BehaviorSubject流单元测试，实际数据失败

import { BehaviorSubject } from 'rxjs';

describe('BehaviorSubject', () => {
  let subject: BehaviorSubject<number>;

  beforeEach(() => {
    subject = new BehaviorSubject<number>(0);
  });

  it('should emit initial value', () => {
    let result: number | undefined;
    subject.subscribe(value => {
      result = value;
    });
    expect(result).toBe(0);
  });

  it('should emit new values', () => {
    let result: number | undefined;
    subject.subscribe(value => {
      result = value;
    });
    subject.next(1);
    expect(result).toBe(1);
  });

  it('should handle errors', () => {
    let error: any;
    subject.subscribe({
      error: err => {
        error = err;
      }
    });
    subject.error('Something went wrong');
    expect(error).toBe('Something went wrong');
  });

  it('should stop emitting after unsubscribe', () => {
    let result: number | undefined;
    const subscription = subject.subscribe(value => {
      result = value;
    });
    subscription.unsubscribe();
    subject.next(2);
    expect(result).toBeUndefined();
  });
});