Jest: mapCoverage true by default

[eddyerburgh]

feature request - set mapCoverage to true by default

What is the current behavior?

mapCoverage is false by default

What is the expected behavior?

mapCoverage to be true by default

I maintain a jest-vue preprocessor.

A lot of users have problems with source maps. They don't realize you need to tell Jest to use source maps in the coverage reporter, so they think it's a problem with jest-vue.

Is there a reason it's false by default? I would think Jest would use source maps in coverage reporters by default

I'm happy to make a PR to change this

[eddyerburgh]

Could I get some feedback on this? I'm happy to create a PR if you want to make this change 😀. @thymikee @cpojer

[thymikee]

I'd rather ask @aaronabramov about that. Setting this to true by default could potentially make Jest slower for regular users.

[sparecycles]

I've had issues with mapCoverage fixing code coverage for vue, but it scrambles the code coverage for js files. I've tried modifying script_transformer.js to only apply mapCoverage to .vue files, and that worked great (actually, better for vue files which were included only because of collectCoverageFrom).

I'm using [email protected]

@eddyerburgh have you experienced anything similar? Currently I've worked around this by running jest twice with mapCoverage on for vue and off for js files but it would be nicer to be able to run jest once.

[eddyerburgh]

@sparecycles I've encountered this issue recently. I'll look into it

[KevinStong]

Any update on this? Not trying to be pushy :) just running into this and dealing with workarounds...

thanks!

Kevin

[SimenB]

See #5177, mapCoverage has been removed as of 22.4.0, its behaviour being the default