in config/env.js [26:45]
function getClientEnvironment(publicUrl) {
return Object
.keys(process.env)
.filter(key => REACT_APP.test(key))
.reduce((env, key) => {
env['process.env.' + key] = JSON.stringify(process.env[key]);
return env;
}, {
// Useful for determining whether we’re running in production mode.
// Most importantly, it switches React into the correct mode.
'process.env.NODE_ENV': JSON.stringify(
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.
'process.env.PUBLIC_URL': JSON.stringify(publicUrl)
});
}