[CI] mono_repo GitHub workflow setup with Coveralls

[dcharkes]

We currently have two workflows, one for each package.

• https://github.com/dart-lang/native/tree/main/.github/workflows

We should consider merging them into a single workflow using a matrix.

Pros:

• We don't repeat installing dependencies
• It might fix coveralls being confused about our repository
  • It combines coverage from jobs from a single workflow but not jobs from separate workflows. https://coveralls.io/builds/59018785 https://coveralls.io/builds/59018733

Cons:

• If we have packages that don't depend on each other, I don't know how to skip them.
  • (For now, I want to run the CI for native_assets_cli and c_compiler on PRs to both packages anyway. c_compiler immediately imports native_assets_cli, and the example in native_assets_cli imports c_compiler.)
• Coverage badge is per whole repo, not per package.
  • (Current setup makes the coverage for a single package and ignoring the other.)

Possibly there is a way to let coveralls combine the results from multiple jobs.
https://pub.dev/packages/mono_repo seems to indicate some support, but I'm not sure how to map that to the current workflows.
None of the listed mono_repo packages on the package documentation actually have coverage (badges).

(Slightly off-topic: Another thing to consider is to not split jobs at all, the packages need the same dependencies installed to run, installing those deps takes time as well.)

edit: trying to switch Coveralls to monorepo:

job list: https://coveralls.io/repos/400800/builds

edit 2: Having merged the last PR to main, I can see two builds for main:

• https://coveralls.io/builds/59102302
• https://coveralls.io/builds/59102307

Both of them report the correct coverage for the respective packages, but they are not aggregated correctly.

Based on https://github.com/marketplace/actions/coveralls-github-action, maybe it would work if we do a carryforward. (The next question then is if we can get badges for the individual packages.)

edit 3: trying to see what mono_repo generate would do as configuration: https://gist.github.com/dcharkes/338f175398ed0300151b5aa48ea3f878

Also a single file.

[dcharkes]

cc @kevmoo (as main contributor to package:mono_repo) Do we have a good story for package:mono_repo and properly working Coveralls reports? Should I be using mono_repo generate over manually making GitHub workflows? I'd love to learn more about how to set this up properly.

[kevmoo]

@dcharkes – I added coverage a while ago. It works!

# When using `test_with_coverage`, this setting configures the service that
# results are uploaded to.
# Note: you can configure both options, but this would be unusual.
# Note: you can configure this key with no values, to just generate the files
#   locally. This may be to enable other, custom processing.
coverage_service:
# https://coveralls.io/ - the default
- coveralls
# https://codecov.io/ – the other option
- codecov

[dcharkes]

After #13, we have what we need. In a more concise fashion than using the mono_repo generator. So we're just going to stick with the manual workflow file for now.