Before: Save g:ale_haskell_ormolu_executable Save g:ale_haskell_ormolu_options After: Restore Execute(The ormolu callback should return the correct default values): AssertEqual \ { \ 'command': ale#Escape('ormolu') \ }, \ ale#fixers#ormolu#Fix(bufnr('')) Execute(The ormolu executable and options should be configurable): let g:ale_nix_nixpkgsfmt_executable = '/path/to/ormolu' let g:ale_nix_nixpkgsfmt_options = '-h' AssertEqual \ { \ 'command': ale#Escape('/path/to/ormolu') \ . ' -h', \ }, \ ale#fixers#nixpkgsfmt#Fix(bufnr(''))