import { of } from 'rxjs'; import { publishLast } from 'rxjs/operators'; it('should accept empty parameter', () => { // Here, TypeScript versions 3.1 and earlier infer Observable. However, // the next version infers Observable. It's not possible to specify // an upper bound for the TypeScript version used by dtslint, so an // expectation cannot be applied. const a = of(1, 2, 3).pipe(publishLast()); // $ExpectType Observable }); it('should infer when type is specified', () => { const a = of(1, 2, 3).pipe(publishLast()); // $ExpectType Observable });