Uncaught SyntaxError: Identifier 'eventMap' has already been declared

I think it might be unrelated but the only change I made recently was adding this:

resolve(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<any> | Promise<any> | any {
  return forkJoin([
    this._userService.getMe(),
    this._businessService.getAll()
  ]).pipe(
    tap(([user, businesses]) => {
      this._appState.user = user;
      this._appState.businesses = businesses;
    }));
}

This is part of a Resolve<any> implementation which I use in order to pre-load data on a route:

{
  path : '',
  // ..
  resolve: {applicationData: ApplicationResolver}
}

In any case, no matter which page, I get the following error on the first page load:

dom-testing-library-event.js:1 Uncaught SyntaxError: Identifier 'eventMap' has already been declared
    at VM17509 dom-testing-library-event.js:1
(anonymous) @ dom-testing-library-event.js:1

There's not any further information so.. any ideas?

It doesn't seem to do any harm (so far) but I would like to know what that is ..

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