Environment variable expansion not longer works in npm run on Windows

If environment variable expansion is no longer working in npm run commands on Windows, it might be due to changes in the Node.js or npm configuration. Here are a few troubleshooting steps to resolve the issue:

1. Update Node.js and npm: Ensure that you have the latest versions of Node.js and npm installed on your system. Visit the official Node.js website (https://nodejs.org) and download the latest stable version.

2. Check your npm scripts: Review the scripts section in your package.json file to verify that environment variables are used correctly. Make sure you're using the correct syntax for environment variable expansion. For example:

   jsonCopy code
   {
   
     "scripts": {
   
       "start": "NODE_ENV=development node server.js",
   
       "build": "cross-env NODE_ENV=production webpack --config webpack.config.js"
   
     }
   
   }
   
   

   In this example, the NODE_ENV environment variable is being set for different commands.

3. Cross-platform compatibility: Keep in mind that Windows and Unix-like systems have different conventions for environment variable expansion. Use cross-platform tools like cross-env (https://www.npmjs.com/package/cross-env) to set environment variables in a consistent manner across different operating systems.

   Install cross-env as a development dependency:

   shellCopy code
   npm install --save-dev cross-env
   
   

   Modify your npm scripts to use cross-env:

   jsonCopy code
   {
   
     "scripts": {
   
       "start": "cross-env NODE_ENV=development node server.js",
   
       "build": "cross-env NODE_ENV=production webpack --config webpack.config.js"
   
     }
   
   }
   
   

   This ensures that environment variables are set correctly, regardless of the operating system.

4. Verify environment variable values: Check if the environment variables you're trying to expand are set correctly on your Windows system. You can do this by running echo %VARIABLE_NAME% in the command prompt to verify the values.

   For example, to check the value of the NODE_ENV variable:

   shellCopy code
   echo %NODE_ENV%
   
   

   If the value is not displayed, it means the variable is not set, and you may need to set it explicitly.

By following these steps, you should be able to resolve the issue with environment variable expansion in npm run commands on Windows.