Next.js jest-fetch-模拟给出了TextDecoder的错误

Question

对于我的Next.JS，我有以下设置

jest.config.js

/* eslint-disable @typescript-eslint/no-var-requires */
// jest.config.js
const nextJest = require('next/jest')

const createJestConfig = nextJest({
  // Provide the path to your Next.js app to load next.config.js and .env files in your test environment
  dir: './'
})

// Add any custom config to be passed to Jest
const customJestConfig = {
  // Add more setup options before each test is run
  setupFilesAfterEnv: ['<rootDir>/jest.setup.ts'],
  // if using TypeScript with a baseUrl set to the root directory then you need the below for alias' to work
  moduleDirectories: ['<rootDir>/node_modules', '<rootDir>/src', '<rootDir>/pages'],
  testEnvironment: 'jest-environment-jsdom',
  testPathIgnorePatterns: [
    '<rootDir>/.next/',
    '<rootDir>/node_modules/',
    '<rootDir>/coverage',
    '<rootDir>/dist'
  ],
  moduleNameMapper: {
    '^@/(.*)$': '<rootDir>/$1'
  },
  resolver: '<rootDir>/.jest/resolver.js'
}

// createJestConfig is exported this way to ensure that next/jest can load the Next.js config which is async
module.exports = createJestConfig(customJestConfig)

jest.setup.ts

import '@testing-library/jest-dom'
import '@testing-library/jest-dom/extend-expect'
import fetchMock from 'jest-fetch-mock'

jest.mock('next/config', () => () => ({
  publicRuntimeConfig: {}
}))

fetchMock.enableMocks()

但是，我一直收到错误"ReferenceError: TextEncoder未定义“。有人能帮忙吗？

​

​

请注意

• 我需要使用jest-environment-jsdom作为testEnvironment，因为我有react组件，我也在测试

此外，如许多条款所述，添加以下内容不起作用：

import { TextEncoder, TextDecoder } from 'util'
global.TextEncoder = TextEncoder
global.TextDecoder = TextDecoder

Answer 1

关键是使用require而不是import。在启用fetch模拟之前，必须先设置全局变量。

//jest.setup.ts

import '@testing-library/jest-dom'
import '@testing-library/jest-dom/extend-expect'
import { TextDecoder, TextEncoder } from 'util'
global.TextEncoder = TextEncoder
global.TextDecoder = TextDecoder

require('jest-fetch-mock').enableMocks()

jest.mock('next/config', () => () => ({
  publicRuntimeConfig: {}
}))