import { throwError, animationFrameScheduler } from 'rxjs'; it('should accept any type and return never observable', () => { const a = throwError(1); // $ExpectType Observable const b = throwError('a'); // $ExpectType Observable const c = throwError({a: 1}); // $ExpectType Observable }); it('should support scheduler', () => { const a = throwError(1, animationFrameScheduler); // $Expect Observable });