

Execute(Post-processing should work):
  let g:ale_fixers.testft = ['FixWithJSONPostProcessing']
  ALEFix

Expect(The lines in the JSON should be used):
  x
  y
  z

Execute(ALEFix should apply autocmds):
  let g:ale_fixers.testft = ['AddCarets']
  ALEFix
  AssertEqual g:pre_success, 1
  AssertEqual g:post_success, 1