Stop using istanbul-api

[coreyfarrell]

Summary

I plan to deprecate istanbul-api after the current semver-major. Switching jest's own test coverage reporting was the easier first step to making this switch so I've done this first.

Test plan

I first ran yarn && yarn test-ci on the existing master branch. I encountered errors with hg tests so I manually ran node scripts/mapCoverage.js after. I then made a backup of the coverage folder, ran rm -fr coverage/lcov*, then ran node scripts/mapCoverage.js with my updates. I verified that timestamps in the HTML reports were the only thing to change before/after my change.

[facebook-github-bot]

Thank you for your pull request and welcome to our community. We require contributors to sign our Contributor License Agreement, and we don't seem to have you on file. In order for us to review and merge your code, please sign up at https://code.facebook.com/cla. If you are contributing on behalf of someone else (eg your employer), the individual CLA may not be sufficient and your employer may need the corporate CLA signed.

If you have received this in error or have any questions, please contact us at cla@fb.com. Thanks!

[SimenB]

Thanks @coreyfarrell!

This just updates what Jest uses during its own test runs. Could you also update the reporter jest uses in the normal case?

https://github.com/facebook/jest/blob/06842633c42580607874430f47b858359967d4ee/packages/jest-reporters/src/coverage_reporter.ts#L15

(and delete the vendored .d.ts file we have for istanbul-api 🙂)

[facebook-github-bot]

Thank you for signing our Contributor License Agreement. We can now accept your code for this (and any) Facebook open source project. Thanks!

[coreyfarrell]

@SimenB yes that'll be next. Just wanted to start with something that was easier to test. I'll be AFK for a couple hours I'll try to work on the production reporter later today.

[SimenB]

Perfect! Our own coverage run is ci/circleci: test-node-10, so if that's green then this first one worked great 🙂 When changing the jest reporter, every test run will test it since we have integration tests

[codecov-io]

Codecov Report

Merging #8294 into master will increase coverage by 0.02%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #8294      +/-   ##
==========================================
+ Coverage   62.22%   62.24%   +0.02%     
==========================================
  Files         266      266              
  Lines       10720    10719       -1     
  Branches     2609     2607       -2     
==========================================
+ Hits         6670     6672       +2     
+ Misses       3463     3462       -1     
+ Partials      587      585       -2

Impacted Files	Coverage Δ
packages/jest-reporters/src/coverage_reporter.ts	61.53% <100%> (+1.99%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 65b48a7...4411299. Read the comment docs.

[SimenB]

CI passed! 🎉 I'll figure out what parts to keep from the deleted test and merge this. Thanks @coreyfarrell!

[github-actions]

This pull request has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.
Please note this issue tracker is not a help forum. We recommend using StackOverflow or our discord channel for questions.