fix(editor): Return early in ws message handler if no 'command' keyword is found (#7946)

## Summary
Avoid processing websocket messages not n8n sent (filter on 'command'
keyword)

packages/editor-ui/src/components/WorkflowPreview.vue

@@ -136,7 +136,9 @@ const onMouseLeave = () => {
 };
 
 const receiveMessage = ({ data }: MessageEvent) => {
-	if (data?.includes('"command"')) {
+	if (!data?.includes?.('"command"')) {
+		return;
+	}
 	try {
 		const json = JSON.parse(data);
 		if (json.command === 'n8nReady') {
@@ -151,7 +153,6 @@ const receiveMessage = ({ data }: MessageEvent) => {
 	} catch (e) {
 		console.error(e);
 	}
-	}
 };
 const onDocumentScroll = () => {
 	if (insideIframe.value) {

packages/editor-ui/src/components/__tests__/WorkflowPreview.test.ts

@@ -247,4 +247,18 @@ describe('WorkflowPreview', () => {
 			expect(emitted()).toEqual({});
 		});
 	});
+
+	it('should not do anything if no "command" is sent in the message and the `includes` method cannot be applied to the data', async () => {
+		const { emitted } = renderComponent({
+			pinia,
+			props: {},
+		});
+
+		window.postMessage(null, '*');
+
+		await waitFor(() => {
+			expect(console.error).not.toHaveBeenCalled();
+			expect(emitted()).toEqual({});
+		});
+	});
 });

packages/editor-ui/src/views/NodeView.vue

@@ -4312,7 +4312,9 @@ export default defineComponent({
 			}
 		},
 		async onPostMessageReceived(message: MessageEvent) {
-			if (message?.data?.includes('"command"')) {
+			if (!message?.data?.includes?.('"command"')) {
+				return;
+			}
 			try {
 				const json = JSON.parse(message.data);
 				if (json && json.command === 'openWorkflow') {
@@ -4363,7 +4365,6 @@ export default defineComponent({
 					this.workflowsStore.activeWorkflowExecution = json.execution;
 				}
 			} catch (e) {}
-			}
 		},
 		async onImportWorkflowDataEvent(data: IDataObject) {
 			await this.importWorkflowData(data.data as IWorkflowDataUpdate, 'file');