Add conditional delays to auth-next (#2934)

* Add conditional delays to auth-next

* [AUTOMATED]: Prettier Code Styling

* Use typescript asserts keyword for typesafe assertions

* [AUTOMATED]: Prettier Code Styling

* Rebase conflicts & PR feedback

* More PR Feedback

* Strip debug asserts from prod builds

* [AUTOMATED]: Prettier Code Styling

* [AUTOMATED]: API Reports

* Fix logic in assertion

* Revert merge artifacts

* PR Feedback

Author: avolkovi

packages-exp/auth-exp/src/api/index.ts

@@ -27,6 +27,7 @@ import {
   ServerError,
   ServerErrorMap
 } from './errors';
+import { Delay } from '../core/util/delay';
 
 export enum HttpMethod {
   POST = 'POST',

packages-exp/auth-exp/src/core/user/user_impl.ts

@@ -49,6 +49,16 @@ function assertStringOrUndefined(
   );
 }
 
+function assertStringOrUndefined(
+  assertion: unknown,
+  appName: string
+): asserts assertion is string | undefined {
+  assert(
+    typeof assertion === 'string' || typeof assertion === 'undefined',
+    appName
+  );
+}
+
 export class UserImpl implements User {
   // For the user object, provider is always Firebase.
   readonly providerId = externs.ProviderId.FIREBASE;