Resolve Class references by name when not caching subscribers

lib/entity_store/event_bus.rb

@@ -69,12 +69,25 @@ def subscribers
         case subscriber
         when String
           EntityStore::Config.load_type(subscriber)
+        when Class
+          resolve_class_subscriber(subscriber)
         else
           subscriber
         end
       end
     end
 
+    # When cache_event_subscribers is disabled the caller is signalling that
+    # subscriber Class objects may be invalidated between dispatches (Rails
+    # autoloader reloads being the canonical case). Re-resolve by name so a
+    # fresh constant binding is used.
+    def resolve_class_subscriber(klass)
+      return klass if EntityStore::Config.cache_event_subscribers
+      return klass if klass.name.nil?
+
+      EntityStore::Config.load_type(klass.name)
+    end
+
     def publish_to_feed(entity_type, event)
       feed_store.add_event(entity_type, event) if feed_store
     end

spec/entity_store/event_bus_spec.rb

@@ -69,6 +69,45 @@ class DummyExternalStore
     end
   end
 
+  describe "#subscribers" do
+    context "when cache_event_subscribers is disabled" do
+      before(:each) do
+        EntityStore::Config.stub(:cache_event_subscribers).and_return(false)
+        EntityStore::Config.stub(:event_subscribers).and_return([DummySubscriber])
+      end
+
+      it "re-resolves Class entries by name via load_type" do
+        EntityStore::Config.should_receive(:load_type).with('DummySubscriber').and_return(DummySubscriber)
+        expect(@event_bus.subscribers).to eq([DummySubscriber])
+      end
+    end
+
+    context "when cache_event_subscribers is enabled" do
+      before(:each) do
+        EntityStore::Config.stub(:cache_event_subscribers).and_return(true)
+        EntityStore::Config.stub(:event_subscribers).and_return([DummySubscriber])
+      end
+
+      it "returns Class entries unchanged without invoking load_type" do
+        EntityStore::Config.should_not_receive(:load_type).with('DummySubscriber')
+        expect(@event_bus.subscribers).to eq([DummySubscriber])
+      end
+    end
+
+    context "when given an anonymous Class with cache_event_subscribers disabled" do
+      before(:each) do
+        EntityStore::Config.stub(:cache_event_subscribers).and_return(false)
+        @anonymous = Class.new
+        EntityStore::Config.stub(:event_subscribers).and_return([@anonymous])
+      end
+
+      it "returns the Class unchanged" do
+        EntityStore::Config.should_not_receive(:load_type)
+        expect(@event_bus.subscribers).to eq([@anonymous])
+      end
+    end
+  end
+
   describe ".publish_to_feed" do
     before(:each) do
       @feed_store = double(DummyExternalStore)