@cats-cradle/rush-coverage

RushCoverage is a code coverage consolidation tool for RushJs based monorepos.

It consolidates code coverage reports from multiple projects into one report. This allows for one coverage badge to cover the entire monorepo or one badge to coverage each team, etc. as to help promote team ownership of code base.

This can be useful for continuous integration purposes. It can also be useful for simultaneously browsing coverage html, et al. reports for the entire repo.

Usage

Beforehand, use Jest (or similar) to generate **/**/coverage/coverage-final.json coverage reports for each project.

Now that it's ready, run the script to merge coverage files from all projects into a single report:

npx @cats-cradle/[email protected]

Note Make sure the version of @microsoft/rush-lib specified in rush.json matches the dependencies specified in this package.

That's it! The consolidated code coverage reports are generated to cwd ./coverage. Reports can reviewed manually or integrated into CI.

Github Action

This is an example of how to use a Github Action, RushCoverage, and third party -- in this case Codacy -- to generate code coverage in CI.

See vendor specific documentation for instructions on coverage submission, badging, pr feedback, etc.

name: CodeCoverage

on:
  workflow_call:
    secrets:
      CODACY_PROJECT_TOKEN:
        required: true

jobs:
  rush-coverage:
    name: rush coverage
    timeout-minutes: 15
    runs-on: ubuntu-latest
    steps:
      - name: checkout repository
        uses: actions/checkout@v3

      - name: Setup Node
        uses: actions/setup-node@v3
        with:
          node-version: '18.12.0'

      - name: Rush install
        run: node common/scripts/install-run-rush.js install

      - name: Rush build
        run: node common/scripts/install-run-rush.js build

      - name: Rush test with coverage
        run: node common/scripts/install-run-rush.js test:cov

      - name: Merge coverage reports
        run: npx @cats-cradle/[email protected]

      - name: Submit merged coverage report
        uses: codacy/[email protected]
        with:
          project-token: ${{ secrets.CODACY_PROJECT_TOKEN }}
          coverage-reports: coverage/lcov.info

Note Change test:cov command as specific to your monorepo setup. Set secrets, in this case CODACY_PROJECT_TOKEN, as necessary in Github.

How it Works

RushCoverage works by obtaining a list of all projects from rush.json. Then gather a list of all coverage files from each project with a compatible ./coverage/coverage-final.json . It then combines all the coverage files found into one consolidated coverage report.