Navigation: Load the raw property on the navigation fallback

lib/compat/wordpress-6.3/navigation-fallback.php

@@ -26,10 +26,17 @@ function gutenberg_add_fields_to_navigation_fallback_embeded_links( $schema ) {
 	$schema['properties']['content']['context'] = array_merge( $schema['properties']['content']['context'], array( 'embed' ) );
 
 	// Expose sub properties of content field.
+	// These aren't exposed by the posts controller by default, see:
+	// https://github.com/WordPress/wordpress-develop/blob/5c3c6258e468c67ba00bbd13db29994f1a57a52a/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php#L2425.
 	$schema['properties']['content']['properties']['raw']['context']           = array_merge( $schema['properties']['content']['properties']['raw']['context'], array( 'embed' ) );
 	$schema['properties']['content']['properties']['rendered']['context']      = array_merge( $schema['properties']['content']['properties']['rendered']['context'], array( 'embed' ) );
 	$schema['properties']['content']['properties']['block_version']['context'] = array_merge( $schema['properties']['content']['properties']['block_version']['context'], array( 'embed' ) );
 
+	// Expose sub properties of title field.
+	// These aren't exposed by the posts controller by default, see:
+	// https://github.com/WordPress/wordpress-develop/blob/5c3c6258e468c67ba00bbd13db29994f1a57a52a/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php#L2401.
+	$schema['properties']['title']['properties']['raw']['context'] = array_merge( $schema['properties']['title']['properties']['raw']['context'], array( 'embed' ) );
+
 	return $schema;
 }
 

phpunit/class-gutenberg-rest-navigation-fallback-controller-test.php

@@ -157,6 +157,46 @@ public function test_prepare_item() {
 		// Covered by the core test.
 	}
 
+	/**
+	 * Tests that the correct filters are applied to the context parameter.
+	 *
+	 * By default, the REST response for the Posts Controller will not return all fields
+	 * when the context is set to 'embed'. Assert that correct additional fields are added
+	 * to the embedded Navigation Post, when the navigation fallback endpoint
+	 * is called with the `_embed` param.
+	 *
+	 * @covers wp_add_fields_to_navigation_fallback_embeded_links
+	 */
+	public function test_embedded_navigation_post_contains_required_fields() {
+		// First we'll use the navigation fallback to get a link to the navigation endpoint.
+		$request  = new WP_REST_Request( 'GET', '/wp-block-editor/v1/navigation-fallback' );
+		$response = rest_get_server()->dispatch( $request );
+		$links    = $response->get_links();
+
+		// Extract the navigation endpoint URL from the response.
+		$embedded_navigation_href = $links['self'][0]['href'];
+		preg_match( '/\?rest_route=(.*)/', $embedded_navigation_href, $matches );
+		$navigation_endpoint = $matches[1];
+
+		// Fetch the "linked" navigation post from the endpoint, with the context parameter set to 'embed' to simulate fetching embedded links.
+		$request = new WP_REST_Request( 'GET', $navigation_endpoint );
+		$request->set_param( 'context', 'embed' );
+		$response = rest_get_server()->dispatch( $request );
+		$data     = $response->get_data();
+
+		// Verify that the additional status field is present.
+		$this->assertArrayHasKey( 'status', $data, 'Response title should contain a "status" field.' );
+
+		// Verify that the additional content fields are present.
+		$this->assertArrayHasKey( 'content', $data, 'Response should contain a "content" field.' );
+		$this->assertArrayHasKey( 'raw', $data['content'], 'Response content should contain a "raw" field.' );
+		$this->assertArrayHasKey( 'rendered', $data['content'], 'Response content should contain a "rendered" field.' );
+		$this->assertArrayHasKey( 'block_version', $data['content'], 'Response should contain a "block_version" field.' );
+
+		// Verify that the additional title.raw field is present.
+		$this->assertArrayHasKey( 'raw', $data['title'], 'Response title should contain a "raw" key.' );
+	}
+
 	/**
 	 * @doesNotPerformAssertions
 	 */