add test for wp_use_placeholder_for_delayed_css()

sjapaget · sjapaget · commit 2b8841572cc7 · 2025-10-16T23:52:05.000+02:00
diff --git a/tests/phpunit/tests/template.php b/tests/phpunit/tests/template.php
@@ -851,6 +851,47 @@ public function test_wp_always_load_block_styles_on_demand_init_in_classic_theme
 		$this->assertTrue( true == has_action( 'wp_template_enhancement_output_buffer_started', 'wp_use_placeholder_for_delayed_css' ), 'Expect wp_template_enhancement_output_buffer_started filter to be added for classic themes.' );
 	}
 
+	/**
+	 * Tests that wp_use_placeholder_for_delayed_css adds a placeholder for delayed CSS, then removes it and adds all CSS to the head including late enqueued styles.
+	 *
+	 * @ticket 64099
+	 * @covers ::wp_use_placeholder_for_delayed_css
+	 */
+	public function test_wp_use_placeholder_for_delayed_css(): void {
+		
+		// Enqueue a style
+		wp_enqueue_style( 'test-style', 'http://example.com/style.css' );
+		
+		wp_use_placeholder_for_delayed_css();
+		
+		// Simulate wp_head
+		ob_start();
+		do_action( 'wp_head' );
+		$head_output = ob_get_clean();
+		
+		$this->assertMatchesRegularExpression( '/<!--late_styles:[a-f0-9-]{36}-->/', $head_output, 'Expect the placeholder to be present' );
+		$this->assertStringContainsString( 'test-style', $head_output, 'Expect the enqueued stylesheet to be present' );
+		
+		// Enqueue a late style (after wp_head)
+		wp_enqueue_style( 'test-late-style', 'http://example.com/late-style.css' );
+		
+		// Simulate footer scripts
+		ob_start();
+		do_action( 'wp_print_footer_scripts' );
+		$footer_output = ob_get_clean();
+		
+		// Create a complete HTML buffer
+		$buffer = '<html><head>' . $head_output . '</head><body>Content' . $footer_output . '</body></html>';
+		
+		// Apply the output buffer filter
+		$filtered_buffer = apply_filters( 'wp_template_enhancement_output_buffer', $buffer );
+		
+		preg_match( '/<head>(.+?)<\/head>/s', $filtered_buffer, $head_matches );
+		$this->assertNotEmpty( $head_matches, 'Expect the late enqueued styles to be present in the header' );
+		$this->assertStringContainsString( 'test-late-style', $head_matches[1], 'Expect the late enqueued styles to be present in the header' );
+		$this->assertStringNotContainsString( '<!--late_styles:', $filtered_buffer, 'Expect the placeholder to be gone' );
+	}
+
 	public function assertTemplateHierarchy( $url, array $expected, $message = '' ) {
 		$this->go_to( $url );
 		$hierarchy = $this->get_template_hierarchy();
