feature: add from first reference to ResourceID too (#846)

Author: csviri

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/ResourceID.java

@@ -13,6 +13,16 @@ public static ResourceID fromResource(HasMetadata resource) {
         resource.getMetadata().getNamespace());
   }
 
+  public static Optional<ResourceID> fromFirstOwnerReference(HasMetadata resource) {
+    var ownerReferences = resource.getMetadata().getOwnerReferences();
+    if (!ownerReferences.isEmpty()) {
+      return Optional.of(new ResourceID(ownerReferences.get(0).getName(),
+          resource.getMetadata().getNamespace()));
+    } else {
+      return Optional.empty();
+    }
+  }
+
   private final String name;
   private final String namespace;
 

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/source/informer/Mappers.java

@@ -30,15 +30,8 @@ public static <T extends HasMetadata> PrimaryResourcesRetriever<T> fromLabel(
   }
 
   public static <T extends HasMetadata> PrimaryResourcesRetriever<T> fromOwnerReference() {
-    return resource -> {
-      var ownerReferences = resource.getMetadata().getOwnerReferences();
-      if (!ownerReferences.isEmpty()) {
-        return Set.of(new ResourceID(ownerReferences.get(0).getName(),
-            resource.getMetadata().getNamespace()));
-      } else {
-        return Collections.emptySet();
-      }
-    };
+    return resource -> ResourceID.fromFirstOwnerReference(resource).map(Set::of)
+        .orElse(Collections.emptySet());
   }
 
   private static <T extends HasMetadata> PrimaryResourcesRetriever<T> fromMetadata(