GH-253 - Fix verifications for aggregate references as collection ele…

…ments.

Original pull reuqest: GH-254.

jmolecules-archunit/src/main/java/org/jmolecules/archunit/JMoleculesDddRules.java

@@ -35,6 +35,8 @@
 import com.tngtech.archunit.base.DescribedPredicate;
 import com.tngtech.archunit.core.domain.JavaClass;
 import com.tngtech.archunit.core.domain.JavaField;
+import com.tngtech.archunit.core.domain.JavaParameterizedType;
+import com.tngtech.archunit.core.domain.JavaType;
 import com.tngtech.archunit.core.domain.properties.CanBeAnnotated;
 import com.tngtech.archunit.lang.ArchCondition;
 import com.tngtech.archunit.lang.ArchRule;
@@ -58,7 +60,8 @@
  * @author Oliver Drotbohm
  * @author Torsten Juergeleit
  * @author Hasan Kara
- * @see <a href="http://scabl.blogspot.com/2015/04/aeddd-9.html">Advancing Enterprise DDD - Reinstating the Aggregate</a>
+ * @see <a href="http://scabl.blogspot.com/2015/04/aeddd-9.html">Advancing Enterprise DDD - Reinstating the
+ *      Aggregate</a>
  */
 public class JMoleculesDddRules {
 
@@ -146,7 +149,8 @@ public static ArchRule entitiesShouldBeDeclaredForUseInSameAggregate() {
 	public static ArchRule aggregateReferencesShouldBeViaIdOrAssociation() {
 
 		DescribedPredicate<JavaField> referenceAnAggregateRoot = areAssignableTo(AggregateRoot.class)
-				.or(hasFieldTypeAnnotatedWith(org.jmolecules.ddd.annotation.AggregateRoot.class));
+				.or(hasFieldTypeAnnotatedWith(org.jmolecules.ddd.annotation.AggregateRoot.class))
+				.or(hasParameterizedFieldOfTypeAnnotatedWith(org.jmolecules.ddd.annotation.AggregateRoot.class));
 
 		return ArchRuleDefinition.fields() //
 				.that(new OwnerMatches(IS_IDENTIFIABLE).and(referenceAnAggregateRoot)) //
@@ -194,6 +198,11 @@ private static FieldTypeIsAnnotatedWith hasFieldTypeAnnotatedWith(Class<? extend
 		return new FieldTypeIsAnnotatedWith(type);
 	}
 
+	private static DescribedPredicate<? super JavaField> hasParameterizedFieldOfTypeAnnotatedWith(
+			Class<? extends Annotation> type) {
+		return new ParameterizedFieldOfTypeAnnotatedWith(type);
+	}
+
 	private static class IsDeclaredToUseTheSameAggregate extends ArchCondition<JavaField> {
 
 		private static final ResolvableType COLLECTION_TYPE = ResolvableType.forClass(Collection.class);
@@ -284,6 +293,37 @@ public boolean test(JavaField input) {
 		}
 	}
 
+	private static class ParameterizedFieldOfTypeAnnotatedWith extends DescribedPredicate<JavaField> {
+
+		private final DescribedPredicate<CanBeAnnotated> isAnnotatedWith;
+
+		public ParameterizedFieldOfTypeAnnotatedWith(Class<? extends Annotation> type) {
+
+			super("is collection of type annotated with %s", type.getSimpleName());
+
+			this.isAnnotatedWith = CanBeAnnotated.Predicates.annotatedWith(type);
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see java.util.function.Predicate#test(java.lang.Object)
+		 */
+		@Override
+		public boolean test(JavaField input) {
+
+			if (!(input.getType() instanceof JavaParameterizedType)) {
+				return false;
+			}
+
+			JavaParameterizedType parameterizedType = (JavaParameterizedType) input.getType();
+
+			return parameterizedType.getActualTypeArguments()
+					.stream()
+					.map(JavaType::toErasure)
+					.anyMatch(isAnnotatedWith);
+		}
+	}
+
 	private static class IsAssignableTypeField extends DescribedPredicate<JavaField> {
 
 		private static final ResolvableType COLLECTION_TYPE = ResolvableType.forClass(Collection.class);

jmolecules-archunit/src/test/java/org/jmolecules/archunit/JMoleculesDddRulesUnitTest.java

@@ -65,7 +65,11 @@ void detectsViolations(JavaClasses classes) {
 						violation(SampleValueObject.class, "annotatedEntity", AnnotatedEntity.class, null),
 						violation(SampleValueObject.class, "aggregate", SampleAggregate.class, null),
 						violation(SampleValueObject.class, "annotatedAggregate", AnnotatedAggregate.class, null),
-						violation(SampleGrandChildEntity.class, "otherEntity", OtherEntity.class, OtherAggregate.class) // GH-222
+						violation(SampleGrandChildEntity.class, "otherEntity", OtherEntity.class, OtherAggregate.class), // GH-222
+						violation(OtherAnnotatedAggregate.class, "invalidAnnotatedAggregate", AnnotatedAggregate.class, null), //
+						violation(OtherAnnotatedAggregate.class, "invalidAnnotatedAggregateInCollection", Collection.class,
+								Association.class), //
+						violation(OtherAnnotatedAggregate.class, "invalidAnnotatedAggregateInMap", Map.class, Association.class) //
 				);
 	}
 
@@ -123,4 +127,20 @@ static class SampleValueObject implements ValueObject {
 		SampleAggregate aggregate;
 		AnnotatedAggregate annotatedAggregate;
 	}
+
+	@org.jmolecules.ddd.annotation.AggregateRoot
+	static class OtherAnnotatedAggregate {
+
+		@org.jmolecules.ddd.annotation.Identity Long id;
+		AnnotatedAggregate invalidAnnotatedAggregate;
+		Collection<AnnotatedAggregate> invalidAnnotatedAggregateInCollection;
+		Map<String, AnnotatedAggregate> invalidAnnotatedAggregateInMap;
+	}
+
+	@org.jmolecules.ddd.annotation.AggregateRoot
+	static class ThirdAnnotatedAggregate {
+
+		@org.jmolecules.ddd.annotation.Identity Long id;
+		AnnotatedEntity valid;
+	}
 }