Vite / Jest / React-Testing

Question

我正在尝试使用Jest在React应用程序中进行测试；我的应用程序使用Vite作为模块绑定器。问题是，每次我运行测试时，我都会收到以下错误：

> react-test@0.0.0 test
> jest
FAIL  src/test/App.test.jsx
● Test suite failed to run
Jest encountered an unexpected token
Jest failed to parse a file. This happens e.g. when your code or its dependencies use non-standard JavaScript syntax, or when Jest is not configured to support such syntax.
Out of the box Jest supports Babel, which will be used to transform your files into valid JS based on your Babel configuration.
By default "node_modules" folder is ignored by transformers.
Here's what you can do:
• If you are trying to use ECMAScript Modules, see https://jestjs.io/docs/ecmascript-modules for how to 
enable it.
• If you are trying to use TypeScript, see https://jestjs.io/docs/getting-started#using-typescript      
• To have some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config.
• If you need a custom transformation specify a "transform" option in your config.
• If you simply want to mock your non-JS modules (e.g. binary assets) you can stub them out with the "moduleNameMapper" config option.
You'll find more details and examples of these config options in the docs:
https://jestjs.io/docs/configuration
For information about custom transformations, see:
https://jestjs.io/docs/code-transformation
Details:
SyntaxError: C:UsersTomasDesktopreact-testsrctestApp.test.jsx: Support for the experimental syntax 'jsx' isn't currently enabled (8:30):
6 |
7 | test("renders content", ()=>{
>  8 |     const component = render(<App></App>)
|                              ^
9 |     console.log(component)
10 | })
Add @babel/preset-react (https://git.io/JfeDR) to the 'presets' section of your Babel config to enable transformation.
If you want to leave it as-is, add @babel/plugin-syntax-jsx (https://git.io/vb4yA) to the 'plugins' section to enable parsing.
at Parser._raise (node_modules/@babel/parser/src/parser/error.js:150:45)
at Parser.raiseWithData (node_modules/@babel/parser/src/parser/error.js:145:17)
at Parser.expectOnePlugin (node_modules/@babel/parser/src/parser/util.js:214:18)
at Parser.parseExprAtom (node_modules/@babel/parser/src/parser/expression.js:1238:16)
at Parser.parseExprSubscripts (node_modules/@babel/parser/src/parser/expression.js:682:23)
at Parser.parseUpdate (node_modules/@babel/parser/src/parser/expression.js:662:21)
at Parser.parseMaybeUnary (node_modules/@babel/parser/src/parser/expression.js:633:23)
at Parser.parseMaybeUnaryOrPrivate (node_modules/@babel/parser/src/parser/expression.js:388:14)        
at Parser.parseExprOps (node_modules/@babel/parser/src/parser/expression.js:398:23)
at Parser.parseMaybeConditional (node_modules/@babel/parser/src/parser/expression.js:356:23)
Test Suites: 1 failed, 1 total
Tests:       0 total
Snapshots:   0 total
Time:        1.379 s
Ran all test suites.

包.json

{
"name": "react-test",
"private": true,
"version": "0.0.0",
"type": "module",
"scripts": {
"dev": "vite",
"build": "vite build",
"preview": "vite preview",
"test": "jest"
},
"dependencies": {
"react": "^17.0.2",
"react-dom": "^17.0.2"
},
"jest": {
"verbose": true,
"testEnvironment": "jsdom",
"transform": {
"^.+\.(js|jsx)$": "babel-jest"
},
"moduleFileExtensions": [
"js",
"jsx"
],
"moduleNameMapper": {
"\.(gif|ttf|eot|svg|png)$": "<rootDir>/test/__mocks__/fileMock.js",
"\.(css|less|sass|scss)$": "identity-obj-proxy"
}
},
"devDependencies": {
"@babel/plugin-syntax-jsx": "^7.16.7",
"@testing-library/jest-dom": "^5.16.2",
"@testing-library/react": "^12.1.3",
"@types/jest": "^27.4.1",
"@vitejs/plugin-react": "^1.0.7",
"jest": "^27.5.1",
"vite": "^2.8.0"
}
}

App.test.jsx

import React from "react";
import "@testing-library/jest-dom/extend-expect"
import { render } from "@testing-library/react";
import App from "../App.jsx";

test("renders content", ()=>{
const component = render(<App></App>)
console.log(component)
})

Answer 1

错误输出是正确的，Jest在本地节点二进制文件上运行，并要求将jsx文件转换为它可以理解的语法。

Vite在默认情况下不会进行此转换。它的设计目的是将您的代码转换并捆绑到一些适合浏览器的bundle.js中(它可以执行其他类型的输出，如库。您需要调整vite.config.js(。

幸运的是，其他人已经为你解决了这个问题。我建议使用vitest，因为您不需要下载另一个转换器，也不需要花费大量时间来设置棘手的构建脚本。

以下是如何快速设置的指南：

https://www.eternaldev.com/blog/testing-a-react-application-with-vitest/

以及迁移指南：

https://vitest.dev/guide/migration.html