added URL validation to webpage part

+ URL that returns a 404
+ URL where the domain does not resolve with DNS
+ URL that is not properly formatted

app.rb

@@ -34,6 +34,20 @@ class App < Roda
         flash['message'] = "Please enter a valid URL";
         r.redirect '/'
       end
+
+      begin
+        OpenURI.open_uri(url)
+      rescue URI::BadURIError
+        flash['message'] = "Invalid URL"
+        r.redirect '/'
+      rescue OpenURI::HTTPError
+        flash['message'] = "URL not found"
+        r.redirect '/'
+      rescue SocketError => e
+        flash['message'] = "URL does not resolve"
+        r.redirect '/'
+      end
+
       if links.filter(:url => url).first.nil?
         code = SecureRandom.urlsafe_base64 4
         links.insert(url: url, code: code) 

features/step_definitions/steps.rb

@@ -63,7 +63,7 @@ Then('I should be redirected to {string}') do |string|
 end
 
 Then('The status code should be {int}') do |code|
-  puts page.status_code.should eq(code)
+  page.status_code.should eq(code)
 end
 
 

features/submit.feature

@@ -26,3 +26,27 @@ Feature: Submit
     And I click the "Submit" button
     Then I should be on "/create" page
     And I should see the message "Link exists"
+
+  @db-test
+  Scenario: Submitting the form with a URL that is 404
+    Given I visit the "/" page
+    When I type "http://google.com/example" in the "url" field
+    And I click the "Submit" button
+    Then I should be on "/" page
+    And I should see the message "URL not found"
+
+  @db-test
+  Scenario: Submitting the form with a URL that does not resolve
+    Given I visit the "/" page
+    When I type "http://bad.tld" in the "url" field
+    And I click the "Submit" button
+    Then I should be on "/" page
+    And I should see the message "URL does not resolve"
+
+  @db-test
+  Scenario: Submitting the form with an invalid URL
+    Given I visit the "/" page
+    When I type "not-an-url" in the "url" field
+    And I click the "Submit" button
+    Then I should be on "/" page
+    And I should see the message "Invalid URL"