Fixes #38 Implement repo.delete

java/newton-sample/src/main/java/io/muoncore/newton/todo/UniqueTaskDescriptionDomainService.java

@@ -3,12 +3,14 @@
 import io.muoncore.newton.EventHandler;
 import io.muoncore.newton.StreamSubscriptionManager;
 import io.muoncore.newton.UniqueAggregateDomainService;
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Component;
 
 import java.io.IOException;
 
 @Component
+@Slf4j
 public class UniqueTaskDescriptionDomainService extends UniqueAggregateDomainService<String> {
 
   @Autowired
@@ -23,6 +25,7 @@ protected String[] eventStreams() {
 
   @EventHandler
   public void handle(TaskCreatedEvent event){
+    log.info("Processing event into view {}", event);
     if (event.getDescription().equals("exception")){
       throw new RuntimeException("Unique name exception....");
     }

java/newton-spring-starter/src/main/java/io/muoncore/newton/AggregateRoot.java

@@ -1,10 +1,15 @@
 package io.muoncore.newton;
 
+import io.muoncore.newton.eventsource.AggregateDeletedEvent;
+import lombok.Getter;
+
 import java.util.ArrayList;
 import java.util.List;
 
 public abstract class AggregateRoot<T> {
 
+  @Getter
+  private boolean deleted;
 	private long version;
 	private transient DynamicInvokeEventAdaptor eventAdaptor = new DynamicInvokeEventAdaptor(this, EventHandler.class);
 
@@ -26,6 +31,13 @@ public List<NewtonEvent> getNewOperations() {
 	}
 
 	public void handleEvent(NewtonEvent event) {
+
+	  if (event instanceof AggregateDeletedEvent) {
+	    deleted = true;
+	    version++;
+	    return;
+    }
+
 		boolean eventHandled = eventAdaptor.apply(event);
 
 		if (!eventHandled) {

java/newton-spring-starter/src/main/java/io/muoncore/newton/eventsource/AggregateDeletedEvent.java

@@ -0,0 +1,11 @@
+package io.muoncore.newton.eventsource;
+
+import io.muoncore.newton.NewtonEvent;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+@Getter
+@AllArgsConstructor
+public class AggregateDeletedEvent implements NewtonEvent<Object> {
+  private Object id;
+}

java/newton-spring-starter/src/main/java/io/muoncore/newton/eventsource/EventSourceRepository.java

@@ -35,6 +35,13 @@ public interface EventSourceRepository<A extends AggregateRoot> {
    */
 	List<NewtonEvent> save(A aggregate);
 
+  /**
+   * Delete this aggregate root. Its events may still be retrievable via replay, however a call to `load` will throw
+   * AggregateNotFoundException
+   * @param aggregate
+   */
+	List<NewtonEvent> delete(A aggregate);
+
   /**
    * Cold replay of the event contents of an aggregate root.
    */

java/newton-spring-starter/src/main/java/io/muoncore/newton/eventsource/muon/MuonEventSourceRepository.java

@@ -2,10 +2,7 @@
 
 import io.muoncore.newton.AggregateRoot;
 import io.muoncore.newton.NewtonEvent;
-import io.muoncore.newton.eventsource.AggregateNotFoundException;
-import io.muoncore.newton.eventsource.AggregateRootUtil;
-import io.muoncore.newton.eventsource.EventSourceRepository;
-import io.muoncore.newton.eventsource.OptimisticLockException;
+import io.muoncore.newton.eventsource.*;
 import io.muoncore.newton.utils.muon.MuonLookupUtils;
 import io.muoncore.protocol.event.ClientEvent;
 import io.muoncore.protocol.event.Event;
@@ -47,6 +44,7 @@ public A load(Object aggregateIdentifier) {
 		try {
 			A aggregate = aggregateType.newInstance();
 			replayEvents(aggregateIdentifier).forEach(aggregate::handleEvent);
+			if (aggregate.isDeleted()) throw new AggregateNotFoundException(aggregateIdentifier);
 			return aggregate;
 		} catch (AggregateNotFoundException e) {
 			throw e;
@@ -89,6 +87,12 @@ public List<NewtonEvent> save(A aggregate) {
 		return events;
 	}
 
+  @Override
+  public List<NewtonEvent> delete(A aggregate) {
+    aggregate.getNewOperations().add(new AggregateDeletedEvent(aggregate.getId()));
+    return save(aggregate);
+  }
+
   private Publisher<NewtonEvent> subscribe(Object aggregateIdentifier, EventReplayMode mode) {
 	  return sub -> eventClient.replay("/aggregate/" + aggregateIdentifier.toString(), mode, new Subscriber<Event>() {
         public void onSubscribe(Subscription s) {

java/newton-spring-starter/src/test/java/io/muoncore/newton/eventsource/muon/MuonEventSourceRepositoryTest.java

@@ -3,6 +3,7 @@
 import io.muoncore.eventstore.TestEventStore;
 import io.muoncore.newton.MuonTestConfiguration;
 import io.muoncore.newton.NewtonEvent;
+import io.muoncore.newton.eventsource.AggregateDeletedEvent;
 import io.muoncore.newton.eventsource.AggregateNotFoundException;
 import io.muoncore.newton.eventsource.OptimisticLockException;
 import io.muoncore.newton.mongo.MongoConfiguration;
@@ -62,6 +63,30 @@ public void save() throws Exception {
 		assertEquals(TestAggregateCreated.class.getSimpleName(), events.get(0).getEventType());
 	}
 
+  @Test
+  public void deleteCreatesDeletedEvent() throws Exception {
+    String id = UUID.randomUUID().toString();
+    TestAggregate customer = new TestAggregate(id);
+    repository.save(customer);
+
+    repository.delete(customer);
+
+    List<Event> events = client.loadAggregateRoot(id.toString());
+
+    assertEquals(2, events.size());
+    assertEquals(AggregateDeletedEvent.class.getSimpleName(), events.get(1).getEventType());
+  }
+
+  @Test(expected = AggregateNotFoundException.class)
+  public void loadDeletedAggregateThrowsException() throws Exception {
+    String id = UUID.randomUUID().toString();
+    TestAggregate customer = new TestAggregate(id);
+    repository.save(customer);
+    repository.delete(customer);
+
+    repository.load(id);
+  }
+
 	@Test(expected = AggregateNotFoundException.class)
 	public void throwsExceptionOnNonExistingAggregate() {
 		repository.load("no-such-id-as-this");