React Native: process.env has only NODE_ENV

Question

I'm setting an environment variable while building my react-native app (on windows):

SET APP_ENV=dev & react-native run-android

echo %APP_ENV% returns 'dev'

But when I log process.env object in my JS file, I only get:

{
  NODE_ENV: "development"
}

Is there a different way to access environment variables set through command prompt?

Answer 1

It's important to know that the React-Native app is running on a device (or emulator) in an environment more like a browser, not a Node.js process.

For cross-compatibility with Node.js libraries that relies on process.env.NODE_ENV to perform optimizations, React-Native adds the process global variable with env.NODE_ENV.

If you want to pass custom constants to React-Native, you can use: https://github.com/luggit/react-native-config

Answer 2

You should install this plugin babel plugin

npm install babel-plugin-transform-inline-environment-variables --save-dev

Then add it to your babel config (.babelrc, babel.config.js) in the plugin section

{
  "plugins": [
    ["transform-inline-environment-variables", {
      "include": [
        "NODE_ENV"
      ]
    }]
  ]
}

Then when you pass the variable through the inline like

API_KEY=dev && react-native run-android

You should get it through

process.env.API_KEY

And the value will be dev

This work for me on Mac terminal, Hope it answer your question

EDIT: I added a double "&" because only one doesn't work.