I've asked :jkratzer offline how much coverage the Mozilla fuzzer team's work has of different shader source code.
Bug 1760648 Comment 1 Edit History
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According to :jkratzer:
> We have a very small corpus of working files that we use. Domino doesn't do any type of mutation on the shader source. That type of fuzzing I think is better handled via libfuzzer and oss-fuzz
So this is something we should undertake, and not assume that the Mozilla fuzzing team is going to cover it for us.