Try reducing specificity of global styles selectors only. (#60106)

Co-authored-by: tellthemachines <[email protected]> Co-authored-by: MaggieCabrera <[email protected]> Co-authored-by: aaronrobertshaw <[email protected]>
WordPress · Mar 26, 2024 · e408f73 · e408f73
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commit e408f73
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Showing 5 changed files with 42 additions and 40 deletions.
diff --git a/lib/class-wp-theme-json-gutenberg.php b/lib/class-wp-theme-json-gutenberg.php
@@ -2680,7 +2680,7 @@ static function ( $pseudo_selector ) use ( $selector ) {
 		}
 
 		// 2. Generate and append the rules that use the general selector.
-		$block_rules .= static::to_ruleset( $selector, $declarations );
+		$block_rules .= static::to_ruleset( ":where($selector)", $declarations );
 
 		// 3. Generate and append the rules that use the duotone selector.
 		if ( isset( $block_metadata['duotone'] ) && ! empty( $declarations_duotone ) ) {
@@ -2697,7 +2697,7 @@ static function ( $pseudo_selector ) use ( $selector ) {
 
 		// 5. Generate and append the feature level rulesets.
 		foreach ( $feature_declarations as $feature_selector => $individual_feature_declarations ) {
-			$block_rules .= static::to_ruleset( $feature_selector, $individual_feature_declarations );
+			$block_rules .= static::to_ruleset( ":where($feature_selector)", $individual_feature_declarations );
 		}
 
 		// 6. Generate and append the style variation rulesets.

diff --git a/packages/block-editor/src/components/global-styles/test/use-global-styles-output.js b/packages/block-editor/src/components/global-styles/test/use-global-styles-output.js
@@ -481,8 +481,8 @@ describe( 'global styles renderer', () => {
 
