Before: call ale#assert#SetUpLinterTest('eruby', 'erb') After: call ale#assert#TearDownLinterTest() Execute(Executable should not contain any filter code by default): call ale#test#SetFilename('../test-files/ruby/not_a_rails_app/file.rb') AssertLinter 'erb', 'erb -P -T - -x %t | ruby -c' Execute(Executable should filter invalid eRuby when inside a Rails project): call ale#test#SetFilename('../test-files/ruby/valid_rails_app/app/views/my_great_view.html.erb') AssertLinter 'erb', \ 'ruby -r erb -e ' . ale#Escape('puts ERB.new($stdin.read.gsub(%{<%=},%{<%}), trim_mode: %{-}).src') . '< %t | ruby -c'