warn user when using minified code outside of NODE_ENV 'production'

src/index.js

@@ -4,6 +4,22 @@ import bindActionCreators from './utils/bindActionCreators'
 import applyMiddleware from './utils/applyMiddleware'
 import compose from './utils/compose'
 
+/*
+* create a function so that we can check if the function name has been altered by minification
+* if the function has been minified and NODE_ENV !== 'production', warn the user
+*/
+function isCrushed() {}
+
+if (isCrushed.name !== 'isCrushed' && process.env.NODE_ENV !== 'production') {
+  /*eslint-disable no-console */
+  console.error('You are currently using minified code outside of NODE_ENV === \'production\'. ' + 
+    'This means that you are running a slower development only build of Redux. ' + 
+    'Consult tools such as loose-envify (https://github.com/zertosh/loose-envify) for browserify ' + 
+    'and DefinePlugin for webpack (http://stackoverflow.com/questions/30030031) ' + 
+    'to build with proper NODE_ENV') 
+  /*eslint-enable */
+}
+
 export {
   createStore,
   combineReducers,