add tests for ErrorReport#should_keep?

app/controllers/notices_controller.rb

@@ -18,7 +18,7 @@ def create
         end
         render :xml => api_xml
       else
-        render :xml => "Notice for old app version ignored"
+        render :text => "Notice for old app version ignored"
       end
     else
       render :text => "Your API key is unknown", :status => 422

spec/controllers/notices_controller_spec.rb

@@ -6,7 +6,7 @@
   let(:notice) { Fabricate(:notice) }
   let(:xml) { Rails.root.join('spec','fixtures','hoptoad_test_notice.xml').read }
   let(:app) { Fabricate(:app) }
-  let(:error_report) { double(:valid? => true, :generate_notice! => true, :notice => notice) }
+  let(:error_report) { double(:valid? => true, :generate_notice! => true, :notice => notice, :should_keep? => true) }
 
   context 'notices API' do
     context "with all params" do

spec/models/error_report_spec.rb

@@ -230,5 +230,35 @@ def framework
       end
     end
 
+    describe "#should_keep?" do
+      context "with current app version not set" do
+        before do
+          error_report.app.current_app_version = nil
+          error_report.server_environment['app-version'] = '1.0'
+        end
+
+        it "return true" do
+          expect(error_report.should_keep?).to be true
+        end
+      end
+
+      context "with current app version set" do
+        before do
+          error_report.app.current_app_version = '1.0'
+        end
+
+        it "return true if current or newer" do
+          error_report.server_environment['app-version'] = '1.0'
+          expect(error_report.should_keep?).to be true
+        end
+
+        it "return false if older" do
+          error_report.server_environment['app-version'] = '0.9'
+          expect(error_report.should_keep?).to be false
+        end
+      end
+
+    end
+
   end
 end