#10 Raising error in case a property can not be mapped

processor/src/main/java/org/mapstruct/ap/MapperGenerationVisitor.java

@@ -69,6 +69,8 @@ public class MapperGenerationVisitor extends ElementKindVisitor6<Void, Void> {
     private final TypeUtil typeUtil;
     private final Options options;
 
+    private boolean mappingErronuous = false;
+
     public MapperGenerationVisitor(ProcessingEnvironment processingEnvironment, Options options) {
         this.processingEnvironment = processingEnvironment;
         this.typeUtils = processingEnvironment.getTypeUtils();
@@ -80,9 +82,11 @@ public class MapperGenerationVisitor extends ElementKindVisitor6<Void, Void> {
     @Override
     public Void visitTypeAsInterface(TypeElement element, Void p) {
         Mapper model = retrieveModel( element );
-        String sourceFileName = element.getQualifiedName() + IMPLEMENTATION_SUFFIX;
 
-        writeModelToSourceFile( sourceFileName, model );
+        if ( !mappingErronuous ) {
+            String sourceFileName = element.getQualifiedName() + IMPLEMENTATION_SUFFIX;
+            writeModelToSourceFile( sourceFileName, model );
+        }
 
         return null;
     }
@@ -153,9 +157,17 @@ public class MapperGenerationVisitor extends ElementKindVisitor6<Void, Void> {
             for ( MappedProperty property : method.getMappedProperties() ) {
                 Method propertyMappingMethod = getPropertyMappingMethod( methods, property );
                 Method reversePropertyMappingMethod = getReversePropertyMappingMethod( methods, property );
-
                 Conversion conversion = conversions.getConversion( property.getSourceType(), property.getTargetType() );
 
+                reportErrorIfPropertyCanNotBeMapped(
+                    method,
+                    rawReverseMappingMethod,
+                    property,
+                    propertyMappingMethod,
+                    reversePropertyMappingMethod,
+                    conversion
+                );
+
                 propertyMappings.add(
                     new PropertyMapping(
                         property.getSourceReadAccessorName(),
@@ -222,6 +234,48 @@ public class MapperGenerationVisitor extends ElementKindVisitor6<Void, Void> {
         return mappings;
     }
 
+    private void reportErrorIfPropertyCanNotBeMapped(Method method, Method reverseMethod, MappedProperty property, Method propertyMappingMethod, Method reversePropertyMappingMethod, Conversion conversion) {
+        if ( property.getSourceType().equals( property.getTargetType() ) ||
+            propertyMappingMethod != null ||
+            conversion != null ||
+            ( property.getTargetType().isCollectionType() && property.getTargetType()
+                .getCollectionImplementationType() != null ) ) {
+            return;
+        }
+
+        reportError(
+            String.format(
+                "Can't map property \"%s %s\" to \"%s %s\".",
+                property.getSourceType(),
+                property.getSourceName(),
+                property.getTargetType(),
+                property.getTargetName()
+            ),
+            method.getExecutable()
+        );
+
+        mappingErronuous = true;
+
+        if ( reverseMethod == null ||
+            reversePropertyMappingMethod != null ||
+            conversion != null ||
+            ( property.getSourceType().isCollectionType() && property.getSourceType()
+                .getCollectionImplementationType() == null ) ) {
+            return;
+        }
+
+        reportError(
+            String.format(
+                "Can't map property \"%s %s\" to \"%s %s\".",
+                property.getTargetType(),
+                property.getTargetName(),
+                property.getSourceType(),
+                property.getSourceName()
+            ),
+            reverseMethod.getExecutable()
+        );
+    }
+
     private String getIterableConversionString(Conversions conversions, Type sourceElementType, Type targetElementType, boolean isToConversion) {
         Conversion conversion = conversions.getConversion( sourceElementType, targetElementType );
 
@@ -300,7 +354,7 @@ public class MapperGenerationVisitor extends ElementKindVisitor6<Void, Void> {
             methods.add(
                 new Method(
                     declaringMapper,
-                    method.getSimpleName().toString(),
+                    method,
                     parameter.getName(),
                     parameter.getType(),
                     returnType,
@@ -310,21 +364,11 @@ public class MapperGenerationVisitor extends ElementKindVisitor6<Void, Void> {
 
             if ( declaringMapper == null ) {
                 if ( parameter.getType().isIterableType() && !returnType.isIterableType() ) {
-                    processingEnvironment.getMessager()
+                    reportError( "Can't generate mapping method from iterable type to non-iterable ype.", method );
-                        .printMessage(
-                            Kind.ERROR,
-                            "Can't generate mapping method from iterable type to non-iterable ype.",
-                            method
-                        );
                 }
 
                 if ( !parameter.getType().isIterableType() && returnType.isIterableType() ) {
-                    processingEnvironment.getMessager()
+                    reportError( "Can't generate mapping method from non-iterable type to iterable ype.", method );
-                        .printMessage(
-                            Kind.ERROR,
-                            "Can't generate mapping method from non-iterable type to iterable ype.",
-                            method
-                        );
                 }
             }
         }
@@ -434,4 +478,9 @@ public class MapperGenerationVisitor extends ElementKindVisitor6<Void, Void> {
     private Type retrieveReturnType(ExecutableElement method) {
         return typeUtil.retrieveType( method.getReturnType() );
     }
+
+    private void reportError(String message, Element element) {
+        processingEnvironment.getMessager().printMessage( Kind.ERROR, message, element );
+        mappingErronuous = true;
+    }
 }

processor/src/main/java/org/mapstruct/ap/model/source/Method.java

@@ -19,6 +19,7 @@
 package org.mapstruct.ap.model.source;
 
 import java.util.List;
+import javax.lang.model.element.ExecutableElement;
 
 import org.mapstruct.ap.model.Type;
 
