笑话模拟依赖生成器函数

Question

我无法模拟一个简单的依赖生成器函数。

//generatorFunction.js
export default ()=>({execute: (arg1)=>Promise.resolve(arg1)})

//actualFunction.js
import generate from 'generatorFunction'
export default (arg1)=>generate(arg1)

//actualFunction.test.js
import actualFunction from './actualFunction'
import generatorFunction from './generatorFunction'
const resultingGeneratedFunction = generatorFunction();

jest.mock('generatorFunction', ()=>jest.fn(()=>({execute: ()=>Promise.resolve()})))
it('calls generateFunction', function(done){
  actualFunction(1).then(()=>{
   expect(resultingGeneratedFunction.execute).toHaveBeenCalledOnce()
   done()
  })
})

从不调用执行时出现的错误，尽管当我在实际函数中的控制台日志中看到调用了执行。

Answer 1

问题是开玩笑不能知道你在测试中的某个地方使用了 Promise。您要么使用async/await 回报承诺。看看docs

import actualFunction from './actualFunction'
import generate from 'generatorFunction'

jest.mock('generatorFunction', ()=>jest.fn(()=>({execute: ()=>Promise.resolve()})))
it('calls generateFunction', function(){
  return actualFunction(1).then(()=>{
   expect(generateFunction.execute).toHaveBeenCalledOnce()
  })
})

import actualFunction from './actualFunction'
import generate from 'generatorFunction'

jest.mock('generatorFunction', ()=>jest.fn(()=>({execute: ()=>Promise.resolve()})))
it('calls generateFunction', async function(){
  const value = await actualFunction(1)
  expect(generateFunction.execute).toHaveBeenCalledOnce()
})