Script Loader: Fix unintended adding of async to scripts that are printed directly with wp_print_scripts() without enqueueing them beforehand.

Props: joemcgill, westonruter, felixarntz, peterwilsoncc.
See: #58648.

git-svn-id: https://develop.svn.wordpress.org/trunk@56092 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-scripts.php

@@ -907,9 +907,19 @@ JS;
 	 * @return string The best eligible loading strategy.
 	 */
 	private function get_eligible_loading_strategy( $handle ) {
-		$eligible = $this->filter_eligible_strategies( $handle );
+		$intended = (string) $this->get_data( $handle, 'strategy' );
 
-		// Bail early once we know the eligible strategy is blocking.
+		// Bail early if there is no intended strategy.
+		if ( ! $intended ) {
+			return '';
+		}
+
+		// If the intended strategy is 'defer', limit the initial list of eligibles.
+		$initial = ( 'defer' === $intended ) ? array( 'defer' ) : null;
+
+		$eligible = $this->filter_eligible_strategies( $handle, $initial );
+
+		// Return early once we know the eligible strategy is blocking.
 		if ( empty( $eligible ) ) {
 			return '';
 		}

tests/phpunit/tests/dependencies/scripts.php

@@ -2931,6 +2931,21 @@ HTML
 		$this->assertSame( $expected, $print_scripts );
 	}
 
+	/**
+	 * Ensure tinymce scripts aren't loading async.
+	 *
+	 * @ticket 58648
+	 */
+	public function test_printing_tinymce_scripts() {
+		global $wp_scripts;
+
+		wp_register_tinymce_scripts( $wp_scripts, true );
+
+		$actual = get_echo( 'wp_print_scripts', array( array( 'wp-tinymce' ) ) );
+
+		$this->assertStringNotContainsString( 'async', $actual );
+	}
+
 	/**
 	 * Parse an HTML markup fragment.
 	 *