Before: call ale#assert#SetUpFixerTest('nix', 'statix') After: call ale#assert#TearDownFixerTest() Execute(The callback should return the correct default values): AssertFixer { 'command': ale#Escape('statix') . ' fix --stdin' } Execute(The callback should include a custom runtime): let g:ale_nix_statix_fix_executable = 'foo/bar' AssertFixer { 'command': ale#Escape('foo/bar') . ' fix --stdin' } Execute(The callback should include custom options): let g:ale_nix_statix_fix_options = '--foobar' AssertFixer { 'command': ale#Escape('statix') . ' fix --stdin --foobar' }