Run browser tests to collect code coverage data

.github/workflows/coverage_browser_tests.yml

@@ -0,0 +1,99 @@
+name: Coverage (Browser tests)
+on:
+  push:
+    paths:
+      - 'gulpfile.mjs'
+      - 'external/builder/**'
+      - 'src/**'
+      - 'test/images/**'
+      - 'test/pdfs/**'
+      - 'test/resources/**'
+      - 'test/*.css'
+      - 'test/driver.js'
+      - 'test/test.mjs'
+      - 'test/test_manifest.json'
+      - 'test/test_slave.html'
+      - 'web/**'
+      - '.github/workflows/coverage_browser_tests.yml'
+    branches:
+      - master
+  pull_request:
+    paths:
+      - 'gulpfile.mjs'
+      - 'external/builder/**'
+      - 'src/**'
+      - 'test/images/**'
+      - 'test/pdfs/**'
+      - 'test/resources/**'
+      - 'test/*.css'
+      - 'test/driver.js'
+      - 'test/test.mjs'
+      - 'test/test_manifest.json'
+      - 'test/test_slave.html'
+      - 'web/**'
+      - '.github/workflows/coverage_browser_tests.yml'
+    branches:
+      - master
+  workflow_dispatch:
+permissions:
+  contents: read
+
+jobs:
+  test:
+    name: ${{ matrix.os }} / firefox
+
+    strategy:
+      fail-fast: false
+      matrix:
+        node-version: [lts/*]
+        os: [ubuntu-latest]
+
+    runs-on: ${{ matrix.os }}
+    environment: code-coverage
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          fetch-depth: 0
+          persist-credentials: false
+
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+        with:
+          node-version: ${{ matrix.node-version }}
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Restore cached PDF files
+        uses: actions/cache/restore@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
+        with:
+          path: test/pdfs/*.pdf
+          key: cached-pdf-files-${{ hashFiles('test/pdfs/*.pdf') }}
+          restore-keys: |
+            cached-pdf-files-
+          enableCrossOsArchive: true
+
+      - name: Run browser tests with code coverage
+        run: npx gulp botbrowsertest --headless -j$(nproc) --coverage --coverage-output build/coverage/browser --noChrome
+
+      - name: Save cached PDF files
+        uses: actions/cache/save@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
+        with:
+          path: test/pdfs/*.pdf
+          key: cached-pdf-files-${{ hashFiles('test/pdfs/*.pdf') }}
+          enableCrossOsArchive: true
+
+      - name: Upload results to Codecov
+        uses: codecov/codecov-action@e79a6962e0d4c0c17b229090214935d2e33f8354 # v6.0.1
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          fail_ci_if_error: true
+          files: ./build/coverage/browser/lcov.info
+          flags: browsertest
+          name: codecov-umbrella
+          disable_search: true
+          disable_telem: true
+          verbose: true