react reads env data in build

.envBy default the file will be read

 npm install dotenv --save 
 npm install dotenv-cli --save-dev

For example read.env.test

"build:test": "dotenv -e .env.test react-app-rewired build",

.env.test

REACT_APP_CURRENTMODE = 'dev'

REACT_APP_Public_Path = "https://baidu.com/demo"

The test packaged file is correct