Bail early in createUpgradedEmbedBlock for invalid block types (#15885)

* Bail early in createUpgradedEmbedBlock if block type does not exists

* Add changelog entry

* Add tests

packages/block-library/CHANGELOG.md

@@ -1,3 +1,7 @@
+## Master
+
+- Fixed an issue with creating upgraded embed blocks that are not registered ([#15883](https://github.com/WordPress/gutenberg/issues/15883)).
+
 ## 2.5.0 (2019-05-21)
 
 - Add vertical alignment controls to Columns Block ([#13899](https://github.com/WordPress/gutenberg/pull/13899/)).

packages/block-library/src/embed/test/index.js

@@ -3,11 +3,16 @@
  */
 import { render } from 'enzyme';
 
+/**
+ * WordPress dependencies
+ */
+import { registerBlockType, unregisterBlockType } from '@wordpress/blocks';
+
 /**
  * Internal dependencies
  */
 import { getEmbedEditComponent } from '../edit';
-import { findBlock, getClassNames } from '../util';
+import { findBlock, getClassNames, createUpgradedEmbedBlock } from '../util';
 
 describe( 'core/embed', () => {
 	test( 'block edit matches snapshot', () => {
@@ -44,4 +49,29 @@ describe( 'core/embed', () => {
 		const expected = 'lovely';
 		expect( getClassNames( html, 'lovely wp-embed-aspect-16-9 wp-has-aspect-ratio', false ) ).toEqual( expected );
 	} );
+
+	test( 'createUpgradedEmbedBlock bails early when block type does not exist', () => {
+		const youtubeURL = 'https://www.youtube.com/watch?v=dQw4w9WgXcQ';
+
+		expect( createUpgradedEmbedBlock( { attributes: { url: youtubeURL } }, {} ) ).toBeUndefined();
+	} );
+
+	test( 'createUpgradedEmbedBlock returns a YouTube embed block when given a YouTube URL', () => {
+		const youtubeURL = 'https://www.youtube.com/watch?v=dQw4w9WgXcQ';
+
+		registerBlockType(
+			'core-embed/youtube',
+			{
+				title: 'YouTube',
+				category: 'embed',
+			}
+		);
+
+		const result = createUpgradedEmbedBlock( { attributes: { url: youtubeURL } }, {} );
+
+		unregisterBlockType( 'core-embed/youtube' );
+
+		expect( result ).not.toBeUndefined();
+		expect( result.name ).toBe( 'core-embed/youtube' );
+	} );
 } );

packages/block-library/src/embed/util.js

@@ -15,7 +15,7 @@ import memoize from 'memize';
  * WordPress dependencies
  */
 import { renderToString } from '@wordpress/element';
-import { createBlock } from '@wordpress/blocks';
+import { createBlock, getBlockType } from '@wordpress/blocks';
 
 /**
  * Returns true if any of the regular expressions match the URL.
@@ -82,6 +82,10 @@ export const createUpgradedEmbedBlock = ( props, attributesFromPreview ) => {
 
 	const matchingBlock = findBlock( url );
 
+	if ( ! getBlockType( matchingBlock ) ) {
+		return;
+	}
+
 	// WordPress blocks can work on multiple sites, and so don't have patterns,
 	// so if we're in a WordPress block, assume the user has chosen it for a WordPress URL.
 	if ( WORDPRESS_EMBED_BLOCK !== name && DEFAULT_EMBED_BLOCK !== matchingBlock ) {