Fix #3: undefined method call for nil:NilClass.

Author: dblock

Gemfile

@@ -3,6 +3,7 @@ source 'https://rubygems.org'
 ruby '2.3.1'
 
 gem 'slack-ruby-bot-server', '~> 0.4.0'
+gem 'rack-server-pages', github: 'dblock/rack-server-pages', branch: 'next'
 gem 'newrelic-slack-ruby-bot'
 
 group :test do

Gemfile.lock

@@ -1,3 +1,11 @@
+GIT
+  remote: git://github.com/dblock/rack-server-pages.git
+  revision: e77a45f208affed84b02b379b9c4cdb181826a8d
+  branch: next
+  specs:
+    rack-server-pages (0.0.6)
+      rack
+
 GEM
   remote: https://rubygems.org/
   specs:
@@ -132,8 +140,6 @@ GEM
       rack (>= 0.4)
     rack-cors (0.4.0)
     rack-rewrite (1.5.1)
-    rack-server-pages (0.0.6)
-      rack
     rack-test (0.6.3)
       rack (>= 1.0)
     rails-dom-testing (2.0.1)
@@ -219,6 +225,7 @@ DEPENDENCIES
   fabrication
   faker
   newrelic-slack-ruby-bot
+  rack-server-pages!
   rake
   rspec
   slack-ruby-bot-server (~> 0.4.0)
@@ -229,4 +236,4 @@ RUBY VERSION
    ruby 2.3.1p112
 
 BUNDLED WITH
-   1.13.5
+   1.13.6

spec/requests/robots_spec.rb

@@ -0,0 +1,15 @@
+require 'spec_helper'
+
+describe 'Robots.txt', type: :request do
+  include Rack::Test::Methods
+
+  def app
+    SlackRubyBotServer::Api::Middleware.instance
+  end
+
+  it 'can be retrieved' do
+    get '/robots.txt'
+    expect(last_response.status).to eq 200
+    expect(last_response.body).to eq ['User-Agent: *', 'Disallow: /'].join("\n")
+  end
+end