It seems like a major lapse in product innovation that Github has not come out with something like this. They don't even have something to help you when the indentation changes, they usually just show it as a giant add & remove. Their diff viewer can and should be smarter.
Github can't even recognize syntax, let alone provide semantic diffs! In fact, Github can't even tell that foo.cpp.in is different from foo.mk.in! Any foo.t is declared to be Perl, with no way to fix it…There are a decade-old tickets!
Tree-sitter optimizes for performance (to use in editors), not for correctness. In fact even TS' core developers advocate for not bothering too much with correctness of grammars[1]. I imagine this constraint would be a deal-breaker for GitHub or anyone else in their position.
