Block Example: Avoid a crash when block is not registered (#55686)

* Block Example: Avoid a crash when block is not registered

* Use a try-catch statement

packages/blocks/src/api/factory.js

@@ -580,11 +580,19 @@ export function switchToBlockType( blocks, name ) {
  * @return {Object} block.
  */
 export const getBlockFromExample = ( name, example ) => {
-	return createBlock(
-		name,
-		example.attributes,
-		( example.innerBlocks ?? [] ).map( ( innerBlock ) =>
-			getBlockFromExample( innerBlock.name, innerBlock )
-		)
-	);
+	try {
+		return createBlock(
+			name,
+			example.attributes,
+			( example.innerBlocks ?? [] ).map( ( innerBlock ) =>
+				getBlockFromExample( innerBlock.name, innerBlock )
+			)
+		);
+	} catch {
+		return createBlock( 'core/missing', {
+			originalName: name,
+			originalContent: '',
+			originalUndelimitedContent: '',
+		} );
+	}
 };

packages/blocks/src/api/test/factory.js

@@ -17,6 +17,7 @@ import {
 	findTransform,
 	isWildcardBlockTransform,
 	isContainerGroupBlock,
+	getBlockFromExample,
 } from '../factory';
 import {
 	getBlockType,
@@ -2276,4 +2277,33 @@ describe( 'block factory', () => {
 			expect( isContainerGroupBlock( 'core/group' ) ).toBe( false );
 		} );
 	} );
+
+	describe( 'getBlockFromExample', () => {
+		it( 'should replace unregistered block with core/missing block', () => {
+			registerBlockType( 'core/missing', {
+				title: 'Unsupported',
+			} );
+			registerBlockType( 'core/paragraph', {
+				title: 'Paragraph',
+			} );
+			registerBlockType( 'core/group', {
+				title: 'A block that groups other blocks.',
+			} );
+			const example = {
+				innerBlocks: [
+					{ name: 'core/paragraph' },
+					{ name: 'core/image' },
+				],
+			};
+			expect(
+				getBlockFromExample( 'core/group', example )
+			).toMatchObject( {
+				name: 'core/group',
+				innerBlocks: [
+					{ name: 'core/paragraph' },
+					{ name: 'core/missing' },
+				],
+			} );
+		} );
+	} );
 } );