Merge pull request #7895 from ampproject/fix/pwa-runtime-cache

Eliminate runtime precaching of AMP scripts in Service Worker

.eslintignore

@@ -2,5 +2,4 @@
 **/node_modules/**
 **/vendor/**
 **/assets/js/*.js
-!assets/js/amp-service-worker-runtime-precaching.js
 build/*

.gitignore

@@ -10,7 +10,6 @@ node_modules
 !/assets/css/src/
 /assets/js/**/*.js
 /assets/js/*.asset.php
-!/assets/js/amp-service-worker-runtime-precaching.js
 /assets/js/*.map
 /built
 /amphtml

Gruntfile.js

@@ -53,7 +53,6 @@ module.exports = function (grunt) {
 				src: [
 					'assets/js/**/*.js',
 					'assets/js/**/*.js.map',
-					'!assets/js/amp-service-worker-runtime-precaching.js',
 					'assets/js/**/*.asset.php',
 					'assets/css/*.css',
 					'assets/css/*.css.map',

includes/class-amp-service-worker.php

@@ -111,26 +111,6 @@ public static function add_cdn_script_caching( $service_workers ) {
 			return;
 		}
 
-		// Add AMP scripts to runtime cache which will then get stale-while-revalidate strategy.
-		$service_workers->register(
-			'amp-cdn-runtime-caching',
-			static function() {
-				$urls = AMP_Service_Worker::get_precached_script_cdn_urls();
-				if ( empty( $urls ) ) {
-					return '';
-				}
-
-				$js = file_get_contents( AMP__DIR__ . '/assets/js/amp-service-worker-runtime-precaching.js' ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents, WordPress.WP.AlternativeFunctions.file_system_read_file_get_contents
-				$js = preg_replace( '#/\*\s*global.+?\*/#', '', $js );
-				$js = str_replace(
-					'URLS',
-					wp_json_encode( $urls ),
-					$js
-				);
-				return $js;
-			}
-		);
-
 		// Serve the AMP Runtime from cache and check for an updated version in the background. See <https://github.com/ampproject/amp-by-example/blob/4593af61609898043302a101826ddafe7206bfd9/boilerplate-generator/templates/files/serviceworkerJs.js#L54-L58>.
 		self::register_caching_route(
 			$service_workers,

tests/php/test-class-amp-service-worker.php

@@ -88,16 +88,6 @@ public function test_add_query_var() {
 		$this->assertIsString( $query_vars[1] );
 	}
 
-	/**
-	 * Test add_cdn_script_caching().
-	 *
-	 * @covers \AMP_Service_Worker::add_cdn_script_caching()
-	 */
-	public function test_add_cdn_script_caching() {
-		AMP_Service_Worker::add_cdn_script_caching( wp_service_workers()->get_registry() );
-		$this->assertArrayHasKey( 'amp-cdn-runtime-caching', wp_service_workers()->get_registry()->registered );
-	}
-
 	/**
 	 * Test add_image_caching().
 	 *