1. Configure environment variables with cross Env and install cross env

 npm install cross-env –save-dev 

2. Create a new file in the config file testProd.env.js The contents are as follows

'use strict'
module.exports = {
  NODE_ENV: '"testProd"',
  ENV_CONFIG: '"testProd"'
}

3. Create a new file in the config file prod.env.js The contents are as follows

 'use strict'
 module.exports = {
  NODE_ENV: '"production"',
  ENV_CONFIG: '"prod"'
}

4. Modify the configuration/ index.js file

Add the following code:

prodEnv: require('./prod.env'),
testProdEnv: require('./testProd.env')

5. Modify bulid/ webpack.prod.conf . JS file

//const env = require('../config/prod.env'); //Annotate this line
const env = config.build[process.env.env_config + 'Env'] //change to this code

6. Modify build/ build.js file

//process.env.NODE_ENV = "production";  //Annotate this line
//const spinner = ora('building for production...')  //Annotate this line and change to these codes below
var spinner = ora(
  'building for ' +
    process.env.NODE_ENV +
    ' of ' +
    process.env.env_config +
    ' mode...'
)  

7. Modification package.json And packing command

 "build": "cross-env NODE_ENV=prod env_config=prod node build/build.js",
 "build:testProd": "cross-env NODE_ENV=testProd env_config=testProd node build/build.js"