[Boost] minor cache tweaks (#35616)

* Add .html extension to cache files

* Do not cache empty buffer

* changelog

* Check if is_404 and is_feed can be called before calling them

---------

Co-authored-by: Mark George <[email protected]>

Author: thingalon

projects/plugins/boost/app/modules/cache/Boost_Cache.php

@@ -110,11 +110,11 @@ public function is_cacheable() {
 			return false;
 		}
 
-		if ( function_exists( 'is_404' ) && is_404() ) {
+		if ( Boost_Cache_Utils::is_404() ) {
 			return false;
 		}
 
-		if ( function_exists( 'is_feed' ) && is_feed() ) {
+		if ( Boost_Cache_Utils::is_feed() ) {
 			return false;
 		}
 
@@ -206,7 +206,7 @@ public function ob_start() {
 	 * @return string - The output buffer.
 	 */
 	public function ob_callback( $buffer ) {
-		if ( $this->is_cacheable() ) {
+		if ( strlen( $buffer ) > 0 && $this->is_cacheable() ) {
 			$result = $this->storage->write( $this->request_uri, $this->request_parameters, $buffer );
 
 			if ( is_wp_error( $result ) ) { // phpcs:ignore Generic.CodeAnalysis.EmptyStatement.DetectedIf

projects/plugins/boost/app/modules/cache/Boost_Cache_Utils.php

@@ -3,6 +3,35 @@
 namespace Automattic\Jetpack_Boost\Modules\Page_Cache;
 
 class Boost_Cache_Utils {
+
+	/**
+	 * "Safe" version of WordPress' is_404 method. When called before WordPress' query is run, returns
+	 * `null` (a falsey value) instead of outputting a _doing_it_wrong warning.
+	 */
+	public static function is_404() {
+		global $wp_query;
+
+		if ( ! isset( $wp_query ) || ! function_exists( '\is_404' ) ) {
+			return null;
+		}
+
+		return \is_404();
+	}
+
+	/**
+	 * "Safe" version of WordPress' is_feed method. When called before WordPress' query is run, returns
+	 * `null` (a falsey value) instead of outputting a _doing_it_wrong warning.
+	 */
+	public static function is_feed() {
+		global $wp_query;
+
+		if ( ! isset( $wp_query ) || ! function_exists( '\is_feed' ) ) {
+			return null;
+		}
+
+		return \is_feed();
+	}
+
 	/*
 	 * Recursively delete a directory.
 	 * @param string $dir - The directory to delete.

projects/plugins/boost/app/modules/cache/storage/File_Storage.php

@@ -83,7 +83,7 @@ private function get_request_filename( $request_uri, $parameters ) {
 
 		$key_components = apply_filters( 'boost_cache_key_components', $key_components );
 
-		return md5( json_encode( $key_components ) ); // phpcs:ignore WordPress.WP.AlternativeFunctions.json_encode_json_encode
+		return md5( json_encode( $key_components ) ) . '.html'; // phpcs:ignore WordPress.WP.AlternativeFunctions.json_encode_json_encode
 	}
 
 	/**

projects/plugins/boost/changelog/boost-minor-cache-tweaks

@@ -0,0 +1,5 @@
+Significance: patch
+Type: fixed
+Comment: Fixed minor behavior in pre-release feature
+
+