From 9956c90e2d27f2183be41471cf42275f0b51585f Mon Sep 17 00:00:00 2001
From: Weston Ruter <westonruter@google.com>
Date: Thu, 14 Nov 2019 23:15:38 -0800
Subject: [PATCH] Implement method to get all extension_specs

---
 bin/amphtml-update.py                           | 17 +++++++++++++++++
 includes/amp-helper-functions.php               | 13 +++----------
 includes/class-amp-theme-support.php            |  3 ++-
 .../class-amp-allowed-tags-generated.php        | 17 +++++++++++++++++
 4 files changed, 39 insertions(+), 11 deletions(-)

diff --git a/bin/amphtml-update.py b/bin/amphtml-update.py
index 07dd23af353..1948c4cb592 100644
--- a/bin/amphtml-update.py
+++ b/bin/amphtml-update.py
@@ -211,6 +211,23 @@ def GenerateFooterPHP(out):
 		return self::$allowed_tags;
 	}
 
+	/**
+	 * Get extension specs.
+	 *
+	 * @since 1.5
+	 * @internal
+	 * @return array Extension specs, keyed by extension name.
+	 */
+	public static function get_extension_specs() {
+		$extension_specs = [];
+		foreach ( self::get_allowed_tag( 'script' ) as $script_spec ) {
+			if ( isset( $script_spec[ AMP_Rule_Spec::TAG_SPEC ]['extension_spec'] ) ) {
+				$extension_specs[ $script_spec[ AMP_Rule_Spec::TAG_SPEC ]['extension_spec']['name'] ] = $script_spec[ AMP_Rule_Spec::TAG_SPEC ]['extension_spec'];
+			}
+		}
+		return $extension_specs;
+	}
+
 	/**
 	 * Get allowed tag.
 	 *
diff --git a/includes/amp-helper-functions.php b/includes/amp-helper-functions.php
index 69adbf8e148..91394bfc453 100644
--- a/includes/amp-helper-functions.php
+++ b/includes/amp-helper-functions.php
@@ -465,26 +465,19 @@ function amp_register_default_scripts( $wp_scripts ) {
 	);
 
 	// Register all AMP components as defined in the spec.
-	foreach ( AMP_Allowed_Tags_Generated::get_allowed_tag( 'script' ) as $script_spec ) {
-		if ( ! isset( $script_spec[ AMP_Rule_Spec::TAG_SPEC ]['extension_spec'] ) ) {
-			continue;
-		}
-		$extension_spec = $script_spec[ AMP_Rule_Spec::TAG_SPEC ]['extension_spec'];
-
+	foreach ( AMP_Allowed_Tags_Generated::get_extension_specs() as $extension_name => $extension_spec ) {
 		$src = sprintf(
 			'https://cdn.ampproject.org/v0/%s-%s.js',
-			$extension_spec['name'],
+			$extension_name,
 			end( $extension_spec['version'] )
 		);
 
 		$wp_scripts->add(
-			$extension_spec['name'],
+			$extension_name,
 			$src,
 			[ 'amp-runtime' ],
 			null
 		);
-
-		$wp_scripts->add_data( $extension_spec['name'], 'amp_requires_usage', ! empty( $extension_spec['requires_usage'] ) );
 	}
 
 	if ( $wp_scripts->query( 'amp-carousel', 'registered' ) ) {
diff --git a/includes/class-amp-theme-support.php b/includes/class-amp-theme-support.php
index 3fd1e650d40..e881f72f8b0 100644
--- a/includes/class-amp-theme-support.php
+++ b/includes/class-amp-theme-support.php
@@ -1746,12 +1746,13 @@ public static function ensure_required_markup( DOMDocument $dom, $script_handles
 		}
 
 		// Remove scripts that had already been added but couldn't be detected from output buffering.
+		$extension_specs            = AMP_Allowed_Tags_Generated::get_extension_specs();
 		$superfluous_script_handles = array_diff(
 			array_keys( $amp_scripts ),
 			array_merge( $script_handles, [ 'amp-runtime' ] )
 		);
 		foreach ( $superfluous_script_handles as $superfluous_script_handle ) {
-			if ( true === wp_scripts()->get_data( $superfluous_script_handle, 'amp_requires_usage' ) ) {
+			if ( ! empty( $extension_specs[ $superfluous_script_handle ]['requires_usage'] ) ) {
 				unset( $amp_scripts[ $superfluous_script_handle ] );
 			}
 		}
diff --git a/includes/sanitizers/class-amp-allowed-tags-generated.php b/includes/sanitizers/class-amp-allowed-tags-generated.php
index 3f3c62e0088..be5345bde8e 100644
--- a/includes/sanitizers/class-amp-allowed-tags-generated.php
+++ b/includes/sanitizers/class-amp-allowed-tags-generated.php
@@ -17595,6 +17595,23 @@ public static function get_allowed_tags() {
 		return self::$allowed_tags;
 	}
 
+	/**
+	 * Get extension specs.
+	 *
+	 * @since 1.5
+	 * @internal
+	 * @return array Extension specs, keyed by extension name.
+	 */
+	public static function get_extension_specs() {
+		$extension_specs = [];
+		foreach ( self::get_allowed_tag( 'script' ) as $script_spec ) {
+			if ( isset( $script_spec[ AMP_Rule_Spec::TAG_SPEC ]['extension_spec'] ) ) {
+				$extension_specs[ $script_spec[ AMP_Rule_Spec::TAG_SPEC ]['extension_spec']['name'] ] = $script_spec[ AMP_Rule_Spec::TAG_SPEC ]['extension_spec'];
+			}
+		}
+		return $extension_specs;
+	}
+
 	/**
 	 * Get allowed tag.
 	 *