added links route for API interactions

before tests

app.rb

@@ -41,10 +41,29 @@ class App < Roda
       code = links.filter(:url => url).first[:code]
       @message ||= "Link exists"
       @new_link = 'http://' + request.env['HTTP_HOST'] + '/' + code
-      if 'application/json' == r.headers['CONTENT_TYPE']
+      view :create   
+    end
+    r.on "links" do
+      r.post do
+        if 'application/json' != r.headers['CONTENT_TYPE']
+          return {message: "Not a valid JSON request"}.to_json
+        end
+
+        url = r.params['url']
+        if url.nil? or url.empty? 
+          response.status = 400
+          return {message: "Please enter a valid URL"}
+        end
+
+        if links.filter(:url => url).first.nil?
+          code = SecureRandom.urlsafe_base64 4
+          links.insert(url: url, code: code) 
+        end
+
+        code = links.filter(:url => url).first[:code]
+        @new_link = 'http://' + request.env['HTTP_HOST'] + '/' + code
         return {url: url, code: code, link: @new_link}.to_json
       end
-      view :create   
     end
   end
 end

spec/create_spec.rb

@@ -7,12 +7,24 @@ require 'sequel'
 require 'rspec'
 require 'rack/test'
 
+# DB initialization
+Sequel.extension :migration
+Sequel.sqlite("db/#{ENV['DB_NAME']}") do |db|
+  Sequel::Migrator.apply(db, "db/migrations")
+end
+
 def app
   App
 end
 
 describe "Submit API request to create new link" do
   include Rack::Test::Methods
+  before :each do
+    @links = Sequel.sqlite("db/#{ENV['DB_NAME']}")[:links]
+  end
+  after :each do
+    @links.delete
+  end
   it "should return link data in json format when a valid url is entered" do
     data = {
       url: 'http://google.com'