calculate ids if none are available

app/models/agents/rss_agent.rb

@@ -55,10 +55,11 @@ module Agents
         feed.clean! if interpolated['clean'] == 'true'
         created_event_count = 0
         feed.entries.each do |entry|
-          if check_and_track(entry.id)
+          entry_id = get_entry_id(entry)
+          if check_and_track(entry_id)
             created_event_count += 1
             create_event(:payload => {
-              :id => entry.id,
+              :id => entry_id,
               :date_published => entry.date_published,
               :last_updated => entry.last_updated,
               :urls => entry.urls,
@@ -78,6 +79,10 @@ module Agents
 
     protected
 
+    def get_entry_id(entry)
+      entry.id.presence || Digest::MD5.hexdigest(entry.content)
+    end
+
     def check_and_track(entry_id)
       memory['seen_ids'] ||= []
       if memory['seen_ids'].include?(entry_id)

spec/models/agents/rss_agent_spec.rb

@@ -8,10 +8,11 @@ describe Agents::RssAgent do
     }
 
     stub_request(:any, /github.com/).to_return(:body => File.read(Rails.root.join("spec/data_fixtures/github_rss.atom")), :status => 200)
+    stub_request(:any, /SlickdealsnetFP/).to_return(:body => File.read(Rails.root.join("spec/data_fixtures/slickdeals.atom")), :status => 200)
   end
 
   let(:agent) do
-    _agent = Agents::RssAgent.new(:name => "github rss feed", :options => @valid_options)
+    _agent = Agents::RssAgent.new(:name => "rss feed", :options => @valid_options)
     _agent.user = users(:bob)
     _agent.save!
     _agent
@@ -78,4 +79,17 @@ describe Agents::RssAgent do
       agent.memory['seen_ids'].length.should == 500
     end
   end
+
+  context "when no ids are available" do
+    before do
+      @valid_options['url'] = 'http://feeds.feedburner.com/SlickdealsnetFP?format=atom'
+    end
+
+    it "calculates content MD5 sums" do
+      lambda {
+        agent.check
+      }.should change { agent.events.count }.by(79)
+      agent.memory['seen_ids'].should == agent.events.map {|e| Digest::MD5.hexdigest(e.payload['content']) }
+    end
+  end
 end