sinon.js : 存根调用不会增加 callCount

Question

sinon.js 9.0.2

在测试中我创建了一个存根：

test.js

const myHandler = {
  handle: (some_var_to_pass) => sinon.stub()["resolves"]([{ whatever: "whatever" }]),
};

然后将测试中的实际代码作为一些端点请求（使用 async / await）执行以下代码：

code.js

module.exports = (myHandler) => ({
  getStuff: async (req, res, next) => {
  const var1 = "something1";
  const var2 = "something2";
  const my_response = await myHandler.handle()(var1, var2);

  console.log("my response", JSON.stringify(my_response)); //correct, returns { whatever: "whatever"}
  console.log("Executed stub: ", myHandler.handle(some_var_to_pass).callCount); //always returns zero

我控制 myHandler.handle 正确地完成存根创建并且 my_response 是

{ whatever: "whatever"}

但是，myHandler.handle().callCount 仍为零（而不是 undefined）。我缺少什么才能使其正确增加？或者我需要在创建存根时实际将 .callCount return 设置为 1（会很奇怪）？

Answer 1

您没有存根 myHandler.handle 方法。您只存根 myHandler.handle 方法返回的函数。单元测试方案：

code.js:

module.exports = (myHandler) => ({
  getStuff: async (req, res, next) => {
    const var1 = 'something1';
    const var2 = 'something2';
    const my_response = await myHandler.handle()(var1, var2);
    return my_response;
  },
});

code.test.js:

const code = require('./code');
const sinon = require('sinon');

describe('64468517', () => {
  it('should pass', async () => {
    const returnedFn = sinon.stub().resolves([{ whatever: 'whatever' }]);
    const myHandler = {
      handle: sinon.stub().returns(returnedFn),
    };
    await code(myHandler).getStuff();
    expect(myHandler.handle.callCount).to.be.eq(1);
    sinon.assert.calledOnce(myHandler.handle);
    sinon.assert.calledWithExactly(returnedFn, 'something1', 'something2');
  });
});

单元测试结果：

  64468517
    ✓ should pass


  1 passing (13ms)

----------|---------|----------|---------|---------|-------------------
File      | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s 
----------|---------|----------|---------|---------|-------------------
All files |     100 |      100 |     100 |     100 |                   
 code.js  |     100 |      100 |     100 |     100 |                   
----------|---------|----------|---------|---------|-------------------

Answer 2

因为当你有行：myHandler.handle(some_var_to_pass)，你启动了新的存根，它当然有 0 个 callCount。

如何解决：将myHandler.handle(some_var_to_pass)保存到一个变量，调用并期望使用该变量。

示例：

const { expect } = require('chai');
const sinon = require('sinon');

const myHandler = {
  // Call myHandler.handle() will return sinon.stub which resolves to array object.
  handle: () => sinon.stub()['resolves']([{ whatever: 'whatever' }]),
};

describe('myHandler', function() {
  it('handle', async function() {
    const var1 = 'something1';
    const var2 = 'something2';
    // Get the stub variable.
    const stub = myHandler.handle();
    // const result = await myHandler.handle()(var1, var2);
    // You use stub variable.
    const result = await stub(var1, var2);
    // Make sure the result is correct.
    expect(result).to.deep.equal([{ whatever: 'whatever' }]);
    // Obviously, stub callCount should be 1.
    expect(stub.callCount).to.equal(1);
  });
});

当我运行它在终端使用 mocha 时：

$ npx mocha index.test.js 


  myHandler
    ✓ handle


  1 passing (3ms)

sinon.js : 存根调用不会增加 callCount

sinon.js : stub call does not increment callCount

javascript

testing

stub

async-await

sinon