Question

Jest没有提供我的手动模拟。一切似乎都在正确的目录中。我错过了什么？

的src /适配器/ __嘲笑__ / Foo.js

const spy = jest.genMockFromModule('../Foo')

function doStuff() {
  return { source: 'mock' }
}

spy.doStuff = doStuff
module.exports = spy

的src /适配器/ Foo.js

class Foo {
  doStuff() {
    return { source: 'real' }
  }
}

module.exports = Foo

的src /适配器/ __测试__ / Foo.js

const Foo = require('../Foo')

test('Foo', () => {
  const foo = new Foo()
  expect(foo.doStuff()).toEqual({ source: 'mock' })
})

测试输出：

expect(received).toEqual(expected)

    Expected value to equal:
      {"source": "mock"}
    Received:
      {"source": "real"}

    Difference:

    - Expected
    + Received

      Object {
    -   "source": "mock",
    +   "source": "real",
      }

      3 | test('Foo', () => {
      4 |   const foo = new Foo()
    > 5 |   expect(foo.doStuff()).toEqual({ source: 'mock' })
      6 | })
      7 |

      at Object.<anonymous>.test (adapters/__tests__/Foo.js:5:25)

Jest Version：“jest-cli”：“^ 23.0.0-alpha.0”

远射，试过这个，但没有奏效。没有找到模拟，只是在调用doStuff（）

时给了我未定义的内容

的src /适配器/ __测试__ / Foo.js

//TREID this but didn't work
jest.mock('../Foo')

const Foo = require('../Foo')

test('Foo', () => {
  const foo = new Foo()
  expect(foo.doStuff()).toEqual({ source: 'mock' })
})

Answer 1

尝试使用下面的代码，问题是我们模拟ES6类的方式，基本上，有4种方法来模拟class，如文档中所述

https://facebook.github.io/jest/docs/en/es6-class-mocks.html

<强>的src /适配器/ __嘲笑__ / Foo.js

const mock = jest.fn().mockImplementation(()=>{
   return {
       doStuff: jest.fn(()=>({source: 'mock'}))
   } 
});

module.exports = mock;

<强>的src /适配器/ __测试__ / Foo.js

jest.mock('../Foo');

const Foo = require('../Foo');

test('Foo', () => {
    const foo = new Foo();
    expect(foo.doStuff()).toEqual({ source: 'mock' })
});

<强>（或）

内联模拟也可以使用

<强>的src /适配器/ __测试__ / Foo.js

jest.mock('../Foo', () => {
    return jest.fn().mockImplementation(() => {
        return {
            doStuff: jest.fn(() => ({ source: 'mock' }))
        }
    });
});


const Foo = require('../Foo');

test('Foo', () => {
    const foo = new Foo();
    expect(foo.doStuff()).toEqual({ source: 'mock' })
});

Answer 2

您是否尝试将__mocks__（或您的模拟现场）目录添加到roots中的package.json？

"jest": {
  "roots": [
    "<rootDir>/__mocks__",
    "<rootDir>/src"
  ],
...

手动模拟没有被拿起

2 个答案: