refactored missing link scenario to make more sense

+ 404 code, stay on the current page, and load the form
+ also simplified the logic for the create action if the link doesn't
  already exist

app.rb

@@ -19,11 +19,10 @@ class App < Roda
 
     r.get String do | url_code |
       link = links.filter(:code => url_code)
-      if link.first.nil?
-        flash['message'] = "Link #{url_code} doesn't exist"
-        r.redirect '/'
-      end
-      r.redirect link.first[:url]
+      r.redirect link.first[:url] unless link.first.nil?
+      @message = "Link #{url_code} doesn't exist"
+      response.status = 404
+      view :home
     end
 
     r.post "create" do
@@ -32,7 +31,7 @@ class App < Roda
         flash['message'] = "Please enter a valid URL";
         r.redirect '/'
       end
-      if nil == links.filter(:url => url).first
+      if links.filter(:url => url).first.nil?
         code = SecureRandom.urlsafe_base64 4
         links.insert(url: url, code: code) 
         @message = "Link created"

features/homepage.feature

@@ -42,5 +42,8 @@ Feature: Homepage
 
   Scenario: Accessing a nonexistent URL code
     Given I visit the "/aaaaaa" location
-    Then I should be on "/" page
+    Then I should be on "/aaaaaa" page
+    And The status code should be 404
     And I should see the message "Link aaaaaa doesn't exist"
+    And I should see a form field "url"
+    And I should see a "Submit" button

features/step_definitions/steps.rb

@@ -3,6 +3,7 @@ Before('@db-test') do
   @links = Sequel.sqlite("db/#{ENV['DB_NAME']}")[:links]
 end
 
+
 # GIVEN
 
 Given('I visit the {string} page') do |string|
@@ -17,6 +18,7 @@ Given('A link already exists with the url {string} and code {string}') do |url,
   @links.insert(url: url, code: code)
 end
 
+
 # WHEN
 
 When('I click the {string} button') do |string|
@@ -31,6 +33,7 @@ When('I visit the {string} location') do |string|
   visit string
 end
 
+
 # THEN
 
 Then('I should see text {string}') do |string|
@@ -58,6 +61,12 @@ Then('I should be redirected to {string}') do |string|
   location = actual.index(string)
   location.should equal(0)
 end
+
+Then('The status code should be {int}') do |code|
+  puts page.status_code.should eq(code)
+end
+
+
 # AFTER
 
 After('@db-test') do