Before: Save g:ale_scala_scalastyle_options Save g:ale_scalastyle_config_loc unlet! g:ale_scala_scalastyle_options unlet! g:ale_scalastyle_config_loc runtime ale_linters/scala/scalastyle.vim After: Restore call ale#linter#Reset() Execute(Should return the correct default command): AssertEqual \ 'scalastyle %t', \ ale_linters#scala#scalastyle#GetCommand(bufnr('')) Execute(Should allow using a custom config file): let g:ale_scalastyle_config_loc = '/dooper/config.xml' AssertEqual \ 'scalastyle' \ . ' --config ' . ale#Escape('/dooper/config.xml') \ . ' %t', \ ale_linters#scala#scalastyle#GetCommand(bufnr('')) Execute(Should allow using custom options): let g:ale_scala_scalastyle_options = '--warnings false --quiet true' AssertEqual \ 'scalastyle' \ . ' --warnings false --quiet true' \ . ' %t', \ ale_linters#scala#scalastyle#GetCommand(bufnr(''))