Use mock response for demo test if Vimeo is down (WordPress#10720)

test/e2e/specs/demo.test.js

@@ -8,6 +8,15 @@ import fetch from 'node-fetch';
  */
 import { visitAdmin } from '../support/utils';
 
+const MOCK_VIMEO_RESPONSE = {
+	url: 'https://vimeo.com/22439234',
+	html: '<iframe width="16" height="9"></iframe>',
+	type: 'video',
+	provider_name: 'Vimeo',
+	provider_url: 'https://vimeo.com',
+	version: '1.0',
+};
+
 describe( 'new editor state', () => {
 	beforeAll( async () => {
 		// Intercept embed requests so that scripts loaded from third parties
@@ -27,13 +36,22 @@ describe( 'new editor state', () => {
 					}
 				);
 				const preview = await response.json();
-				// Remove the first src attribute. This stops the Vimeo iframe loading the actual
-				// embedded content, but the height and width are preserved so layout related
-				// attributes, like aspect ratio CSS classes, remain the same.
-				preview.html = preview.html.replace( /src=[^\s]+/, '' );
+				let responseBody;
+				if ( 'Embed Handler' === preview.provider_name ) {
+					// If Vimeo is down, that would make this test fail. So if we get a
+					// response from 'Embed Handler' instead of 'Vimeo', respond with a mock
+					// response, so we don't hold up development while Vimeo is down.
+					responseBody = MOCK_VIMEO_RESPONSE;
+				} else {
+					// Remove the first src attribute. This stops the Vimeo iframe loading the actual
+					// embedded content, but the height and width are preserved so layout related
+					// attributes, like aspect ratio CSS classes, remain the same.
+					preview.html = preview.html.replace( /src=[^\s]+/, '' );
+					responseBody = preview;
+				}
 				request.respond( {
 					content: 'application/json',
-					body: JSON.stringify( preview ),
+					body: JSON.stringify( responseBody ),
 				} );
 			} else {
 				request.continue();