ci: test against the latest Gutenberg plugin

.github/workflows/test-plugin-gutenberg.yml

@@ -0,0 +1,63 @@
+name: Test Plugin (Gutenberg)
+
+# Runs the unit tests with the latest Gutenberg plugin active, to catch block
+# changes before they reach a WordPress release. Kept out of `test-plugin.yml`
+# so a Gutenberg breakage never blocks the Release workflow, which calls it.
+
+on:
+  pull_request:
+    paths-ignore:
+      - '**/*.md'
+  schedule:
+    - cron: '17 6 * * *'
+  workflow_dispatch:
+
+concurrency:
+  group: test-plugin-gutenberg-${{ github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+jobs:
+  test_plugin_gutenberg:
+    runs-on: ubuntu-22.04
+    name: WordPress 7.1 + Gutenberg, PHP 8.3
+    env:
+      PHP_VERSION: '8.3'
+      WP_VERSION: '7.1'
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v7
+
+      - name: Create Docker Containers
+        env:
+          DOCKER_BUILDKIT: 1
+          COMPOSE_DOCKER_CLI_BUILD: 1
+        run: |
+          docker compose build \
+            --build-arg WP_VERSION="$WP_VERSION" \
+            --build-arg PHP_VERSION="$PHP_VERSION"
+          docker compose up -d
+
+      - name: Wait for db
+        run: |
+          while ! mysqladmin ping --host=127.0.0.1 --port=33066 --password="$MYSQL_ROOT_PASSWORD" --silent; do
+            sleep 1
+          done
+
+      - name: Setup testing framework
+        run: docker exec "$(docker compose ps -q wordpress)" init-testing-environment.sh
+
+      - name: Install and activate WP GraphQL
+        run: docker exec --workdir=/var/www/html/wp-content/plugins/wp-graphql-content-blocks "$(docker compose ps -q wordpress)" wp plugin install wp-graphql --activate --allow-root
+
+      # The test bootstrap loads it when WP_TESTS_LOAD_GUTENBERG is set.
+      - name: Install Gutenberg
+        run: docker exec --workdir=/var/www/html/wp-content/plugins/wp-graphql-content-blocks "$(docker compose ps -q wordpress)" wp plugin install gutenberg --allow-root
+
+      - name: Install Dependencies
+        run: docker exec -w /var/www/html/wp-content/plugins/wp-graphql-content-blocks "$(docker compose ps -q wordpress)" composer install
+
+      - name: Run unit tests
+        run: docker exec -e WP_TESTS_LOAD_GUTENBERG=1 -w /var/www/html/wp-content/plugins/wp-graphql-content-blocks "$(docker compose ps -q wordpress)" composer test

tests/bootstrap.php

@@ -23,7 +23,11 @@
 
 tests_add_filter( 'wp_loaded', '_output_wp_version' );
 function _output_wp_version() {
-	echo 'Running on WordPress ' . esc_html( get_bloginfo( 'version' ) ) . "...\n";
+	echo 'Running on WordPress ' . esc_html( get_bloginfo( 'version' ) );
+	if ( defined( 'GUTENBERG_VERSION' ) ) {
+		echo ' with Gutenberg ' . esc_html( GUTENBERG_VERSION );
+	}
+	echo "...\n";
 }
 
 tests_add_filter( 'muplugins_loaded', '_manually_load_plugin' );
@@ -39,6 +43,11 @@ function _manually_load_plugin() {
 
 	// Load WP-GraphQL
 	require_once WP_TEST_PLUGINS_DIR . '/wp-graphql/wp-graphql.php';
+
+	// Load the Gutenberg plugin when asked to, to test against unreleased block changes.
+	if ( getenv( 'WP_TESTS_LOAD_GUTENBERG' ) ) {
+		require_once WP_TEST_PLUGINS_DIR . '/gutenberg/gutenberg.php';
+	}
 }
 
 require $_tests_dir . '/includes/bootstrap.php';