only merge detached entities

Author: Behrwind

src/main/groovy/de/triology/blog/testdataloader/EntityDeleter.groovy

@@ -75,12 +75,17 @@ class EntityDeleter implements EntityCreatedListener {
     private prepareNextEntityForDeletion() {
         def entity = entities.pop()
         try {
-            return entityManager.merge(entity)
+            return mergeNextEntityIfNotAttached(entity)
         } catch (IllegalArgumentException e) {
             LOG.debug("caught IllegalArgumentException when merging entity $entity, assuming it to be already removed", e)
             return null
         }
     }
 
-
+    private mergeNextEntityIfNotAttached(Object entity) {
+        if(!entityManager.contains(entity)) {
+            return entityManager.merge(entity)
+        }
+        return entity
+    }
 }

src/test/java/de/triology/blog/testdataloader/EntityDeleterTest.java

@@ -84,9 +84,10 @@ public void deletesAnEntityOnlyOnce() throws Exception {
     }
 
     @Test
-    public void mergesEntitiesBeforeRemovingThem() throws Exception {
+    public void mergesDetachedEntitiesBeforeRemovingThem() throws Exception {
         Object entity = new Object();
         entityDeleter.entityCreated(entity);
+        when(entityManager.contains(entity)).thenReturn(false);
 
         entityDeleter.deleteAllEntities();
 
@@ -95,6 +96,19 @@ public void mergesEntitiesBeforeRemovingThem() throws Exception {
         inOrder.verify(entityManager).remove(entity);
     }
 
+    @Test
+    public void doesNotMergeAttachedEntitiesBeforeRemovingThem() throws Exception {
+        Object entity = new Object();
+        entityDeleter.entityCreated(entity);
+        when(entityManager.contains(entity)).thenReturn(true);
+
+        entityDeleter.deleteAllEntities();
+
+        InOrder inOrder = inOrder(entityManager);
+        inOrder.verify(entityManager, never()).merge(entity);
+        inOrder.verify(entityManager).remove(entity);
+    }
+
     @Test
     public void doesNotDeleteAlreadyRemovedEntities() throws Exception {
         Object entity = new Object();