#596 Add null-check on source for update-method invocations and set target property to null, if source is null

processor/src/main/java/org/mapstruct/ap/internal/model/PropertyMapping.java

@@ -18,6 +18,12 @@
  */
 package org.mapstruct.ap.internal.model;
 
+import static org.mapstruct.ap.internal.model.assignment.Assignment.AssignmentType.DIRECT;
+import static org.mapstruct.ap.internal.model.assignment.Assignment.AssignmentType.MAPPED;
+import static org.mapstruct.ap.internal.model.assignment.Assignment.AssignmentType.MAPPED_TYPE_CONVERTED;
+import static org.mapstruct.ap.internal.model.assignment.Assignment.AssignmentType.TYPE_CONVERTED;
+import static org.mapstruct.ap.internal.model.assignment.Assignment.AssignmentType.TYPE_CONVERTED_MAPPED;
+
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
@@ -34,6 +40,7 @@ import org.mapstruct.ap.internal.model.assignment.NewCollectionOrMapWrapper;
 import org.mapstruct.ap.internal.model.assignment.NullCheckWrapper;
 import org.mapstruct.ap.internal.model.assignment.SetterWrapper;
 import org.mapstruct.ap.internal.model.assignment.SetterWrapperForCollectionsAndMaps;
+import org.mapstruct.ap.internal.model.assignment.UpdateNullCheckWrapper;
 import org.mapstruct.ap.internal.model.assignment.UpdateWrapper;
 import org.mapstruct.ap.internal.model.common.ModelElement;
 import org.mapstruct.ap.internal.model.common.Parameter;
@@ -46,11 +53,6 @@ import org.mapstruct.ap.internal.util.Executables;
 import org.mapstruct.ap.internal.util.Message;
 import org.mapstruct.ap.internal.util.Strings;
 
-import static org.mapstruct.ap.internal.model.assignment.Assignment.AssignmentType.DIRECT;
-import static org.mapstruct.ap.internal.model.assignment.Assignment.AssignmentType.MAPPED_TYPE_CONVERTED;
-import static org.mapstruct.ap.internal.model.assignment.Assignment.AssignmentType.TYPE_CONVERTED;
-import static org.mapstruct.ap.internal.model.assignment.Assignment.AssignmentType.TYPE_CONVERTED_MAPPED;
-
 /**
  * Represents the mapping between a source and target property, e.g. from {@code String Source#foo} to
  * {@code int Target#bar}. Name and type of source and target property can differ. If they have different types, the
@@ -260,14 +262,19 @@ public class PropertyMapping extends ModelElement {
                     result = new SetterWrapper( result, method.getThrownTypes() );
                 }
                 if ( !sourceType.isPrimitive()
-                    && !sourceReference.getPropertyEntries().isEmpty() /* parameter null taken care of by beanmapper */
+                    && !sourceReference.getPropertyEntries().isEmpty() ) { // parameter null taken care of by beanmapper
-                    && ( result.getType() == TYPE_CONVERTED
+
-                    || result.getType() == TYPE_CONVERTED_MAPPED
+                    if ( result.isUpdateMethod() ) {
-                    || result.getType() == MAPPED_TYPE_CONVERTED
+                        result = new UpdateNullCheckWrapper( result );
-                    || ( result.getType() == DIRECT && targetType.isPrimitive() ) ) ) {
+                    }
-                    // for primitive types null check is not possible at all, but a conversion needs
+                    else if ( result.getType() == TYPE_CONVERTED
-                    // a null check.
+                        || result.getType() == TYPE_CONVERTED_MAPPED
-                    result = new NullCheckWrapper( result );
+                        || result.getType() == MAPPED_TYPE_CONVERTED
+                        || ( result.getType() == DIRECT && targetType.isPrimitive() ) ) {
+                        // for primitive types null check is not possible at all, but a conversion needs
+                        // a null check.
+                        result = new NullCheckWrapper( result );
+                    }
                 }
             }
             else {
@@ -354,6 +361,9 @@ public class PropertyMapping extends ModelElement {
             if ( result.getType() == DIRECT ) {
                 result = new NullCheckWrapper( result );
             }
+            else if ( result.getType() == MAPPED && result.isUpdateMethod() ) {
+                result = new UpdateNullCheckWrapper( result );
+            }
 
             return result;
         }

processor/src/main/java/org/mapstruct/ap/internal/model/assignment/UpdateNullCheckWrapper.java

