[DEV-11477] Validate layout property using isEnum

Author: inf1nite-lo0p

packages/content-format/src/nodes/EmbedNode.ts

@@ -1,6 +1,6 @@
 import { OEmbedInfo as OEmbed } from '../common';
 import { Element } from '../Element';
-import { isNonEmptyString, isUuid } from '../validation';
+import { isEnum, isNonEmptyString, isUuid } from '../validation';
 
 export interface EmbedNode extends Element<typeof EmbedNode.TYPE> {
     uuid: string;
@@ -28,6 +28,7 @@ export namespace EmbedNode {
         const isValid =
             isEmbedNode(value) &&
             isNonEmptyString(value.url) &&
+            isEnum(value.layout, Layout) &&
             isUuid(value.uuid) &&
             OEmbed.isOEmbedInfo(value.oembed);