 			expect( toStyles( tree, blockSelectors ) ).toEqual(
 				'body {margin: 0;}body .is-layout-flow > .alignleft { float: left; margin-inline-start: 0; margin-inline-end: 2em; }body .is-layout-flow > .alignright { float: right; margin-inline-start: 2em; margin-inline-end: 0; }body .is-layout-flow > .aligncenter { margin-left: auto !important; margin-right: auto !important; }body .is-layout-constrained > .alignleft { float: left; margin-inline-start: 0; margin-inline-end: 2em; }body .is-layout-constrained > .alignright { float: right; margin-inline-start: 2em; margin-inline-end: 0; }body .is-layout-constrained > .aligncenter { margin-left: auto !important; margin-right: auto !important; }body .is-layout-constrained > :where(:not(.alignleft):not(.alignright):not(.alignfull)) { max-width: var(--wp--style--global--content-size); margin-left: auto !important; margin-right: auto !important; }body .is-layout-constrained > .alignwide { max-width: var(--wp--style--global--wide-size); }body .is-layout-flex { display:flex; }body .is-layout-flex { flex-wrap: wrap; align-items: center; }body .is-layout-flex > * { margin: 0; }body .is-layout-grid { display:grid; }body .is-layout-grid > * { margin: 0; }' +
-					'body{background-color: red;margin: 10px;padding: 10px;}a:where(:not(.wp-element-button)){color: blue;}a:where(:not(.wp-element-button)):hover{color: orange;}a:where(:not(.wp-element-button)):focus{color: orange;}h1{font-size: 42px;}.wp-block-group{margin-top: 10px;margin-right: 20px;margin-bottom: 30px;margin-left: 40px;padding-top: 11px;padding-right: 22px;padding-bottom: 33px;padding-left: 44px;}h1,h2,h3,h4,h5,h6{color: orange;}h1 a:where(:not(.wp-element-button)),h2 a:where(:not(.wp-element-button)),h3 a:where(:not(.wp-element-button)),h4 a:where(:not(.wp-element-button)),h5 a:where(:not(.wp-element-button)),h6 a:where(:not(.wp-element-button)){color: hotpink;}h1 a:where(:not(.wp-element-button)):hover,h2 a:where(:not(.wp-element-button)):hover,h3 a:where(:not(.wp-element-button)):hover,h4 a:where(:not(.wp-element-button)):hover,h5 a:where(:not(.wp-element-button)):hover,h6 a:where(:not(.wp-element-button)):hover{color: red;}h1 a:where(:not(.wp-element-button)):focus,h2 a:where(:not(.wp-element-button)):focus,h3 a:where(:not(.wp-element-button)):focus,h4 a:where(:not(.wp-element-button)):focus,h5 a:where(:not(.wp-element-button)):focus,h6 a:where(:not(.wp-element-button)):focus{color: red;}' +
-					'.wp-block-image img, .wp-block-image .wp-crop-area{border-radius: 9999px;}.wp-block-image{color: red;}.wp-site-blocks > .alignleft { float: left; margin-right: 2em; }.wp-site-blocks > .alignright { float: right; margin-left: 2em; }.wp-site-blocks > .aligncenter { justify-content: center; margin-left: auto; margin-right: auto; }' +
+					':where(body){background-color: red;margin: 10px;padding: 10px;}:where(a:where(:not(.wp-element-button))){color: blue;}a:where(:not(.wp-element-button)):hover{color: orange;}a:where(:not(.wp-element-button)):focus{color: orange;}:where(h1){font-size: 42px;}:where(.wp-block-group){margin-top: 10px;margin-right: 20px;margin-bottom: 30px;margin-left: 40px;padding-top: 11px;padding-right: 22px;padding-bottom: 33px;padding-left: 44px;}:where(h1,h2,h3,h4,h5,h6){color: orange;}:where(h1 a:where(:not(.wp-element-button)),h2 a:where(:not(.wp-element-button)),h3 a:where(:not(.wp-element-button)),h4 a:where(:not(.wp-element-button)),h5 a:where(:not(.wp-element-button)),h6 a:where(:not(.wp-element-button))){color: hotpink;}h1 a:where(:not(.wp-element-button)):hover,h2 a:where(:not(.wp-element-button)):hover,h3 a:where(:not(.wp-element-button)):hover,h4 a:where(:not(.wp-element-button)):hover,h5 a:where(:not(.wp-element-button)):hover,h6 a:where(:not(.wp-element-button)):hover{color: red;}h1 a:where(:not(.wp-element-button)):focus,h2 a:where(:not(.wp-element-button)):focus,h3 a:where(:not(.wp-element-button)):focus,h4 a:where(:not(.wp-element-button)):focus,h5 a:where(:not(.wp-element-button)):focus,h6 a:where(:not(.wp-element-button)):focus{color: red;}' +
+					':where(.wp-block-image img, .wp-block-image .wp-crop-area){border-radius: 9999px;}:where(.wp-block-image){color: red;}.wp-site-blocks > .alignleft { float: left; margin-right: 2em; }.wp-site-blocks > .alignright { float: right; margin-left: 2em; }.wp-site-blocks > .aligncenter { justify-content: center; margin-left: auto; margin-right: auto; }' +
 					'.has-white-color{color: var(--wp--preset--color--white) !important;}.has-white-background-color{background-color: var(--wp--preset--color--white) !important;}.has-white-border-color{border-color: var(--wp--preset--color--white) !important;}.has-black-color{color: var(--wp--preset--color--black) !important;}.has-black-background-color{background-color: var(--wp--preset--color--black) !important;}.has-black-border-color{border-color: var(--wp--preset--color--black) !important;}h1.has-blue-color,h2.has-blue-color,h3.has-blue-color,h4.has-blue-color,h5.has-blue-color,h6.has-blue-color{color: var(--wp--preset--color--blue) !important;}h1.has-blue-background-color,h2.has-blue-background-color,h3.has-blue-background-color,h4.has-blue-background-color,h5.has-blue-background-color,h6.has-blue-background-color{background-color: var(--wp--preset--color--blue) !important;}h1.has-blue-border-color,h2.has-blue-border-color,h3.has-blue-border-color,h4.has-blue-border-color,h5.has-blue-border-color,h6.has-blue-border-color{border-color: var(--wp--preset--color--blue) !important;}'
 			);
 		} );
@@ -524,7 +524,7 @@ describe( 'global styles renderer', () => {
 
