Changeset 61008 for trunk/tests/phpunit/tests/dependencies/styles.php

Timestamp:

10/21/2025 05:59:38 AM (3 months ago)

Author:

westonruter

Message:

Script Loader: Load block styles on demand in classic themes via the template enhancement output buffer.

• This applies in classic themes when a site has not opted out of the template enhancement buffer by filtering wp_should_output_buffer_template_for_enhancement off.
• Both should_load_separate_core_block_assets and should_load_block_assets_on_demand are filtered on, as otherwise they are only enabled by default in block themes.
• Any style enqueued after wp_head and printed via print_late_styles() will get hoisted up to be inserted right after the wp-block-library inline style in the HEAD.
• The result is a >10% benchmarked improvement in LCP for core classic themes due to a ~100KB reduction in the amount of CSS unconditionally being served with every page load.

Developed in ​https://github.com/WordPress/wordpress-develop/pull/10288

Follow-up to [60936].

Props sjapaget, westonruter, peterwilsoncc, dmsnell, mindctrl.
See #43258.
Fixes #64099.

File:

• trunk/tests/phpunit/tests/dependencies/styles.php (modified) (2 diffs)

trunk/tests/phpunit/tests/dependencies/styles.php

@@ -437 +437 @@
      */
     public function test_block_styles_for_editing_with_theme_support() {
+        // Override wp_load_classic_theme_block_styles_on_demand().
+        add_filter( 'should_load_separate_core_block_assets', '__return_false' );
+
         add_theme_support( 'wp-block-styles' );
 
@@ -473 +476 @@
      */
     public function test_block_styles_for_viewing_with_theme_support() {
+        // Override wp_load_classic_theme_block_styles_on_demand().
+        add_filter( 'should_load_separate_core_block_assets', '__return_false' );
+
         add_theme_support( 'wp-block-styles' );