scripts/config/env.js
'use strict'
const fs = require('fs')
const path = require('path')
const paths = require('./paths')
// Make sure that including paths.js after env.js will read .env variables.
delete require.cache[require.resolve('./paths')]
const NODE_ENV = process.env.NODE_ENV
if (!NODE_ENV) {
throw new Error(
'The NODE_ENV environment variable is required but was not specified.',
)
}
// https://github.com/bkeepers/dotenv#what-other-env-files-can-i-use
let dotenvFiles = [
`${paths.dotenv}.${NODE_ENV}.local`,
`${paths.dotenv}.${NODE_ENV}`,
// Don't include `.env.local` for `test` environment
// since normally you expect tests to produce the same
// results for everyone
NODE_ENV !== 'test' && `${paths.dotenv}.local`,
paths.dotenv,
].filter(Boolean)
// Load environment variables from .env* files. Suppress warnings using silent
// if this file is missing. dotenv will never modify any environment variables
// that have already been set. Variable expansion is supported in .env files.
// https://github.com/motdotla/dotenv
// https://github.com/motdotla/dotenv-expand
dotenvFiles.forEach((dotenvFile) => {
if (fs.existsSync(dotenvFile)) {
require('dotenv-expand')(
require('dotenv').config({
path: dotenvFile,
}),
)
}
})
// We support resolving modules according to `NODE_PATH`.
// This lets you use absolute paths in imports inside large monorepos:
// https://github.com/facebook/create-react-app/issues/253.
// It works similar to `NODE_PATH` in Node itself:
// https://nodejs.org/api/modules.html#modules_loading_from_the_global_folders
// Note that unlike in Node, only *relative* paths from `NODE_PATH` are honored.
// Otherwise, we risk importing Node.js core modules into an app instead of Webpack shims.
// https://github.com/facebook/create-react-app/issues/1023#issuecomment-265344421
// We also resolve them to make sure all tools using them work consistently.
const appDirectory = fs.realpathSync(process.cwd())
process.env.NODE_PATH = (process.env.NODE_PATH || '')
.split(path.delimiter)
.filter((folder) => folder && !path.isAbsolute(folder))
.map((folder) => path.resolve(appDirectory, folder))
.join(path.delimiter)
// Grab NODE_ENV and REACT_APP_* environment variables and prepare them to be
// injected into the application via DefinePlugin in Webpack configuration.
const REACT_APP = /^REACT_APP_/i
function getClientEnvironment(publicUrl) {
const raw = Object.keys(process.env)
.filter((key) => REACT_APP.test(key))
.reduce(
(env, key) => {
env[key] = process.env[key]
return env
},
{
// Useful for determining whether we’re running in production mode.
// Most importantly, it switches React into the correct mode.
NODE_ENV: process.env.NODE_ENV || 'development',
// Useful for resolving the correct path to static assets in `public`.
// For example, <img src={process.env.PUBLIC_URL + '/img/logo.png'} />.
// This should only be used as an escape hatch. Normally you would put
// images into the `src` and `import` them in code to get their paths.
PUBLIC_URL: publicUrl,
},
)
// Stringify all values so we can feed into Webpack DefinePlugin
const stringified = {
'process.env': Object.keys(raw).reduce((env, key) => {
env[key] = JSON.stringify(raw[key])
return env
}, {}),
}
return { raw, stringified }
}
module.exports = getClientEnvironment