jest mock 返回 undefined

V2EX = way to explore

V2EX 是一个关于分享和探索的地方

现在注册

已注册用户请登录

推荐关注

Meteor

JSLint - a Javascript code quality tool

jsFiddle

D3.js

WebStorm

推荐书目

Javascript 权威指南第 5 版

Closure: The Definitive Guide

这是一个创建于 1764 天前的主题，其中的信息可能已经有所发展或是发生改变。

client.js

module.exports = class ProductsClient { async getById(id) { const url = `http://localhost:3000/api/products/{id}`; const respOnse= await fetch(url); return await response.json(); } }

manager.js

const ProductsClient = require('./client'); module.exports = class ProductManager { async getProductToManage(id) { const productsClient = new ProductsClient(); const productToManage = await productsClient.getById(id) .catch(err => alert(err)); return productToManage; } }

test.js

const ProductsClient = require('./client'); const ProductManager = require('./manager'); jest.mock('./client'); describe('test', () => { test('111', async () => { const expectedProduct = { id: 1, name: 'football', }; const mockGetById = jest.fn(); mockGetById.mockResolvedValue(expectedProduct); ProductsClient.prototype.getById = mockGetById; const productManager = new ProductManager(); const result = await productManager.getProductToManage(1); expect(result.name).toBe('football'); }) })

在 test.js 中 mock client 完全没问题。一旦把const productsClient = new ProductsClient();拿到class ProductManager外，getById就返回 undefined

const ProductsClient = require('./client'); const productsClient = new ProductsClient(); module.exports = class ProductManager { async getProductToManage(id) { const productToManage = await productsClient.getById(id) // undefined .catch(err => alert(err)); return productToManage; } }

jest mock module 文档里也没找到类似的例子。

4 条回复 2021-02-18 10:03:23 +08:00