Add support for custom non-AMP scripts

composer.json

@@ -14,7 +14,7 @@
     "ext-json": "*",
     "ext-libxml": "*",
     "ext-spl": "*",
-    "ampproject/amp-toolbox": "dev-main#a155c37",
+    "ampproject/amp-toolbox": "dev-add/enforced-css-max-byte-count-transformed-identifier-config#718d9dad",
     "cweagans/composer-patches": "~1.0",
     "fasterimage/fasterimage": "1.5.0",
     "sabberworm/php-css-parser": "dev-master#bfdd976"

includes/amp-helper-functions.php

@@ -1478,6 +1478,11 @@ function amp_get_content_sanitizers( $post = null ) {
 	$native_post_forms_allowed = amp_is_native_post_form_allowed();
 
 	$sanitizers = [
+		// The AMP_Script_Sanitizer runs first because based on whether it allows custom scripts
+		// to be kept, it may impact the behavior of other sanitizers. For example, if custom
+		// scripts are kept then this is a signal that tree shaking in AMP_Style_Sanitizer cannot be
+		// performed.
+		AMP_Script_Sanitizer::class            => [],
 		AMP_Embed_Sanitizer::class             => [
 			'amp_to_amp_linking_enabled' => $amp_to_amp_linking_enabled,
 		],
@@ -1515,8 +1520,9 @@ function amp_get_content_sanitizers( $post = null ) {
 			'native_img_used'   => $native_img_used,
 		],
 		AMP_Block_Sanitizer::class             => [], // Note: Block sanitizer must come after embed / media sanitizers since its logic is using the already sanitized content.
-		AMP_Script_Sanitizer::class            => [],
-		AMP_Style_Sanitizer::class             => [],
+		AMP_Style_Sanitizer::class             => [
+			'skip_tree_shaking' => is_customize_preview(),
+		],
 		AMP_Meta_Sanitizer::class              => [],
 		AMP_Layout_Sanitizer::class            => [],
 		AMP_Accessibility_Sanitizer::class     => [],

includes/class-amp-theme-support.php

@@ -18,6 +18,8 @@
 use AmpProject\Dom\Document;
 use AmpProject\Extension;
 use AmpProject\Optimizer;
+use AmpProject\Optimizer\Configuration\TransformedIdentifierConfiguration;
+use AmpProject\Optimizer\Transformer\TransformedIdentifier;
 use AmpProject\RequestDestination;
 use AmpProject\Tag;
 use AmpProject\AmpWP\Optimizer\Transformer\AmpSchemaOrgMetadata;
@@ -1531,7 +1533,11 @@ public static function ensure_required_markup( Document $dom, $script_handles =
 		}
 
 		// When opting-in to POST forms, omit the amp-form component entirely since it blocks submission.
-		if ( amp_is_native_post_form_allowed() && $dom->xpath->query( '//form[ @action and @method and translate( @method, "POST", "post" ) = "post" ]' )->length > 0 ) {
+		if (
+			in_array( Extension::FORM, $script_handles, true )
+			&&
+			$dom->xpath->query( '//form[ @action and @method and translate( @method, "POST", "post" ) = "post" ]' )->length > 0
+		) {
 			$superfluous_script_handles[] = Extension::FORM;
 		}
 
@@ -2075,6 +2081,9 @@ public static function prepare_response( $response, $args = [] ) {
 			do_action( 'amp_server_timing_start', 'amp_optimizer' );
 
 			$errors = new Optimizer\ErrorCollection();
+
+			// @todo The dev mode attribute is being overloaded here. We should use something else.
+			$args['skip_css_max_byte_count_enforcement'] = $dom->documentElement->hasAttribute( DevMode::DEV_MODE_ATTRIBUTE );
 			self::get_optimizer( $args )->optimizeDom( $dom, $errors );
 
 			if ( count( $errors ) > 0 ) {
@@ -2164,10 +2173,13 @@ static function () use ( $args ) {
 		// Supply the Schema.org metadata, previously obtained just before output buffering began, to the AmpSchemaOrgMetadataConfiguration.
 		add_filter(
 			'amp_optimizer_config',
-			function ( $config ) {
+			function ( $config ) use ( $args ) {
 				if ( is_array( self::$metadata ) ) {
 					$config[ AmpSchemaOrgMetadata::class ][ AmpSchemaOrgMetadataConfiguration::METADATA ] = self::$metadata;
 				}
+				if ( ! empty( $args['skip_css_max_byte_count_enforcement'] ) ) {
+					$config[ TransformedIdentifier::class ][ TransformedIdentifierConfiguration::ENFORCED_CSS_MAX_BYTE_COUNT ] = false;
+				}
 				return $config;
 			},
 			defined( 'PHP_INT_MIN' ) ? PHP_INT_MIN : ~PHP_INT_MAX // phpcs:ignore PHPCompatibility.Constants.NewConstants.php_int_minFound

includes/sanitizers/class-amp-base-sanitizer.php

@@ -140,6 +140,17 @@ public function get_selector_conversion_mapping() {
 		return [];
 	}
 
+	/**
+	 * Update args.
+	 *
+	 * Merges the supplied args with the existing args.
+	 *
+	 * @param array $args Args.
+	 */
+	public function update_args( $args ) {
+		$this->args = array_merge( $this->args, $args );
+	}
+
 	/**
 	 * Run logic before any sanitizers are run.
 	 *