Fix Rails 5 support

It turns out that ActionDispatch::Request no longer inherits from
Rack::Request in Rails 5, so we had to add in direct support for
ActionDispatch::Request.

lib/voight_kampff.rb

@@ -1,7 +1,8 @@
 require 'json'
 
 require 'voight_kampff/test'
-require 'voight_kampff/rack_request' if defined?(Rack)
+require 'voight_kampff/methods'
+require 'voight_kampff/rack_request' if defined?(Rack::Request)
 require 'voight_kampff/engine' if defined?(Rails)
 
 module VoightKampff

lib/voight_kampff/engine.rb

@@ -3,5 +3,11 @@ class Engine < Rails::Engine
     rake_tasks do
       load 'tasks/voight_kampff.rake'
     end
+
+    initializer :add_voight_kampff_methods do |app|
+      ActionDispatch::Request.class_eval do
+        include VoightKampff::Methods
+      end
+    end
   end
 end

lib/voight_kampff/methods.rb

@@ -0,0 +1,10 @@
+module VoightKampff::Methods
+  def human?
+    VoightKampff::Test.new(user_agent).human?
+  end
+
+  def bot?
+    VoightKampff::Test.new(user_agent).bot?
+  end
+  alias :replicant? :bot?
+end

lib/voight_kampff/rack_request.rb

@@ -1,11 +1,4 @@
 # Reopen the Rack::Request class to add bot detection methods
-class Rack::Request
-  def human?
-    VoightKampff::Test.new(user_agent).human?
-  end
-
-  def bot?
-    VoightKampff::Test.new(user_agent).bot?
-  end
-  alias :replicant? :bot?
+Rack::Request.class_eval do
+  include VoightKampff::Methods
 end

spec/controllers/replicants_controller_spec.rb

@@ -3,7 +3,7 @@
 describe ReplicantsController, type: :controller do
   let(:user_agent_string) { '' }
   before do
-    expect(request).to receive(:user_agent).and_return user_agent_string
+    expect_any_instance_of(ActionController::TestRequest).to receive(:user_agent).and_return user_agent_string
     get :index
   end
 

voight_kampff.gemspec

@@ -23,7 +23,7 @@ Gem::Specification.new do |s|
 
   s.add_dependency 'rack', ['>= 1.4', '< 3.0']
 
-  s.add_development_dependency 'rails', '~> 4.2'
+  s.add_development_dependency 'rails', '~> 5.0'
   s.add_development_dependency 'rspec-rails', '~> 3.3'
   s.add_development_dependency 'combustion', '~> 0.5'
 end