[Question] does transformer only works for v8?

[stevez]

I saw monocart Istanbul report for playwright tests there are empty files are all zero lines, so I tried to use transformer() function, but it didn't help, so I wonder the transformer function only apply for v8 not Istanbul?

[cenfun]

Yes, the transformer only apply for V8 data. It's said, your report(v8 reports or istanbul reports) will not zero lines if base on V8 data (Array) otherwise will be 0 lines if base on Istanbul data (Object)