feat(testing): add codecov to generate test coverage reports

[jsjoeio]

This PR adds support to generate test coverage reports on PRs using @codecov

Changes

• add CODECOV_TOKEN secret to project
• add clover to coverageReporters for unit tests (see jest key on package.json)
• add codecov as dev dependency
• add coverage script to package.json
• add ci step to run yarn coverage

Screenshots

todo

Checklist

• dependencies added

Fixes #3151

[jawnsy]

TIL about clover! very cool. from this config it looks like collecting JS test coverage metrics isn't too difficult! definitely something we'd love to get your guidance with on the product side, I think, at some point :)

[jsjoeio]

Right?! I think it should be pretty easy. I believe I just need to install codecov then run it in CI and it should upload the results for us.

Would be more than happy to help on the product side :D

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (main@72ca12c). Click here to learn what that means.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #3194   +/-   ##
=======================================
  Coverage        ?   46.77%           
=======================================
  Files           ?       23           
  Lines           ?     1193           
  Branches        ?      237           
=======================================
  Hits            ?      558           
  Misses          ?      451           
  Partials        ?      184           

---

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 72ca12c...bb0414e. Read the comment docs.

[jsjoeio]

❗ No coverage uploaded for pull request base (main@72ca12c). Click here to learn what that means.
The diff coverage is n/a.

I believe this is because it's looking for code coverage on the main branch which we don't have since this is the first time we're adding it 😂

Source