Maintenance: Resolved rack-livereload issue with Rails CSP (https://github.com/johnbintz/rack-livereload/issues/71).

config/environments/development.rb

@@ -67,17 +67,4 @@ Rails.application.configure do
 
   # Raises error for missing translations
   # config.action_view.raise_on_missing_translations = true
-
-  # Automatically inject JavaScript needed for LiveReload
-  if ENV['RAKE_LIVE_RELOAD'].present?
-    require 'rack-livereload'
-    config.middleware.insert_after(
-      ActionDispatch::Static,
-      Rack::LiveReload,
-      no_swf:           true,
-      min_delay:        500,    # default 1000
-      max_delay:        10_000, # default 60_000
-      live_reload_port: 35_738
-    )
-  end
 end

config/initializers/rack_livereload.rb

@@ -0,0 +1,34 @@
+if Rails.env.development? && ENV['RAKE_LIVE_RELOAD'].present?
+
+  require 'rack-livereload'
+
+  # strongly inspired by https://github.com/johnbintz/rack-livereload/issues/71#issuecomment-674899405
+  module BodyProcessorExtension
+    def process!(env)
+      @content_security_policy_nonce = if ActionDispatch::Request.new(env).respond_to?(:content_security_policy_nonce)
+                                         ActionDispatch::Request.new(env).content_security_policy_nonce
+                                       end
+
+      super
+    end
+
+    def template
+      orignal_template = ::File.read(::File.expand_path('../../../../skel/livereload.html.erb', method(:template).super_method.source_location[0]))
+      nonced_template  = orignal_template.gsub(%r{(<script type="text/javascript")}, '\1 nonce="<%= @content_security_policy_nonce %>"')
+
+      ERB.new(nonced_template)
+    end
+  end
+
+  Rack::LiveReload::BodyProcessor.prepend(BodyProcessorExtension)
+
+  # Automatically inject JavaScript needed for LiveReload
+  Rails.application.middleware.insert_after(
+    ActionDispatch::Static,
+    Rack::LiveReload,
+    no_swf:           true,
+    min_delay:        500,    # default 1000
+    max_delay:        10_000, # default 60_000
+    live_reload_port: 35_738
+  )
+end