cpp-coverage.yml

# *******************************************************************************
# Copyright (c) 2026 Contributors to the Eclipse Foundation
#
# See the NOTICE file(s) distributed with this work for additional
# information regarding copyright ownership.
#
# This program and the accompanying materials are made available under the
# terms of the Apache License Version 2.0 which is available at
# https://www.apache.org/licenses/LICENSE-2.0
#
# SPDX-License-Identifier: Apache-2.0
# *******************************************************************************

name: C++ Coverage

on:
  workflow_call:
    inputs:
      bazel-target:
        description: "Bazel target(s) to run coverage on (supports whitespace/newline separated targets and negative targets)"
        required: false
        default: "//..."
        type: string
      bazel-config:
        description: "Optional Bazel config name (passed via --config=<name>)"
        required: false
        default: ""
        type: string
      extra-bazel-flags:
        description: "Additional Bazel flags to pass to the coverage command (whitespace separated)"
        required: false
        default: ""
        type: string
      runner-label:
        description: "Label of GitHub runner to use (used if REPO_RUNNER_LABELS is not set)"
        required: false
        default: "ubuntu-22.04"
        type: string
      artifact-name-suffix:
        description: "Optional suffix for artifact names (e.g., -v2, -nightly)"
        required: false
        default: ""
        type: string
      genhtml-extra-flags:
        description: "Extra flags to pass to genhtml (whitespace separated; avoid embedded quotes)"
        required: false
        default: ""
        type: string
      retention-days:
        description: "Days to keep uploaded artifacts"
        required: false
        default: 30
        type: number
      min-coverage:
        description: "Minimum line coverage percentage (0 disables check)"
        required: false
        default: 0
        type: number

permissions:
  contents: read

jobs:
  coverage-report:
    name: C++ Coverage
    runs-on: ${{ vars.REPO_RUNNER_LABELS && fromJSON(vars.REPO_RUNNER_LABELS) || inputs.runner-label }}

    steps:
      - name: Checkout repository
        uses: actions/checkout@v6

      - name: Setup Bazel with shared caching
        uses: bazel-contrib/setup-bazel@0.18.0
        with:
          disk-cache: ${{ github.workflow }}
          repository-cache: true
          bazelisk-cache: true
          cache-save: ${{ github.event_name == 'push' && github.ref == 'refs/heads/main' }}

      - name: Install lcov (+ bc for threshold check)
        run: |
          set -euo pipefail
          sudo apt-get update
          sudo apt-get install -y lcov bc

      - name: Run Bazel Coverage
        env:
          BAZEL_CONFIG: ${{ inputs.bazel-config }}
          BAZEL_FLAGS: ${{ inputs.extra-bazel-flags }}
          BAZEL_TARGET: ${{ inputs.bazel-target }}
        run: |
          set -euo pipefail
          set -f  # disable globbing

          cmd=(bazel coverage)

          if [[ -n "${BAZEL_CONFIG}" ]]; then
            cmd+=(--config="${BAZEL_CONFIG}")
          fi

          # split flags/targets on ANY whitespace (spaces/newlines/tabs)
          # shellcheck disable=SC2206
          extra_flags=(${BAZEL_FLAGS})
          if [ ${#extra_flags[@]} -gt 0 ]; then
            cmd+=("${extra_flags[@]}")
          fi

          # shellcheck disable=SC2206
          targets=(${BAZEL_TARGET})
          cmd+=(-- "${targets[@]}")

          echo "Running: ${cmd[*]}"
          "${cmd[@]}"

      - name: Generate HTML Coverage Report
        if: ${{ always() }}
        env:
          GENHTML_EXTRA_FLAGS: ${{ inputs.genhtml-extra-flags }}
        run: |
          set -euo pipefail
          set -f

          output_path="$(bazel info output_path)"
          coverage_dat="${output_path}/_coverage/_coverage_report.dat"

          if [[ ! -f "${coverage_dat}" ]]; then
            echo "::warning::Coverage data not found: ${coverage_dat}"
            exit 0
          fi

          # shellcheck disable=SC2206
          genhtml_flags=(${GENHTML_EXTRA_FLAGS})

          genhtml "${coverage_dat}" \
            -o cpp_coverage \
            --show-details \
            --legend \
            --function-coverage \
            --branch-coverage \
            "${genhtml_flags[@]}"

          cp "${coverage_dat}" coverage.lcov

      - name: Check Coverage Threshold
        if: ${{ always() && inputs.min-coverage > 0 }}
        run: |
          set -euo pipefail

          if [[ ! -f coverage.lcov ]]; then
            echo "::warning::No coverage.lcov found; skipping threshold check"
            exit 0
          fi

          lines_found="$(awk -F: '/^LF:/{sum+=$2} END{print sum+0}' coverage.lcov)"
          lines_hit="$(awk -F: '/^LH:/{sum+=$2} END{print sum+0}' coverage.lcov)"

          if [[ "${lines_found}" -eq 0 ]]; then
            echo "::warning::No lines found in coverage report; skipping threshold check"
            exit 0
          fi

          coverage_percent="$(echo "scale=2; ${lines_hit} * 100 / ${lines_found}" | bc -l)"
          min_coverage="${{ inputs.min-coverage }}"

          echo "Coverage: ${coverage_percent}% (${lines_hit}/${lines_found} lines)"
          echo "Minimum: ${min_coverage}%"

          if (( $(echo "${coverage_percent} < ${min_coverage}" | bc -l) )); then
            echo "::error::Coverage ${coverage_percent}% is below minimum ${min_coverage}%"
            exit 1
          fi

          echo "::notice::Coverage threshold met: ${coverage_percent}% >= ${min_coverage}%"

      - name: Upload coverage artifacts
        if: ${{ always() }}
        uses: actions/upload-artifact@v6
        with:
          name: ${{ format('{0}_cpp_coverage{1}', github.event.repository.name, inputs.artifact-name-suffix) }}
          path: |
            cpp_coverage/
            coverage.lcov
            bazel-testlogs/**/*.log
            bazel-testlogs/**/*.xml
          if-no-files-found: ignore
          retention-days: ${{ inputs.retention-days }}