Before:
  call ale#assert#SetUpFixerTest('rust', 'rustfmt')

After:
  call ale#assert#TearDownFixerTest()

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

  AssertFixer {'command': ale#Escape('rustfmt')}

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

  AssertFixer {'command': ale#Escape('rustfmt') . ' ' . g:ale_rust_rustfmt_options}