Parser: Update validateBlock to use fixedBlock

packages/blocks/src/api/parser/fix-custom-classname.js

@@ -42,27 +42,30 @@ export function getHTMLRootElementClasses( innerHTML ) {
  * @return {Object} Filtered block attributes.
  */
 export function fixCustomClassname( blockAttributes, blockType, innerHTML ) {
-	if ( hasBlockSupport( blockType, 'customClassName', true ) ) {
-		// To determine difference, serialize block given the known set of
-		// attributes, with the exception of `className`. This will determine
-		// the default set of classes. From there, any difference in innerHTML
-		// can be considered as custom classes.
-		const { className: omittedClassName, ...attributesSansClassName } =
-			blockAttributes;
-		const serialized = getSaveContent( blockType, attributesSansClassName );
-		const defaultClasses = getHTMLRootElementClasses( serialized );
-		const actualClasses = getHTMLRootElementClasses( innerHTML );
+	if ( ! hasBlockSupport( blockType, 'customClassName', true ) ) {
+		return blockAttributes;
+	}
+
+	const modifiedBlockAttributes = { ...blockAttributes };
+	// To determine difference, serialize block given the known set of
+	// attributes, with the exception of `className`. This will determine
+	// the default set of classes. From there, any difference in innerHTML
+	// can be considered as custom classes.
+	const { className: omittedClassName, ...attributesSansClassName } =
+		modifiedBlockAttributes;
+	const serialized = getSaveContent( blockType, attributesSansClassName );
+	const defaultClasses = getHTMLRootElementClasses( serialized );
+	const actualClasses = getHTMLRootElementClasses( innerHTML );
 
-		const customClasses = actualClasses.filter(
-			( className ) => ! defaultClasses.includes( className )
-		);
+	const customClasses = actualClasses.filter(
+		( className ) => ! defaultClasses.includes( className )
+	);
 
-		if ( customClasses.length ) {
-			blockAttributes.className = customClasses.join( ' ' );
-		} else if ( serialized ) {
-			delete blockAttributes.className;
-		}
+	if ( customClasses.length ) {
+		modifiedBlockAttributes.className = customClasses.join( ' ' );
+	} else if ( serialized ) {
+		delete modifiedBlockAttributes.className;
 	}
 
-	return blockAttributes;
+	return modifiedBlockAttributes;
 }

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

@@ -178,7 +178,7 @@ function applyBlockValidation( unvalidatedBlock, blockType ) {
 	);
 	// Attempt to validate the block once again after the built-in fixes.
 	const [ isFixedValid, validationIssues ] = validateBlock(
-		unvalidatedBlock,
+		fixedBlock,
 		blockType
 	);
 

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

@@ -50,6 +50,38 @@ describe( 'block parser', () => {
 	} );
 
 	describe( 'parseRawBlock', () => {
+		it( 'should apply className block validation fixes', () => {
+			registerBlockType( 'core/test-block', {
+				...defaultBlockSettings,
+				attributes: {
+					fruit: {
+						type: 'string',
+						source: 'text',
+						selector: 'div',
+					},
+				},
+				save: ( { attributes } ) => (
+					// eslint-disable-next-line react/no-unknown-property
+					<div class={ attributes.className }>
+						{ attributes.fruit }
+					</div>
+				),
+			} );
+
+			const block = parseRawBlock( {
+				blockName: 'core/test-block',
+				innerHTML:
+					'<div class="custom-class another-custom-class">Bananas</div>',
+				attrs: { fruit: 'Bananas' },
+			} );
+
+			expect( block.name ).toEqual( 'core/test-block' );
+			expect( block.attributes ).toEqual( {
+				fruit: 'Bananas',
+				className: 'custom-class another-custom-class',
+			} );
+		} );
+
 		it( 'should create the requested block if it exists', () => {
 			registerBlockType( 'core/test-block', defaultBlockSettings );