Question

考虑以下mocha + chai + sinon测试：

it("will invoke the 'then' callback if the executor calls its first argument", function(done){
    let executor = function(resolve, reject){
        resolve();
    }
    let p = new Promise(executor);
    let spy = sinon.spy();

    p.then(spy);

    spy.should.have.been.called.notify(done);
});

如断言中所述，我预计应该调用间谍。但是，摩卡报道：

1) A Promise
   will invoke the 'then' callback if the executor calls its first argument:
    AssertionError: expected spy to have been called at least once, but it was never called

用console.log代替间谍演示了预期的流量，所以我很困惑为什么摩卡会报告负面。

如何更改测试以证明预期的行为？

Answer 1

我发现解决方案是使用async / await，如下所示：

it("will invoke the 'then' callback if the executor calls its first argument", async() => {
    let executor = function(resolve, reject){
        resolve();
    }
    let p = new Promise(executor);
    let spy = sinon.spy();

    await p.then(spy);

    spy.should.have.been.called;
});

Answer 2

实现同样目标的另一种方法是：

it("will invoke the 'then' callback if the executor calls its first argument", function(){
    let p = new Promise(function(resolve, reject){ resolve(); });
    let resolver = sinon.spy();

    p.then(resolver);

    return p.then( () => { resolver.should.have.been.called; });
});

如何使用mocha，chai和sinon证明调用执行回调？

2 个答案: