Before: runtime ale_linters/java/checkstyle.vim After: call ale#linter#Reset() Execute(The checkstyle handler should parse lines correctly): AssertEqual \ [ \ { \ 'lnum': 101, \ 'col': 0, \ 'text': '''method def rcurly'' has incorrect indentation level 4, expected level should be 2.', \ 'code': 'Indentation', \ 'type': 'W', \ }, \ { \ 'lnum': 63, \ 'col': 3, \ 'text': 'Missing a Javadoc comment.', \ 'code': 'JavadocMethod', \ 'type': 'W', \ }, \ ], \ ale_linters#java#checkstyle#Handle(666, [ \ '[WARN] whatever:101: ''method def rcurly'' has incorrect indentation level 4, expected level should be 2. [Indentation]', \ '[WARN] whatever:63:3: Missing a Javadoc comment. [JavadocMethod]', \ ]) Execute(The checkstyle handler should parse lines from older checkstyle versions correctly): AssertEqual \ [ \ { \ 'lnum': 289, \ 'text': '''method def modifier'' have incorrect indentation level 4, expected level should be 2.', \ 'type': 'W', \ }, \ ], \ ale_linters#java#checkstyle#Handle(666, [ \ '/home/languitar/src/rsb-java/rsb-java/src/main/java/rsb/Listener.java:289: warning: ''method def modifier'' have incorrect indentation level 4, expected level should be 2.', \ ])