[TxMt] Regression tests for grammars?

[Stefan Daschek]

 From my - admittedly somewhat limited - experience with bundle grammars 
I got the feeling that it’s often very hard to improve or fix a grammar 
without accidentally breaking some other parts of it.

Has anyone already experimented with regression tests for bundle grammars?

I think to make this possible it would be necessary to somehow access 
the “scope structure” of a parsed file, maybe yielding a data structure 
like this:

   [
     { start: 0, end: 123, scope: "source.sass" },
     { start: 7, end: 12, scope: "string.quoted.double.sass" },
     …
   ]

Then a grammar could include both a “test source file” and its 
known-good “scope structure”. After changing the grammar one could 
(semi-)automatically regenerate the scope structure data and compare it 
to the original to (hopefully) catch any regressions.

Any thoughts?


Stefan