I want to detect errors in my HTML during development.
This should be detected.
- open source
- self-hosting: the library should not need a service like https://validator.w3.org/
- Unknown attributes should get detected (example "hrf" instead of "href").
- extensible: There should be a way to configure it, so that non-standard attributes (example like https://htmx.org/) are ignored.
- Command line interface or library which is usable via python.
- Should work for html5
Background: I did a refactoring in my code and no automated test complained. But there were bugs (see above example). I would like to automate html checking to be sure this does not happen again.
BTW: It is enough to detect the error. No automatic fixing should be attempted.