如何从 package.json 设置 NODE_ENV 以进行反应

Question

I am trying to target multiple environments from local while executing React app.

1. Development
2. Staging
3. Production

I am also trying to test for offline mode in any of the environments. So, the scripts what I have configured is as follows:

    "staging-server": "nodemon server.js --environment=staging",
    "staging": "concurrently -k  \"npm:staging-server\" \"NODE_ENV='staging' PORT=3003 react-scripts start\"",
    "prod": "npm run build && forever server.js --environment=production"

I am able to fetch environment arg using args inside my Express, but my local ui app is still showing development only when I console for process.env.NODE_ENV. I am also trying to set NODE_ENV with same line for staging, but still no luck. PORT setting is working but, the app is running in 3000 and 3003 both ports.

How to get rid of this? I would like to understand the staging configuration as well.

Answer 1

As per the docs, we cannot override NODE_ENV, but there is a room to create our own custom variables starting with REACT_APP_. So i configured to look as below:

Reference: https://facebook.github.io/create-react-app/docs/adding-custom-environment-variables

"staging": "concurrently -k  \"npm:staging-server\" \"cross-env REACT_APP_ENVIRONMENT='staging' PORT=3003 react-scripts start\"",

And inside my UI application, I can fetch its value by consoling it like this: console.log('REACT_APP_ENVIRONMENT => ', process.env.REACT_APP_ENVIRONMENT);

Answer 2

I build the build with REACT_APP_STAGE and use it in my application as process.env.REACT_APP_STAGE.

"scripts": {
    "analyze": "source-map-explorer 'build/static/js/*.js'",
    "build-css": "node-sass-chokidar --include-path ./src --include-path ./node_modules src/ -o src/",
    "watch-css": "npm run build-css && node-sass-chokidar --include-path ./src --include-path ./node_modules src/ -o src/ --watch --recursive",
    "start-js": "react-scripts start",
    "start": "REACT_APP_STAGE=local npm-run-all -p watch-css start-js",
    "build": "npm run build-css && react-scripts build",
    "build-dev": "REACT_APP_STAGE=dev react-scripts build",
    "build-prod": "REACT_APP_STAGE=prod react-scripts build",
    "build-qa": "REACT_APP_STAGE=qa react-scripts build",
    "test": "react-scripts test --env=jsdom",
    "eject": "react-scripts eject"
  },

Answer 3

在 NODE_ENV 前面使用 cross-env。

npm i -g cross-env

"staging": "concurrently -k  \"npm:staging-server\" \"cross-env NODE_ENV='staging' PORT=3003 react-scripts start\"",

Answer 4

Easiest approach is to add it directly in your command:

"scripts": {
    "start": "./node_modules/.bin/nodemon server.js",
    "start:prod": "NODE_ENV=prod node server.js",
  },