 			expect( toStyles( Object.freeze( tree ), blockSelectors ) ).toEqual(
 				'body {margin: 0;}body .is-layout-flow > .alignleft { float: left; margin-inline-start: 0; margin-inline-end: 2em; }body .is-layout-flow > .alignright { float: right; margin-inline-start: 2em; margin-inline-end: 0; }body .is-layout-flow > .aligncenter { margin-left: auto !important; margin-right: auto !important; }body .is-layout-constrained > .alignleft { float: left; margin-inline-start: 0; margin-inline-end: 2em; }body .is-layout-constrained > .alignright { float: right; margin-inline-start: 2em; margin-inline-end: 0; }body .is-layout-constrained > .aligncenter { margin-left: auto !important; margin-right: auto !important; }body .is-layout-constrained > :where(:not(.alignleft):not(.alignright):not(.alignfull)) { max-width: var(--wp--style--global--content-size); margin-left: auto !important; margin-right: auto !important; }body .is-layout-constrained > .alignwide { max-width: var(--wp--style--global--wide-size); }body .is-layout-flex { display:flex; }body .is-layout-flex { flex-wrap: wrap; align-items: center; }body .is-layout-flex > * { margin: 0; }body .is-layout-grid { display:grid; }body .is-layout-grid > * { margin: 0; }' +
-					'.wp-image-spacing{padding-top: 1px;}.wp-image-border-color{border-color: red;}.wp-image-border{border-radius: 9999px;}.wp-image{color: red;}' +
+					':where(.wp-image-spacing){padding-top: 1px;}:where(.wp-image-border-color){border-color: red;}:where(.wp-image-border){border-radius: 9999px;}:where(.wp-image){color: red;}' +
 					'.wp-site-blocks > .alignleft { float: left; margin-right: 2em; }.wp-site-blocks > .alignright { float: right; margin-left: 2em; }.wp-site-blocks > .aligncenter { justify-content: center; margin-left: auto; margin-right: auto; }'
 			);
 		} );

diff --git a/packages/block-editor/src/components/global-styles/use-global-styles-output.js b/packages/block-editor/src/components/global-styles/use-global-styles-output.js
@@ -844,7 +844,7 @@ export const toStyles = (
 					( [ cssSelector, declarations ] ) => {
 						if ( declarations.length ) {
 							const rules = declarations.join( ';' );
-							ruleset += `${ cssSelector }{${ rules };}`;
+							ruleset += `:where(${ cssSelector }){${ rules };}`;
 						}
 					}
 				);
@@ -937,7 +937,9 @@ export const toStyles = (
 				isTemplate
 			);
 			if ( declarations?.length ) {
-				ruleset += `${ selector }{${ declarations.join( ';' ) };}`;
+				ruleset += `:where(${ selector }){${ declarations.join(
+					';'
+				) };}`;
 			}
 
 			// Check for pseudo selector in `styles` and handle separately.

diff --git a/packages/block-editor/src/components/iframe/index.js b/packages/block-editor/src/components/iframe/index.js
@@ -244,12 +244,12 @@ function Iframe( {
 				height: auto !important;
 				min-height: 100%;
 			}
-
-			body {
+			/* Lowest specificity to not override global styles */
+			:where(body) {
 				margin: 0;
 				/* Default background color in case zoom out mode background
 				colors the html element */
-				background: white;
+				background-color: white;
 			}
 		</style>
 		${ styles }