coverage.yml

# This workflow runs code coverage using cargo-llvm-cov + cargo-nextest and uploads as GitHub artifact
# No external services required

name: Coverage

on:
  push:
    branches: [ main ]
  pull_request:
    branches: [ main ]

jobs:
  coverage:
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Add llvm-tools component
        run: rustup component add llvm-tools-preview

      - name: Install cargo-llvm-cov and cargo-nextest
        uses: taiki-e/install-action@v2
        with:
          tool: cargo-llvm-cov,nextest

      - name: Collect coverage data
        run: |
          cargo llvm-cov nextest \
            --workspace \
            --exclude loadtest \
            --exclude migration \
            --profile ci \
            --no-report

      - name: Generate coverage reports
        run: |
          cargo llvm-cov report --lcov --output-path lcov.info
          cargo llvm-cov report --html --output-dir target/coverage/html

      - name: Extract coverage percentage
        id: coverage
        run: |
          COVERAGE=$(cargo llvm-cov report --summary-only | grep -oP '\d+\.\d+(?=%)' | tail -1)
          echo "percentage=$COVERAGE" >> $GITHUB_OUTPUT
          echo "Coverage: $COVERAGE%"

      - name: Upload HTML coverage artifact
        uses: actions/upload-artifact@v4
        with:
          name: coverage-html-${{ github.sha }}
          path: target/coverage/html/

      - name: Upload LCOV coverage artifact
        uses: actions/upload-artifact@v4
        with:
          name: coverage-lcov-${{ github.sha }}
          path: lcov.info

      - name: Comment coverage on PR
        if: github.event_name == 'pull_request'
        uses: actions/github-script@v7
        with:
          script: |
            const coverage = '${{ steps.coverage.outputs.percentage }}';
            const comment = `## Coverage Report

            **Current Coverage: ${coverage}%**

            📊 [View detailed HTML report](../../actions/runs/${{ github.run_id }})

            Target: 60-80% coverage`;

            github.rest.issues.createComment({
              issue_number: context.issue.number,
              owner: context.repo.owner,
              repo: context.repo.repo,
              body: comment
            });