@@ -0,0 +1,32 @@
+/**
+ *  Copyright 2012-2015 Gunnar Morling (http://www.gunnarmorling.de/)
+ *  and/or other contributors as indicated by the @authors tag. See the
+ *  copyright.txt file in the distribution for a full listing of all
+ *  contributors.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.mapstruct.ap.internal.model.assignment;
+
+/**
+ * Wraps an update-assignment in a null check and sets the target property to {@code null}, if the source is
+ * {@code null}.
+ *
+ * @author Andreas Gudian
+ */
+public class UpdateNullCheckWrapper extends AssignmentWrapper {
+
+    public UpdateNullCheckWrapper( Assignment decoratedAssignment ) {
+        super( decoratedAssignment );
+    }
+}

processor/src/main/resources/org/mapstruct/ap/internal/model/assignment/UpdateNullCheckWrapper.ftl

@@ -0,0 +1,31 @@
+<#--
+
+     Copyright 2012-2015 Gunnar Morling (http://www.gunnarmorling.de/)
+     and/or other contributors as indicated by the @authors tag. See the
+     copyright.txt file in the distribution for a full listing of all
+     contributors.
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+         http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+
+-->
+if ( ${sourceReference} != null ) {
+    <@includeModel object=assignment
+                targetBeanName=ext.targetBeanName
+                existingInstanceMapping=ext.existingInstanceMapping
+                targetReadAccessorName=ext.targetReadAccessorName
+                targetWriteAccessorName=ext.targetWriteAccessorName
+                targetType=ext.targetType/>
+}
+else {
+    ${ext.targetBeanName}.${ext.targetWriteAccessorName}( null );
+}

processor/src/test/java/org/mapstruct/ap/test/updatemethods/UpdateMethodsTest.java

@@ -20,9 +20,6 @@ package org.mapstruct.ap.test.updatemethods;
 
 import org.junit.Test;
 import org.junit.runner.RunWith;
-
-import static org.fest.assertions.Assertions.assertThat;
-
 import org.mapstruct.ap.testutil.IssueKey;
 import org.mapstruct.ap.testutil.WithClasses;
 import org.mapstruct.ap.testutil.compilation.annotation.CompilationResult;
@@ -30,6 +27,8 @@ import org.mapstruct.ap.testutil.compilation.annotation.Diagnostic;
 import org.mapstruct.ap.testutil.compilation.annotation.ExpectedCompilationOutcome;
 import org.mapstruct.ap.testutil.runner.AnnotationProcessorTestRunner;
 
+import static org.fest.assertions.Assertions.assertThat;
+
 /**
  *
  * @author Sjaak Derksen
@@ -85,6 +84,30 @@ public class UpdateMethodsTest {
     @WithClasses( {
         OrganizationMapper.class
     } )
+    public void testUpdateMethodClearsExistingValues() {
+
+        OrganizationEntity organizationEntity = new OrganizationEntity();
+        CompanyEntity companyEntity = new CompanyEntity();
+        organizationEntity.setCompany( companyEntity );
+        companyEntity.setName( "CocaCola" );
+        DepartmentEntity department = new DepartmentEntity( null );
+        department.setName( "recipies" );
+        companyEntity.setDepartment( department );
+
+        OrganizationDto organizationDto = new OrganizationDto();
+        organizationDto.setCompany( null );
+
+        OrganizationMapper.INSTANCE.toOrganizationEntity( organizationDto, organizationEntity );
+
+        assertThat( organizationEntity.getCompany() ).isNull();
+        assertThat( organizationEntity.getType().getType() ).isEqualTo( "commercial" );
+        assertThat( organizationEntity.getTypeNr().getNumber() ).isEqualTo( 5 );
+    }
+
+    @Test
+    @WithClasses({
+        OrganizationMapper.class
+    })
     public void testPreferUpdateMethodSourceObjectNotDefined() {
 
         OrganizationEntity organizationEntity = new OrganizationEntity();
@@ -105,7 +128,7 @@ public class UpdateMethodsTest {
         assertThat( organizationEntity.getCompany().getDepartment().getName() ).isEqualTo( "finance" );
     }
 
-  @Test
+    @Test
     @WithClasses( {
         CompanyMapper.class,
         DepartmentInBetween.class
@@ -156,7 +179,7 @@ public class UpdateMethodsTest {
     } )
     public void testShouldFailOnConstantMappingNoPropertyGetter() { }
 
-   @Test
+    @Test
     @WithClasses( {
         ErroneousCompanyMapper1.class,
         DepartmentInBetween.class