Before: call ale#assert#SetUpLinterTest('text', 'languagetool') After: call ale#assert#TearDownLinterTest() Execute(The default command should be correct): AssertLinter 'languagetool', ale#Escape('languagetool') \ . ' --autoDetect ' Execute(Should be able to set a custom executable): let g:ale_languagetool_executable = 'foobar' AssertLinter 'foobar' , ale#Escape('foobar') \ . ' --autoDetect '