Reinstating object creation checks before calling object-created callbacks, test coverage for fix

Author: SteveWilkes

AgileMapper.UnitTests/Configuration/WhenConfiguringObjectCreationCallbacks.cs

@@ -446,5 +446,29 @@ public void ShouldUseATypedParentContextAccessForACallbackArgument()
                 mapper.Map(source).OnTo(target);
             }
         }
+
+        [Fact]
+        public void ShouldOnlyInvokeACallbackWhenAnObjectIsCreated()
+        {
+            using (var mapper = Mapper.CreateNew())
+            {
+                var createdInstance = default(object);
+
+                mapper.After
+                    .CreatingInstances
+                    .Call(ctx => createdInstance = ctx.CreatedObject);
+
+                var source = new PublicField<Product> { Value = new Product { ProductId = "YEAH" } };
+                var target = new PublicField<Product> { Value = new Product() };
+                mapper.Map(source).OnTo(target);
+
+                createdInstance.ShouldBeNull();
+
+                target.Value = null;
+                var result = mapper.Map(source).OnTo(target);
+
+                createdInstance.ShouldBe(result.Value);
+            }
+        }
     }
 }

AgileMapper/Configuration/UserConfiguredItemBase.cs

@@ -67,10 +67,10 @@ protected bool SourceAndTargetTypesAreTheSame(UserConfiguredItemBase otherConfig
                    ConfigInfo.HasSameTargetTypeAs(otherConfiguredItem.ConfigInfo);
         }
 
-        public virtual Expression GetConditionOrNull(IMemberMapperData mapperData)
+        public Expression GetConditionOrNull(IMemberMapperData mapperData)
             => GetConditionOrNull(mapperData, CallbackPosition.After);
 
-        protected Expression GetConditionOrNull(IMemberMapperData mapperData, CallbackPosition position)
+        protected virtual Expression GetConditionOrNull(IMemberMapperData mapperData, CallbackPosition position)
             => ConfigInfo.GetConditionOrNull(mapperData, position, TargetMember);
 
         public virtual bool AppliesTo(IBasicMapperData mapperData)

AgileMapper/ObjectPopulation/ObjectCreationCallbackFactory.cs

@@ -28,9 +28,9 @@ public override bool AppliesTo(CallbackPosition callbackPosition, IBasicMapperDa
 
         protected override bool TargetMembersMatch(IBasicMapperData mapperData) => true;
 
-        public override Expression GetConditionOrNull(IMemberMapperData mapperData)
+        protected override Expression GetConditionOrNull(IMemberMapperData mapperData, CallbackPosition position)
         {
-            var condition = GetConditionOrNull(mapperData, CallbackPosition);
+            var condition = base.GetConditionOrNull(mapperData, position);
 
             if (CallbackPosition != CallbackPosition.After)
             {