Install gem react-rails-hot-loader

Gemfile

@@ -20,6 +20,7 @@ gem 'simple_form'
 gem 'upmin-admin'
 gem 'dotenv-rails'
 gem 'react-rails'
+gem 'react-rails-hot-loader'
 group :development do
   gem 'better_errors'
   gem 'rubocop', require: false

Gemfile.lock

@@ -108,7 +108,11 @@ GEM
     dotenv-rails (2.0.2)
       dotenv (= 2.0.2)
       railties (~> 4.0)
+    em-websocket (0.5.1)
+      eventmachine (>= 0.12.9)
+      http_parser.rb (~> 0.6.0)
     erubis (2.7.0)
+    eventmachine (1.0.8)
     execjs (2.6.0)
     factory_girl (4.5.0)
       activesupport (>= 3.0.0)
@@ -162,6 +166,7 @@ GEM
       haml (~> 4.0.0)
       nokogiri (~> 1.6.0)
       ruby_parser (~> 3.5)
+    http_parser.rb (0.6.0)
     hub (1.12.4)
     i18n (0.7.0)
     interception (0.5)
@@ -264,6 +269,10 @@ GEM
       execjs
       rails (>= 3.2)
       tilt
+    react-rails-hot-loader (0.4.0)
+      em-websocket
+      rails
+      react-rails
     responders (1.1.2)
       railties (>= 3.2, < 4.2)
     rspec (3.3.0)
@@ -408,6 +417,7 @@ DEPENDENCIES
   rb-fsevent
   rb-inotify
   react-rails
+  react-rails-hot-loader
   rspec-rails
   rubocop
   sass-rails (~> 4.0.3)

app/assets/javascripts/application.js

@@ -16,4 +16,5 @@
 //= require react
 //= require react_ujs
 //= require components
+//= require react-rails-hot-loader
 //= require_tree .

config/initializers/react_rails_hot_loader.rb

@@ -0,0 +1,3 @@
+if Rails.env.development?
+  React::Rails::HotLoader.start()
+end