javascript - Jasmine:如何监视内部对象方法调用？

Question

我有两个原型(prototype)要测试:

var Person = function() {};

Person.prototype.pingChild = function(){
   var boy = new Child();
   boy.getAge();
}

var Child = function() {};

Child.prototype.getAge = function() {
    return 42;
};

我到底想测试什么:检查 getAge() 方法是否在 pingChild() 方法内部被调用

这是我尝试用于此目的的 Jasmine 规范:

describe("Person", function() {
    it("calls the getAge() function", function() {
        var fakePerson = new Person();
        var chi = new Child();
        spyOn(fakePerson, "getAge");
        fakePerson.pingChild();
        expect(chi.getAge).toHaveBeenCalled();
    });
});

describe("Person", function() {
    it("calls the getAge() function", function() {
        var fakePerson = new Person();
        spyOn(fakePerson, "getAge");
        fakePerson.pingChild();
        expect(fakePerson.getAge).toHaveBeenCalled();
    });
});

describe("Person", function() {
    it("calls the getAge() function", function() {
        var fakePerson = new Person();
        var chi = new Child();
        spyOn(chi, "getAge");
        fakePerson.pingChild();
        expect(chi.getAge).toHaveBeenCalled();
    });
});

但它们都只显示错误:

• getAge() method does not exist
• getAge() method does not exist
• Expected spy getAge to have been called

那么，是否有任何方法可以使用 Jasmine 测试此类情况，如果是的话 - 如何完成？

Answer 1

你已经监视了 Child 对象的原型(prototype)。

describe("Person", function () {
  it("calls the getAge() function", function () {
    var spy = spyOn(Child.prototype, "getAge");
    var fakePerson = new Person();
    fakePerson.pingChild();
    expect(spy).toHaveBeenCalled();
  });
});