Block Supports: Avoid throwing warning when checking for class attribute as string.

dmsnell · dmsnell · commit 1ebc4c5ea516 · 2025-09-10T20:25:46.000Z
When encountering HTML tags with boolean or missing tags, the get_attribute() method in the HTML API returns true and null, respectively. If these returned values are sent directly into string comparison functions then as of PHP 8.0 they will throw E_DEPRECATED errors. In this patch, block supports is enhanced to check that the class value is a string before it performs string operations on it. Also in this patch: using `assertEqualHTML()` in background support test instead of `assertSame()` Developed in #5486 Discussed in https://core.trac.wordpress.org/ticket/59622 Props dmsnell, jonsurrell, hellofromtonya, peterwilsoncc. Fixes #59622. git-svn-id: https://develop.svn.wordpress.org/trunk@60727 602fd350-edb4-49c9-b593-d223f7449a82
diff --git a/src/wp-includes/block-supports/background.php b/src/wp-includes/block-supports/background.php
@@ -87,16 +87,13 @@ function wp_render_background_support( $block_content, $block ) {
 
 		if ( $tags->next_tag() ) {
 			$existing_style = $tags->get_attribute( 'style' );
-			$updated_style  = '';
-
-			if ( ! empty( $existing_style ) ) {
-				$updated_style = $existing_style;
-				if ( ! str_ends_with( $existing_style, ';' ) ) {
-					$updated_style .= ';';
-				}
+			if ( is_string( $existing_style ) && '' !== $existing_style ) {
+				$separator     = str_ends_with( $existing_style, ';' ) ? '' : ';';
+				$updated_style = "{$existing_style}{$separator}{$styles['css']}";
+			} else {
+				$updated_style = $styles['css'];
 			}
 
-			$updated_style .= $styles['css'];
 			$tags->set_attribute( 'style', $updated_style );
 			$tags->add_class( 'has-background' );
 		}
diff --git a/tests/phpunit/tests/block-supports/layout.php b/tests/phpunit/tests/block-supports/layout.php
@@ -184,7 +184,7 @@ public function test_outer_container_not_restored_for_aligned_image_block_with_t
 	public function test_layout_support_flag_renders_classnames_on_wrapper( $args, $expected_output ) {
 		switch_theme( 'default' );
 		$actual_output = wp_render_layout_support_flag( $args['block_content'], $args['block'] );
-		$this->assertSame( $expected_output, $actual_output );
+		$this->assertEqualHTML( $expected_output, $actual_output );
 	}
 
 	/**
diff --git a/tests/phpunit/tests/block-supports/wpRenderBackgroundSupport.php b/tests/phpunit/tests/block-supports/wpRenderBackgroundSupport.php
@@ -186,6 +186,21 @@ public function data_background_block_support() {
 				'expected_wrapper'    => '<div class="wp-block-test has-background" style="color: red;font-size: 15px;background-image:url(&#039;https://example.com/image.jpg&#039;);background-size:cover;">Content</div>',
 				'wrapper'             => '<div class="wp-block-test" style="color: red;font-size: 15px;">Content</div>',
 			),
+			'background image style is appended if a boolean style attribute already exists' => array(
+				'theme_name'          => 'block-theme-child-with-fluid-typography',
+				'block_name'          => 'test/background-rules-are-output',
+				'background_settings' => array(
+					'backgroundImage' => true,
+				),
+				'background_style'    => array(
+					'backgroundImage' => array(
+						'url'    => 'https://example.com/image.jpg',
+						'source' => 'file',
+					),
+				),
+				'expected_wrapper'    => '<div class="has-background" classname="wp-block-test" style="background-image:url(&#039;https://example.com/image.jpg&#039;);background-size:cover;">Content</div>',
+				'wrapper'             => '<div classname="wp-block-test" style>Content</div>',
+			),
 			'background image style is not applied if the block does not support background image' => array(
 				'theme_name'          => 'block-theme-child-with-fluid-typography',
 				'block_name'          => 'test/background-rules-are-not-output',

Original file line number	Diff line number	Diff line change
`@@ -184,7 +184,7 @@ public function test_outer_container_not_restored_for_aligned_image_block_with_t`
`184`	`184`	`public function test_layout_support_flag_renders_classnames_on_wrapper( $args, $expected_output ) {`
`185`	`185`	`switch_theme( 'default' );`
`186`	`186`	`$actual_output = wp_render_layout_support_flag( $args['block_content'], $args['block'] );`
`187`		`- $this->assertSame( $expected_output, $actual_output );`
	`187`	`+ $this->assertEqualHTML( $expected_output, $actual_output );`
`188`	`188`	`}`
`189`	`189`
`190`	`190`	`/**`