hunk.code_window:               const value = x instanceof Observable ? this.materializeInnerObservable(x, this.frame) : x;
                 flushTest.expected!.push({ frame: this.frame, notification: nextNotification(value) });
               },
               (error) => {
                 flushTest.expected!.push({ frame: this.frame, notification: errorNotification(error) });
               },
  
hunk.labels: keep keep keep replace keep keep
hunk.after_edit:             error: (error) => {
  
hunk.file_path: src/internal/testing/TestScheduler.ts
hunk.type: replace
file: import { of } from 'rxjs';
  import { buffer } from 'rxjs/operators';
  
  it('should infer correctly', () => {
    const o = of(1, 2, 3).pipe(buffer(of('foo'))); // $ExpectType Observable<number[]>
  });
  
  it('should enforce types', () => {
    const o = of(1, 2, 3).pipe(buffer()); // $ExpectError
    const p = of(1, 2, 3).pipe(buffer(6)); // $ExpectError
  });
  