Use jq to print only the percentages of coverage from a json-summary file to markdown in github actions - jestjs

Question

I want to pretty print my json-coverage jest results to github actions. I have a ci.yml file with the following:
- name: Run Unit Tests
run: |
yarn test:next:unit --runInBand --coverage --coverageReporters="text-summary"
- name: Echo Coverage
run: |
cat coverage/coverage-summary.json | head -1 > coverage-testing/coverage.json
This prints the first line of jest's coverage-summary in the job terminal and it looks like this:
{"total": {"lines":{"total":18326,"covered":11,"skipped":0,"pct":0.06},"statements":{"total":62625,"covered":11,"skipped":0,"pct":0.01},"functions":{"total":19047,"covered":4,"skipped":0,"pct":0.02},"branches":{"total":60202,"covered":11,"skipped":0,"pct":0.01},"branchesTrue":{"total":0,"covered":0,"skipped":0,"pct":100}}
}
I can print this directly to my github action run in the UI by adding this to the ci.yml:
- name: Print to github
run: cat coverage-testing/coverage.json >> $GITHUB_STEP_SUMMARY
and it shows up in github action run under annotations
jest-next summary
{"total": {"lines":{"total":52,"covered":11,"skipped":0,"pct":21.15},"statements":{"total":54,"covered":11,"skipped":0,"pct":20.37},"functions":{"total":16,"covered":4,"skipped":0,"pct":25},"branches":{"total":18,"covered":11,"skipped":0,"pct":61.11},"branchesTrue":{"total":0,"covered":0,"skipped":0,"pct":100}}
Job summary generated at run-time
Now for the pretty printing. I've tried some various jq commands including iterating with to_entries in a way that would make the github action job summary look more like markdown. I got errors because the array was nested and I got those errors to go away by changing -r to -R and adding try, but then nothing printed to github. Since these attempts are all in CI and the jest tests are flaky, changing one thing and waiting is getting cumbersome. Does anyone happen to have a script that does this already? Not picky about how it's formatted, I'd just like it to look less like json and more like markdown.

Answer 1

You can pretty quickly present it as a list of path/value pairs by streaming in the input. You could then join the paths to a more readable form and dump it.
$ jq -r --stream 'select(length == 2)|"\(.[0]|join("_")): \t\(.[1])"' input.json
total_lines_total: 18326
total_lines_covered: 11
total_lines_skipped: 0
total_lines_pct: 0.06
total_statements_total: 62625
total_statements_covered: 11
total_statements_skipped: 0
total_statements_pct: 0.01
total_functions_total: 19047
total_functions_covered: 4
total_functions_skipped: 0
total_functions_pct: 0.02
total_branches_total: 60202
total_branches_covered: 11
total_branches_skipped: 0
total_branches_pct: 0.01
total_branchesTrue_total: 0
total_branchesTrue_covered: 0
total_branchesTrue_skipped: 0
total_branchesTrue_pct: 100
If you want to retain some structure, you'll need to decide on that first...