Before:
  Save g:ale_rust_rustfmt_executable
  Save g:ale_rust_rustfmt_options

  " Use an invalid global executable, so we don't match it.
  let g:ale_rust_rustfmt_executable = 'xxxinvalid'
  let g:ale_rust_rustfmt_options = ''

  call ale#test#SetDirectory('/testplugin/test/fixers')

After:
  Restore

  call ale#test#RestoreDirectory()

Execute(The rustfmt callback should return the correct default values):
  call ale#test#SetFilename('../rust_files/testfile.rs')

  AssertEqual
  \ {
  \   'read_temporary_file': 1,
  \   'command': ale#Escape('xxxinvalid')
  \     . ' %t',
  \ },
  \ ale#fixers#rustfmt#Fix(bufnr(''))

Execute(The rustfmt callback should include custom rustfmt options):
  let g:ale_rust_rustfmt_options = "--skip-children"
  call ale#test#SetFilename('../rust_files/testfile.rs')

  AssertEqual
  \ {
  \   'read_temporary_file': 1,
  \   'command': ale#Escape('xxxinvalid')
  \     . ' ' . g:ale_rust_rustfmt_options
  \     . ' %t',
  \ },
  \ ale#fixers#rustfmt#Fix(bufnr(''))