Changeset 61008 for trunk/tests/phpunit/tests/theme/wpAddGlobalStylesForBlocks.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/theme/wpAddGlobalStylesForBlocks.php (modified) (2 diffs)

trunk/tests/phpunit/tests/theme/wpAddGlobalStylesForBlocks.php

@@ -288 +288 @@
      * @ticket 56915
      * @ticket 61165
+     *
+     * @covers ::wp_add_global_styles_for_blocks
      */
     public function test_blocks_inline_styles_get_rendered() {
+        // Override wp_load_classic_theme_block_styles_on_demand().
+        add_filter( 'should_load_block_assets_on_demand', '__return_false' ); // Needed for the .wp-block-post-featured-image assertion below.
+
         $this->set_up_third_party_block();
         wp_register_style( 'global-styles', false, array(), true, true );
@@ -312 +317 @@
      * @ticket 57868
      * @ticket 61165
+     *
+     * @covers ::wp_add_global_styles_for_blocks
      */
     public function test_third_party_blocks_inline_styles_for_elements_get_rendered_when_per_block() {
         $this->set_up_third_party_block();
         add_filter( 'should_load_separate_core_block_assets', '__return_true' );
+        $this->assertTrue( wp_should_load_separate_core_block_assets(), 'Core assets are expected to load separately' );
 
         wp_register_style( 'global-styles', false, array(), true, true );