如何解决“不能在模块外使用导入语句"开玩笑 [英] How to resolve "Cannot use import statement outside a module" in jest

问题描述

我有一个使用 TypeScript、Jest、Webpack 和 Babel 构建的 React 应用程序(不使用 Create React App).尝试运行 yarn jest 时，出现以下错误:

I have a React application (not using Create React App) built using TypeScript, Jest, Webpack, and Babel. When trying to run yarn jest, I get the following error:

我已尝试删除所有软件包并重新添加它们.它没有解决这个问题.我看过类似的问题和文档，但我仍然误解了一些东西.我什至按照另一个指南从头开始设置此环境，但我的代码仍然收到此问题.

I have tried removing all packages and re-adding them. It does not resolve this. I have looked at similar questions and documentation and I am still misunderstanding something. I went so far as to follow another guide for setting up this environment from scratch and still received this issue with my code.

依赖项包括...

"dependencies": {
  "@babel/plugin-transform-runtime": "^7.6.2",
  "@babel/polyfill": "^7.6.0",
  "babel-jest": "^24.9.0",
  "react": "^16.8.6",
  "react-dom": "^16.8.6",
  "react-test-renderer": "^16.11.0",
  "source-map-loader": "^0.2.4"
},
"devDependencies": {
  "@babel/core": "^7.6.0",
  "@babel/preset-env": "^7.6.0",
  "@babel/preset-react": "^7.0.0",
  "@types/enzyme": "^3.9.2",
  "@types/enzyme-adapter-react-16": "^1.0.5",
  "@types/jest": "^24.0.13",

组件的导入行...

import * as React from "react";
import { BrowserRouter as Router, Route, Switch } from "react-router-dom";
import HomePage from "./components/pages";
import {
  Footer,
  Header,
  Navigation,
} from "./components/shared";

测试文件....

import * as React from "react";
import * as renderer from "react-test-renderer";
import App from "../App";

it("Renders the Footer correctly", () => {
  const tree = renderer
    .create(<App />)
    .toJSON();
  expect(tree).toMatchSnapshot();
});

我希望能够在我的组件中使用命名导入，而不会导致我的测试失败.如果我只通过我的解决方案使用默认导入似乎可以解决这个问题，但我不想走那条路.

I expected to be able to use named imports in my components without my tests blowing up. It appears to fix the issue if I only use default imports through my solution, but I would prefer to not go that route.

推荐答案

也使用 Babel、Typescript 和 Jest.有同样的失败，让我疯狂几个小时.最终为测试创建了一个新的 babel.config.js 文件.有一个很大的 .babelrc ，无论我对它做什么，它都不会被笑话所吸引.主应用程序仍然使用 .babelrc，因为它覆盖了 babel.config.js 文件.

Also using Babel, Typescript and Jest. Had the same failure, driving me crazy for hours. Ended up creating a new babel.config.js file specifically for the tests. Had a large .babelrc that wasn't getting picked up by jest no matter what i did to it. Main app still uses the .babelrc as this overrides babel.config.js files.

安装 jest、ts-jest 和 babel-jest:

Install jest, ts-jest and babel-jest:

npm i jest ts-jest babel-jest

babel.config.js(仅供 jest 使用)

babel.config.js (only used by jest)

module.exports = {presets: ['@babel/preset-env']}

jest.config.js

module.exports = {
  preset: 'ts-jest',
  transform: {
    '^.+\.(ts|tsx)?$': 'ts-jest',
    "^.+\.(js|jsx)$": "babel-jest",
  }
};

package.json

  "scripts": {
    "test": "jest"

这篇关于如何解决“不能在模块外使用导入语句"开玩笑的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！