Before: call ale#assert#SetUpFixerTest('zig', 'zigfmt') After: call ale#assert#TearDownFixerTest() Execute(The zig callback should return the correct default values): AssertFixer { \ 'command': ale#Escape('zig') . ' fmt %t', \ 'read_temporary_file': 1, \} Execute(The zig callback should allow custom zig executables): let g:ale_zig_zigfmt_executable = 'foo/bar' AssertFixer { \ 'command': ale#Escape('foo/bar') . ' fmt %t', \ 'read_temporary_file': 1, \}