[SHIPA-2139] enforce unit test coverage

[stinkyfingers]

Description

Fixes # 2139

Relies on https://github.com/theketchio/unit-test-coverage, which I made public. unit-test-coverage may be used by our private shipa repos, but I figured it should be public as it is used by Ketch. This PR adds CI steps that run unit-test-covreage using ci/limits.json. In the event test coverage drops below the current level specified in limits.json, you'll get a failure and see output like this:

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Chore (documentation addition or typo, file relocation)

Testing

• New tests were added with this PR that prove my fix is effective or that my feature works (describe below this bullet)
• This change requires no testing (i.e. documentation update)

Documentation

• All added public packages, funcs, and types have been documented with doc comments
• I have commented my code, particularly in hard-to-understand areas

Final Checklist:

• I followed standard GitHub flow guidelines
• I have performed a self-review of my own code
• My changes generate no new warnings

[DavisFrench]

This looks good to me. I am a bit curious though, is this kind of constraint usually defined within the codebase as opposed to the ci/cd pipeline?

[stinkyfingers]

@DavisFrench I have the same question. Maybe it would be more idiomatic to just sed package coverages and compare to some file maintained in the .github directory?

[stinkyfingers]

@DavisFrench Forget everything I said. I moved the unit-test-coverage script to a separate repo. This PR is just the CI steps now.

[aleksej-paschenko]

looks awesome!