fix(feedback): Check for empty user (#11993)

When getting the user from the scope, the user can also be an empty
object, which doesn't work with null coalescing. This checks to see if
the user exists and that it's not empty in all scopes

Fixes getsentry/sentry#70347

packages/feedback/src/modal/integration.tsx

@@ -5,12 +5,26 @@ import type {
   FeedbackFormData,
   FeedbackModalIntegration,
   IntegrationFn,
+  User,
 } from '@sentry/types';
 import { h, render } from 'preact';
 import { DOCUMENT } from '../constants';
 import { Dialog } from './components/Dialog';
 import { createDialogStyles } from './components/Dialog.css';
 
+function getUser(): User | undefined {
+  const currentUser = getCurrentScope().getUser();
+  const isolationUser = getIsolationScope().getUser();
+  const globalUser = getGlobalScope().getUser();
+  if (currentUser && Object.keys(currentUser).length) {
+    return currentUser;
+  }
+  if (isolationUser && Object.keys(isolationUser).length) {
+    return isolationUser;
+  }
+  return globalUser;
+}
+
 export const feedbackModalIntegration = ((): FeedbackModalIntegration => {
   return {
     name: 'FeedbackModal',
@@ -19,7 +33,7 @@ export const feedbackModalIntegration = ((): FeedbackModalIntegration => {
     createDialog: ({ options, screenshotIntegration, sendFeedback, shadow }: CreateDialogProps) => {
       const shadowRoot = shadow as unknown as ShadowRoot;
       const userKey = options.useSentryUser;
-      const user = getCurrentScope().getUser() || getIsolationScope().getUser() || getGlobalScope().getUser();
+      const user = getUser();
 
       const el = DOCUMENT.createElement('div');
       const style = createDialogStyles();