browser-tests.yml

name: Browser Performance Tests

on:
    pull_request:
        types: [opened, synchronize, reopened]

permissions:
    contents: read
    pull-requests: write

jobs:
    test-changed-packages:
        strategy:
            matrix:
                browser: [firefox, chrome]
        name: Compare performance to latest release on ${{ matrix.browser }}

        # The job will only run if the pull request is from the same repository.
        # Benchmarks can't run on PRs from forked repos due to comment posting restrictions without a GitHub token.
        if: ${{ github.event.pull_request.head.repo.full_name == github.repository }}
        runs-on: ubuntu-22.04
        steps:
            - name: Checkout main
              uses: actions/checkout@v4
              with:
                  ref: main

            - name: Checkout PR branch
              uses: actions/checkout@v4
              with:
                  fetch-depth: 0 # Get full history

            - name: Fetch main branch
              run: |
                  git fetch origin main:main

            - name: Setup Job and Install Dependencies
              uses: ./.github/actions/setup-job

            - name: Check ChromeDriver Version
              if: matrix.browser == 'chrome'
              run: |
                  echo "Checking ChromeDriver version..."
                  npx chromedriver --version
                  echo "Checking Chrome version..."
                  google-chrome --version
                  echo "Checking tachometer chromedriver version..."
                  yarn tachometer --version

            - name: Tachometer the changed packages
              run: yarn test:changed --browser=${{ matrix.browser }}

            - name: Create a dummy file to ensure at least one results file exists
              run: touch tachometer.${{ matrix.browser }}-ran.txt

            - name: Archive ${{ matrix.browser }} tachometer results
              id: upload-artifact
              uses: actions/upload-artifact@v4
              with:
                  name: tachometer-results-${{ matrix.browser }}
                  path: |
                      tach-results.${{ matrix.browser }}.*.json
                      tachometer.${{ matrix.browser }}-ran.txt

    comment-performance:
        name: Comment tachometer performance results
        needs: [test-changed-packages]

        # The job will only run if the pull request is from the same repository.
        # Benchmarks can't run on PRs from forked repos due to comment posting restrictions without a GitHub token.
        if: ${{ github.event.pull_request == null || github.event.pull_request.head.repo.full_name == github.repository }}
        runs-on: ubuntu-latest
        steps:
            - name: Checkout main
              uses: actions/checkout@v4
              with:
                  ref: main

            - name: Checkout PR branch
              uses: actions/checkout@v4
              with:
                  fetch-depth: 2

            - name: Setup Job and Install Dependencies
              uses: ./.github/actions/setup-job

            - uses: actions/download-artifact@v4
              with:
                  pattern: tachometer-results-*
                  merge-multiple: true

            - name: Post Tachometer Performance Comment
              uses: actions/github-script@v7
              with:
                  script: |
                      const { buildTachometerComment } = await import('${{ github.workspace }}/tasks/build-tachometer-comment.js');
                      const body = buildTachometerComment();
                      const { commentOrUpdate } = await import('${{ github.workspace }}/tasks/comment-or-update.js');
                      commentOrUpdate(github, context, '## Tachometer results', body);