如何修复预期 $.length = 2 等于 1答案

【问题标题】：How to fix Expected $.length = 2 to equal 1如何修复预期 $.length = 2 等于 1
【发布时间】：2020-06-16 16:28:28
【问题描述】：

我想用 jasmine marble 测试 ngLogger 函数，但是出错了

Expected $.length = 2 to equal 1.

Expected $.length = 2 to equal 1.

Expected $[0].frame = 0 to equal 10.

Expected $[0].notification.value to be a kind of Observable, but was Object({ type: 'TECHNICAL', level: 'ERROR', msg: 'test' }).

Expected $[1] = Object({ frame: 0, notification: Notification({ kind: 'C', value: undefined, error: undefined, hasValue: false }) }) to equal undefined.

测试：

    export namespace GlobalUtils {
       export function ngLogger(error: string): 
                                   Observable<Log> {
        return of({ type: LogEnum.TECHNICAL,
          level: LevelEnum.ERROR,
          msg: error } as Log
        );
      }
    }



    import { GlobalUtils } from './global.utils';

    it('ngLogger should be return an Observable', () => {
        const expected = of({
          type: LogEnum.TECHNICAL,
          level: LevelEnum.ERROR,
          msg: 'test'
        });

        const expected$ = hot('-a', { a: expected });
        const result$ = GlobalUtils.ngLogger('test');

        expect(result$).toBeObservable(expected$);
      });

const expected$ = hot('a', { a: expected }); 没有任何区别。 const expected$ = hot('a|', { a: expected }); 报错：

    Expected $[0].notification.value to be a kind of Observable, but was Object({ type: 'TECHNICAL', level: 'ERROR', msg: 'test' }).
    Expected $[1].frame = 0 to equal 10

然后我改变了

const expected = of({
      type: LogEnum.TECHNICAL,
      level: LevelEnum.ERROR,
      msg: 'test'
    });` to `const expected = of({
      type: LogEnum.TECHNICAL,
      level: LevelEnum.ERROR,
      msg: 'test'
    });

我收到错误Expected $[1].frame = 0 to equal 10. 什么意思？

【问题讨论】：

const expected$ = hot('a', { a: expected }); 甚至const expected$ = hot('a|', { a: expected });?
const expected$ = hot('a', { a: expected }); 没有任何区别。
现在我看到你有两个问题首先是大理石应该是 (a|) 因为这是你描述同时发射和结束可观察的方式，这是在使用 of 时完成的第二个问题是你有你的预期定义为可观察的，它应该只是里面的数据

标签： angular rxjs jasmine-marbles

【解决方案1】：

首先你有两个问题是大理石应该是(a|)，因为这是你描述同时发射和结束可观察的方式，这是在使用of时完成的。第二个问题是您将预期定义为可观察的，它应该只是里面的数据。多亏了这个，我学会了如何使用弹珠：

const msg = 'test';
const expected = {
  type: LogEnum.TECHNICAL,
  level: LevelEnum.ERROR,
  msg,
}; // notice that this value should not be observable

const expected$ = hot('(a|)', { a: expected }); // also you are returning of which is ending immediately

const result$ = GlobalUtils.ngLogger(msg);

expect(result$).toBeObservable(expected$);

这里还有working example

【讨论】：