Before: call ale#test#SetDirectory('/testplugin/test/fixers') After: call ale#test#RestoreDirectory() Execute(Long lines with basic function calls should be broken up correctly): AssertEqual \ [ \ 'def foo():', \ ' some_variable = this_is_a_longer_function(', \ 'first_argument,', \ ' second_argument,', \ ' third_with_function_call(', \ 'foo,', \ ' bar,', \ '))', \ ], \ ale#fixers#generic_python#BreakUpLongLines(bufnr(''), [ \ 'def foo():', \ ' some_variable = this_is_a_longer_function(first_argument, second_argument, third_with_function_call(foo, bar))', \ ]) Execute(Longer lines should be permitted if a configuration file allows it): call ale#test#SetFilename('long-line-project/foo/bar.py') AssertEqual \ [ \ 'x = this_line_is_between_79_and_90_characters(first, second, third, fourth, fifth)', \ 'y = this_line_is_longer_than_90_characters(', \ 'much_longer_word,', \ ' another_longer_word,', \ ' a_third_long_word,', \ ')' \ ], \ ale#fixers#generic_python#BreakUpLongLines(bufnr(''), [ \ 'x = this_line_is_between_79_and_90_characters(first, second, third, fourth, fifth)', \ 'y = this_line_is_longer_than_90_characters(much_longer_word, another_longer_word, a_third_long_word)', \ ])