Add html5lib tests input and steps.

Author: costdev

.github/workflows/reusable-phpunit-tests.yml

@@ -34,6 +34,11 @@ on:
         description: 'Whether to test with memcached enabled'
         required: false
         type: 'boolean'
+        default:
+      html5lib-tests:
+        description: 'Whether to run the html5lib tests'
+        required: false
+        type: 'boolean'
         default: false
       phpunit-config:
         description: 'The PHPUnit configuration file to use'
@@ -169,6 +174,21 @@ jobs:
         if: ${{ ! inputs.multisite }}
         run: node ./tools/local-env/scripts/docker.js run php ./vendor/bin/phpunit --verbose -c ${{ env.PHPUNIT_CONFIG }} --group external-http
 
+      - name: Check if the HTML API was modified
+        id: check-for-html-api-changes
+        if: {{ inputs.html5lib-tests }}
+        uses: tj-actions/changed-files@v44
+        with:
+          files: |
+            src/wp-includes/html-api/**.php
+            tests/phpunit/tests/html-api/wpHtmlProcessorHtml5lib.php
+            tests/phpunit/data/html5lib-tests/**.dat
+            .github/workflows/html5lib-tests.yml
+
+      - name: Run html5lib tests
+        if: {{ inputs.html5lib-tests && steps.check-for-html-api-changes.outputs.any_changed == 'true' }}
+        run: node ./tools/local-env/scripts/docker.js run php ./vendor/bin/phpunit --verbose -c ${{ env.PHPUNIT_CONFIG }} --group html-api-html5lib-tests
+
       # __fakegroup__ is excluded to force PHPUnit to ignore the <exclude> settings in phpunit.xml.dist.
       - name: Run (Xdebug) tests
         if: ${{ inputs.php != '8.3' }}