功能上的sinon间谍无法正常工作

本文介绍了功能上的sinon间谍无法正常工作的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我正在尝试为此简单的中间件功能编写独立测试

I'm trying to write a standalone test for this simple middleware function

function onlyInternal (req, res, next) { if (!ReqHelpers.isInternal(req)) { return res.status(HttpStatus.FORBIDDEN).send() } next() } // Expose the middleware functions module.exports = { onlyInternal }

这不起作用

describe('success', () => { let req = { get: () => {return 'x-ciitizen-token'} } let res = { status: () => { return { send: () => {} } } } function next() {} let spy before(() => { spy = sinon.spy(next) }) after(() => { sinon.restore() }) it('should call next', () => { const result = middleware.onlyInternal(req, res, next) expect(spy.called).to.be.true <-- SPY.CALLED IS ALWAYS FALSE EVEN IF I LOG IN THE NEXT FUNCTION SO I KNOW IT'S GETTING CALLED }) })

但是可以.

describe('success', () => { let req = { get: () => {return 'x-ciitizen-token'} } let res = { status: () => { return { send: () => {} } } } let next = { next: () => {} } let spy before(() => { spy = sinon.spy(next, 'next') }) after(() => { sinon.restore() }) it('should call next', () => { const result = middleware.onlyInternal(req, res, next.next) expect(spy.called).to.be.true }) })

为什么不仅仅监视功能正常工作?

Why isn't spying on just the function working?

推荐答案

Sinon无法更改现有函数的内容，因此它创建的所有间谍程序都只是对现有函数的包装，这些计数可以计数调用，记住args等.

Sinon cannot change content of existing function, so all spies it creates are just wrappers over existing function that count calls, memoize args etc.

因此，您的第一个示例与此相同:

So, your first example is equal to this:

function next() {} let spy = sinon.spy(next); next(); // assuming that middleware is just calling next // spy is not used!

您的第二个示例等于:

let next = { next: () => {} } next.next = sinon.spy(next.next); // sinon.spy(obj, 'name') just replaces obj.name with spy on it next.next(); // you actually call spy which in in turn calls original next.next //spy is called. YaY

因此，它们在sinon中间谍"和存根"的关键在于您必须在测试中使用间谍/存根功能.您的原始代码只是使用了原始的非间谍功能.

So, they key to 'spying' and 'stubbing' in sinon is that you have to use spied/stubbed function in test. Your original code just used original, non-spied function.