.env-cmdrc

{
    "development": {
        "PORT": 3000,
        "BROWSER": "none",
        "REACT_APP_MODE": "development"
    },
    "build-dev": {
        "GENERATE_SOURCEMAP": true,
        "REACT_APP_MODE": "development"
    },
    "build-prod": {
        "GENERATE_SOURCEMAP": false,
        "REACT_APP_MODE": "production"
    }
}