如何模拟用户在rxjs TestScheduler单元测试中经过一段时间后触发取消订阅？

Question

使用rxjs TestScheduler，我具有以下工作单元测试：

import { TestScheduler } from 'rxjs/testing';


it('test', () => {
    testScheduler.run(helpers => {

        const { expectObservable } = helpers;
        const expectedMarbles = 'a 999ms b 999ms (c|)';

        const expectedValues = {
          a: undefined,
          b: returnedValue1,
          c: returnedValue2
        };

        const rtiDataSource: RealTimeDataSource = TestBed.get(RealTimeDataSource);

        rtiDataSource.init(RTIConfig.rtiConfig);

        const result = rtiDataSource.observe(tennantId, jwt);

        expectObservable(result.Observable).toBe(expectedMarbles, expectedValues);

    });
}

这一切都按预期进行。我还有一个额外的工作流程，如果用户取消订阅，则会触发其他操作。这样实现：

$requestPipe: Observable<any> = //main polling functionality
        .pipe(
           finalize(() => {
               //cleaning up logic here...
           })
         );    

return $requestPipe;

我需要测试此功能。因此，我要执行的操作是使用TestScheduler触发测试，然后在第一个发射后我要unsubscribe。像这样的东西：

testScheduler.run(helpers => {

    const { expectObservable } = helpers;
    const expectedMarbles = 'a 999ms |';
    //                               ^ unsubscribe would happen here and stop emitting 

    const expectedValues = {
      a: undefined,
    };

    const rtiDataSource: RealTimeDataSource = TestBed.get(RealTimeDataSource);

    rtiDataSource.init(RTIConfig.rtiConfig);

    const result = rtiDataSource.observe(tennantId, jwt);

    setTimeout(() => {

      result.Unsubscribe();

    }, (1000));

    expectObservable(result.Observable).toBe(expectedMarbles, expectedValues);

});

但是在此示例中，setTimeout没有运行，因为TestScheduler使用的是“虚拟时间”。那么如何测试此功能？

Answer 1

最后非常简单，TestScheduler库给我留下了深刻的印象。如果您遇到这种问题，我会推荐reading the docs。

该库支持语法来指定订阅开始和结束的时间，因此您可以非常简单地模拟我的方案：

testScheduler.run(helpers => {

    const { expectObservable } = helpers;
    const expectedMarbles = '   a 999ms -';
    const subscritionMarbles = '^ 999ms !';
    //simulate the subscription ^       ^ simulate the unsubscription

    const expectedValues = {
      a: undefined,
    };

    const rtiDataSource: RealTimeDataSource = TestBed.get(RealTimeDataSource);

    rtiDataSource.init(RTIConfig.rtiConfig);

    const result = rtiDataSource.observe(tennantId, jwt);

    expectObservable(result.Observable, subscritionMarbles).toBe(expectedMarbles, expectedValues);
    // pass subscritionMarbles into the expectObservable

});