如何使用jasmine为注销服务正确编写单元测试？

describe('Logout Service', function() {
  it('should successfully logout user', function() {
    // 模拟用户对象和注销服务
    var user = { id: 1, name: 'John' };
    var logoutService = new LogoutService();

    // 调用注销服务
    var result = logoutService.logout(user);

    // 验证结果是否符合预期
    expect(result).toEqual('User logged out successfully');
  });

  it('should handle logout failure', function() {
    // 模拟用户对象和注销服务
    var user = { id: 1, name: 'John' };
    var logoutService = new LogoutService();

    // 调用注销服务，模拟注销失败的情况
    spyOn(logoutService, 'logout').and.returnValue(false);
    var result = logoutService.logout(user);

    // 验证结果是否符合预期
    expect(result).toEqual('Logout failed');
  });
});