nodejs

首先react需要安装nodejs
然后安装react
https://www.runoob.com/react/react-install.html


TypeError [ERR_INVALID_ARG_TYPE]: The "path" argument must be of type string. Received undefined
    at validateString (internal/validators.js:117:11)
    at Object.join (path.js:375:7)
    at noopServiceWorkerMiddleware (D:IDEAworkxlore-util
ode_modules
eact-dev-utils
oopServiceWorkerMiddleware.js:14:26)
    at Layer.handle [as handle_request] (D:IDEAworkxlore-util
ode_modulesexpresslib
outerlayer.js:95:5)
    at trim_prefix (D:IDEAworkxlore-util
ode_modulesexpresslib
outerindex.js:317:13)
    at D:IDEAworkxlore-util
ode_modulesexpresslib
outerindex.js:284:7
    at Function.process_params (D:IDEAworkxlore-util
ode_modulesexpresslib
outerindex.js:335:12)
    at next (D:IDEAworkxlore-util
ode_modulesexpresslib
outerindex.js:275:10)
    at launchEditorMiddleware (D:IDEAworkxlore-util
ode_modules
eact-dev-utilserrorOverlayMiddleware.js:20:7)
    at Layer.handle [as handle_request] (D:IDEAworkxlore-util
ode_modulesexpresslib
outerlayer.js:95:5)
    at trim_prefix (D:IDEAworkxlore-util
ode_modulesexpresslib
outerindex.js:317:13)
    at D:IDEAworkxlore-util
ode_modulesexpresslib
outerindex.js:284:7
    at Function.process_params (D:IDEAworkxlore-util
ode_modulesexpresslib
outerindex.js:335:12)
    at next (D:IDEAworkxlore-util
ode_modulesexpresslib
outerindex.js:275:10)
    at handleWebpackInternalMiddleware (D:IDEAworkxlore-util
ode_modules
eact-dev-utilsevalSourceMapMiddleware.js:42:7)
    at Layer.handle [as handle_request] (D:IDEAworkxlore-util
ode_modulesexpresslib
outerlayer.js:95:5)

一般是因为版本问题。
我这边的解决办法：

1. 在package.json中，把"react-scripts": "^3.3.0" 替换为"react-scripts": "^3.4.0"
2. 删除node_modules文件夹
3. 执行npm install 或者 yarn install重新安装依赖包（在工程所在文件夹shift + 右键  - 在此处打开命令窗口，然后输入，  或者直接cmd然后cd到所在位置也行）

然后

yarn start
启动