Block support: Preserve aria-label value in comment delimiter

packages/block-editor/src/hooks/aria-label.js

@@ -4,13 +4,6 @@
 import { addFilter } from '@wordpress/hooks';
 import { hasBlockSupport } from '@wordpress/blocks';
 
-const ARIA_LABEL_SCHEMA = {
-	type: 'string',
-	source: 'attribute',
-	attribute: 'aria-label',
-	selector: '*',
-};
-
 /**
  * Filters registered block settings, extending attributes with ariaLabel using aria-label
  * of the first node.
@@ -28,7 +21,9 @@ export function addAttribute( settings ) {
 		// Gracefully handle if settings.attributes is undefined.
 		settings.attributes = {
 			...settings.attributes,
-			ariaLabel: ARIA_LABEL_SCHEMA,
+			ariaLabel: {
+				type: 'string',
+			},
 		};
 	}
 

packages/blocks/src/api/parser/apply-built-in-validation-fixes.js

@@ -2,6 +2,7 @@
  * Internal dependencies
  */
 import { fixCustomClassname } from './fix-custom-classname';
+import { fixAriaLabel } from './fix-aria-label';
 
 /**
  * Attempts to fix block invalidation by applying build-in validation fixes
@@ -15,11 +16,22 @@ import { fixCustomClassname } from './fix-custom-classname';
  * @return {WPBlock} Fixed block object
  */
 export function applyBuiltInValidationFixes( block, blockType ) {
-	const updatedBlockAttributes = fixCustomClassname(
-		block.attributes,
+	const { attributes, originalContent } = block;
+	let updatedBlockAttributes = attributes;
+
+	// Fix block invalidation for className attribute.
+	updatedBlockAttributes = fixCustomClassname(
+		attributes,
+		blockType,
+		originalContent
+	);
+	// Fix block invalidation for ariaLabel attribute.
+	updatedBlockAttributes = fixAriaLabel(
+		updatedBlockAttributes,
 		blockType,
-		block.originalContent
+		originalContent
 	);
+
 	return {
 		...block,
 		attributes: updatedBlockAttributes,

packages/blocks/src/api/parser/fix-aria-label.js

@@ -0,0 +1,51 @@
+/**
+ * Internal dependencies
+ */
+import { hasBlockSupport } from '../registration';
+import { parseWithAttributeSchema } from './get-block-attributes';
+
+const ARIA_LABEL_ATTR_SCHEMA = {
+	type: 'string',
+	source: 'attribute',
+	selector: '[data-aria-label] > *',
+	attribute: 'aria-label',
+};
+
+/**
+ * Given an HTML string, returns the aria-label attribute assigned to
+ * the root element in the markup.
+ *
+ * @param {string} innerHTML Markup string from which to extract the aria-label.
+ *
+ * @return {string} The aria-label assigned to the root element.
+ */
+export function getHTMLRootElementAriaLabel( innerHTML ) {
+	const parsed = parseWithAttributeSchema(
+		`<div data-aria-label>${ innerHTML }</div>`,
+		ARIA_LABEL_ATTR_SCHEMA
+	);
+	return parsed;
+}
+
+/**
+ * Given a parsed set of block attributes, if the block supports ariaLabel
+ * and an aria-label attribute is found, the aria-label attribute is assigned
+ * to the block attributes.
+ *
+ * @param {Object} blockAttributes Original block attributes.
+ * @param {Object} blockType       Block type settings.
+ * @param {string} innerHTML       Original block markup.
+ *
+ * @return {Object} Filtered block attributes.
+ */
+export function fixAriaLabel( blockAttributes, blockType, innerHTML ) {
+	if ( ! hasBlockSupport( blockType, 'ariaLabel', false ) ) {
+		return blockAttributes;
+	}
+	const modifiedBlockAttributes = { ...blockAttributes };
+	const ariaLabel = getHTMLRootElementAriaLabel( innerHTML );
+	if ( ariaLabel ) {
+		modifiedBlockAttributes.ariaLabel = ariaLabel;
+	}
+	return modifiedBlockAttributes;
+}

packages/blocks/src/api/parser/test/index.js

@@ -82,6 +82,39 @@ describe( 'block parser', () => {
 			} );
 		} );
 
+		it( 'should apply aria-label block validation fixes', () => {
+			registerBlockType( 'core/test-block', {
+				...defaultBlockSettings,
+				attributes: {
+					fruit: {
+						type: 'string',
+						source: 'text',
+						selector: 'div',
+					},
+				},
+				supports: {
+					ariaLabel: true,
+				},
+				save: ( { attributes } ) => (
+					<div aria-label={ attributes.ariaLabel }>
+						{ attributes.fruit }
+					</div>
+				),
+			} );
+
+			const block = parseRawBlock( {
+				blockName: 'core/test-block',
+				innerHTML: '<div aria-label="custom-label">Bananas</div>',
+				attrs: { fruit: 'Bananas' },
+			} );
+
+			expect( block.name ).toEqual( 'core/test-block' );
+			expect( block.attributes ).toEqual( {
+				fruit: 'Bananas',
+				ariaLabel: 'custom-label',
+			} );
+		} );
+
 		it( 'should create the requested block if it exists', () => {
 			registerBlockType( 'core/test-block', defaultBlockSettings );