npm 测试时如何解决"cannot find module"

Question

我正在使用create-react应用程序。当我输入‘npm测试’时，出现一个错误"；找不到模块"；。我想jest已经安装在create-rect应用程序中了。下面是我的包.json。有什么想法吗？

{
"proxy": "http://localhost:5000",
"name": "276_project",
"version": "0.1.0",
"private": true,
"dependencies": {
"@testing-library/jest-dom": "^4.2.4",
"@testing-library/react": "^9.5.0",
"@testing-library/user-event": "^7.2.1",
"axios": "^0.19.2",
"bulma": "^0.9.0",
"jwt-decode": "^2.2.0",
"node-sass": "^4.14.1",
"react": "^16.13.1",
"react-bootstrap": "^1.2.2",
"react-cart-components": "^2.1.0",
"react-dom": "^16.13.1",
"react-hook-form": "^5.7.2",
"react-router-dom": "^5.2.0",
"react-scripts": "3.4.1",
"react-stripe-checkout": "^2.6.3",
"react-toastify": "^6.0.6",
"serve": "^11.3.2"
},
"scripts": {
"start": "react-scripts start",
"build": "react-scripts build",
"test": "react-scripts test",
"eject": "react-scripts eject",
"heroku-postbuild": "npm run build"
},
"eslintConfig": {
"extends": "react-app"
},
"browserslist": {
"production": [
">0.2%",
"not dead",
"not op_mini all"
],
"development": [
"last 1 chrome version",
"last 1 firefox version",
"last 1 safari version"
]
}
}

Answer 1

我正在使用我自己的入门包，但我想问题是一样的。只是开玩笑，看不到我们包含的模块。首先安装yarn add identity-obj-proxy -D或npm install identity-obj-proxy -D&quot-D"；这里的标志是为我的操作系统Ubuntu 20.04，为其他操作系统应该使用"--保存dev"；旗帜或类似的东西。那么，你应该在"；创建react应用程序"；是你的"；js"并且部分地"；moduleNameMapper"；设置如下矿井配置。适用于打字稿&amp；javascript。

module.exports = {
preset: 'ts-jest',
roots: ['<rootDir>/src'],
moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json', 'node'],
transform: {
'\.(ts|tsx)$': 'ts-jest',
},
setupFiles: ['raf/polyfill'],
testRegex: '/__tests__/.*\.(ts|tsx|js)$',
moduleNameMapper: {
'^.+\.(s?css|less|jpg|png|svg)$': 'identity-obj-proxy',
},
setupFilesAfterEnv: ['<rootDir>/src/setupTests.ts'],
snapshotSerializers: [],
};