Before: runtime ale_linters/chef/cookstyle.vim After: call ale#linter#Reset() Execute(Basic warnings should be handled): AssertEqual \ [ \ { \ 'lnum': 58, \ 'col': 24, \ 'code': 'Style/UnneededInterpolation', \ 'type': 'W', \ 'end_col': 40, \ 'text': 'Style/UnneededInterpolation: Prefer `to_s` over string interpolation.', \ } \ ], \ ale_linters#chef#cookstyle#Handle(bufnr(''), [ \ '{"metadata":{"rubocop_version":"0.62.0","ruby_engine":"ruby","ruby_version":"2.6.0","ruby_patchlevel":"0","ruby_platform":"x86_64-linux"},"files":[{"path":"recipes/default.rb","offenses":[{"severity":"convention","message":"Style/UnneededInterpolation: Prefer `to_s` over string interpolation.","cop_name":"Style/UnneededInterpolation","corrected":false,"location":{"start_line":58,"start_column":24,"last_line":58,"last_column":40,"length":17,"line":58,"column":24}}]}],"summary":{"offense_count":1,"target_file_count":1,"inspected_file_count":1}}' \ ])