Reporting bugs effectively

So you found a problem in CodeMirror. By all means, report it! Bug reports from users are the main drive behind improvements to CodeMirror. But first, please read over these points:

  1. CodeMirror is maintained by volunteers. They don't owe you anything, so be polite. Reports with an indignant or belligerent tone tend to be moved to the bottom of the pile.
  2. Include information about the browser in which the problem occurred. Even if you tested several browsers, and the problem occurred in all of them, mention this fact in the bug report. Also include browser version numbers and the operating system that you're on.
  3. Mention which release of CodeMirror you're using. Preferably, try also with the current development snapshot, to ensure the problem has not already been fixed.
  4. Mention very precisely what went wrong. "X is broken" is not a good bug report. What did you expect to happen? What happened instead? Describe the exact steps a maintainer has to take to make the problem occur. We can not fix something that we can not observe.
  5. If the problem can not be reproduced in any of the demos included in the CodeMirror distribution, please provide an HTML document that demonstrates the problem. The best way to do this is to go to, enter it there, press save, and include the resulting link in your bug report.