iluwatar#113 Event Driven Architecture

Adds unit test to assert and verify pattern behaviour

event-driven-architecture/pom.xml

@@ -18,6 +18,11 @@
             <artifactId>junit</artifactId>
             <scope>test</scope>
         </dependency>
-    </dependencies>
 
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
 </project>

event-driven-architecture/src/main/java/com/iluwatar/eda/EventDispatcher.java

@@ -39,4 +39,12 @@ public void registerChannel(Class<? extends Event> contentType,
   public void dispatch(Event content) {
     handlers.get(content.getClass()).dispatch(content);
   }
+
+  /**
+   * Returns a map of registered event handlers.
+   * @return {@Map} of registered event handlers.
+   */
+  public Map<Class<? extends Event>, Channel<?>> getHandlers() {
+    return handlers;
+  }
 }

event-driven-architecture/src/main/java/com/iluwatar/eda/event/UserCreatedEvent.java

@@ -15,7 +15,6 @@ public UserCreatedEvent(User user) {
     this.user = user;
   }
 
-
   public User getUser() {
     return user;
   }

event-driven-architecture/src/test/java/EventDrivenTest.java

@@ -0,0 +1,47 @@
+import com.iluwatar.eda.EventDispatcher;
+import com.iluwatar.eda.event.UserCreatedEvent;
+import com.iluwatar.eda.event.UserUpdatedEvent;
+import com.iluwatar.eda.handler.UserCreatedEventHandler;
+import com.iluwatar.eda.handler.UserUpdatedEventHandler;
+import com.iluwatar.eda.model.User;
+
+import org.junit.Test;
+
+
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+
+import static org.junit.Assert.assertEquals;
+
+public class EventDrivenTest {
+
+  @Test
+  public void testEventDriverPattern(){
+
+    EventDispatcher dispatcher = spy(new EventDispatcher());
+    UserCreatedEventHandler userCreatedEventHandler =  new UserCreatedEventHandler();
+    UserUpdatedEventHandler userUpdatedEventHandler = new UserUpdatedEventHandler();
+    dispatcher.registerChannel(UserCreatedEvent.class, userCreatedEventHandler);
+    dispatcher.registerChannel(UserUpdatedEvent.class, userUpdatedEventHandler);
+
+    assertEquals("Two handlers must be registered", 2, dispatcher.getHandlers().size());
+    assertEquals("UserCreatedEvent must return the UserCreatedEventHandler",
+            userCreatedEventHandler,
+            (UserCreatedEventHandler)dispatcher.getHandlers().get(UserCreatedEvent.class));
+    assertEquals("UserUpdatedEvent must be registered to the UserUpdatedEventHandler",
+            userUpdatedEventHandler,
+            (UserUpdatedEventHandler)dispatcher.getHandlers().get(UserUpdatedEvent.class));
+
+    User user = new User("iluwatar");
+
+    UserCreatedEvent userCreatedEvent = new UserCreatedEvent(user);
+    UserUpdatedEvent userUpdatedEvent = new UserUpdatedEvent(user);
+    dispatcher.dispatch(userCreatedEvent);
+    dispatcher.dispatch(userUpdatedEvent);
+
+    //verify that the events have been dispatched
+    verify(dispatcher).dispatch(userCreatedEvent);
+    verify(dispatcher).dispatch(userUpdatedEvent);
+
+  }
+}