@@ -26,19 +27,15 @@ import org.mapstruct.ap.model.Type;
 public class Method {
 
     private final Type declaringMapper;
-    private final String name;
+    private final ExecutableElement executable;
     private final String parameterName;
     private final Type sourceType;
     private final Type targetType;
     private final List<MappedProperty> mappedProperties;
 
-    public Method(String name, String parameterName, Type sourceType, Type targetType, List<MappedProperty> mappedProperties) {
+    public Method(Type declaringMapper, ExecutableElement executable, String parameterName, Type sourceType, Type targetType, List<MappedProperty> mappedProperties) {
-        this( null, name, parameterName, sourceType, targetType, mappedProperties );
-    }
-
-    public Method(Type declaringMapper, String name, String parameterName, Type sourceType, Type targetType, List<MappedProperty> mappedProperties) {
         this.declaringMapper = declaringMapper;
-        this.name = name;
+        this.executable = executable;
         this.parameterName = parameterName;
         this.sourceType = sourceType;
         this.targetType = targetType;
@@ -49,8 +46,12 @@ public class Method {
         return declaringMapper;
     }
 
+    public ExecutableElement getExecutable() {
+        return executable;
+    }
+
     public String getName() {
-        return name;
+        return executable.getSimpleName().toString();
     }
 
     public String getParameterName() {
@@ -81,6 +82,6 @@ public class Method {
 
     @Override
     public String toString() {
-        return targetType + " " + name + "(" + sourceType + " " + parameterName + ")";
+        return targetType + " " + getName() + "(" + sourceType + " " + parameterName + ")";
     }
 }

processor/src/main/resources/mapper-implementation.ftl

@@ -150,12 +150,12 @@ public class ${implementationName} implements ${interfaceName} {
         <#-- b) invoke mapping method -->
         <#elseif mappingMethod != "">
         ${targetBeanName}.${targetAccessorName}( <#if mappingMethod.declaringMapper??>${mappingMethod.declaringMapper.name?uncap_first}.</#if>${mappingMethod.name}( ${sourceBeanName}.${sourceAccessorName}() ) );
+        <#-- c) simply set -->
         <#else>
             <#if targetType.collectionType == true>
         if ( ${sourceBeanName}.${sourceAccessorName}() != null ) {
             ${targetBeanName}.${targetAccessorName}( new <#if targetType.collectionImplementationType??>${targetType.collectionImplementationType.name}<#else>${targetType.name}</#if><#if targetType.elementType??><${targetType.elementType.name}></#if>( ${sourceBeanName}.${sourceAccessorName}() ) );
         }
-        <#-- c) simply set -->
             <#else>
         ${targetBeanName}.${targetAccessorName}( ${sourceBeanName}.${sourceAccessorName}() );
             </#if>

processor/src/test/java/org/mapstruct/ap/test/erronuous/ErronuousMapper.java

@@ -0,0 +1,29 @@
+/**
+ *  Copyright 2012-2013 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.test.erronuous;
+
+import org.mapstruct.Mapper;
+
+@Mapper
+public interface ErronuousMapper {
+
+    Target sourceToTarget(Source source);
+
+    Source targetToSource(Target target);
+}

processor/src/test/java/org/mapstruct/ap/test/erronuous/MappedPropertiesWithDifferentTypesTest.java

@@ -0,0 +1,45 @@
+/**
+ *  Copyright 2012-2013 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.test.erronuous;
+
+import javax.tools.Diagnostic.Kind;
+
+import org.mapstruct.ap.testutil.IssueKey;
+import org.mapstruct.ap.testutil.MapperTestBase;
+import org.mapstruct.ap.testutil.WithClasses;
+import org.mapstruct.ap.testutil.compilation.annotation.CompilationResult;
+import org.mapstruct.ap.testutil.compilation.annotation.Diagnostic;
+import org.mapstruct.ap.testutil.compilation.annotation.ExpectedCompilationOutcome;
+import org.testng.annotations.Test;
+
+@WithClasses({ ErronuousMapper.class, Source.class, Target.class })
+public class MappedPropertiesWithDifferentTypesTest extends MapperTestBase {
+
+    @Test
+    @IssueKey("6")
+    @ExpectedCompilationOutcome(
+        value = CompilationResult.FAILED,
+        diagnostics = {
+            @Diagnostic(type = ErronuousMapper.class, kind = Kind.ERROR, line = 26),
+            @Diagnostic(type = ErronuousMapper.class, kind = Kind.ERROR, line = 28)
+        }
+    )
+    public void shouldFailToGenerateMappingFromListToString() {
+    }
+}

processor/src/test/java/org/mapstruct/ap/test/erronuous/Source.java

@@ -0,0 +1,32 @@
+/**
+ *  Copyright 2012-2013 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.test.erronuous;
+
+public class Source {
+
+    private boolean foo;
+
+    public boolean isFoo() {
+        return foo;
+    }
+
+    public void setFoo(boolean foo) {
+        this.foo = foo;
+    }
+}

processor/src/test/java/org/mapstruct/ap/test/erronuous/Target.java

@@ -0,0 +1,32 @@
+/**
+ *  Copyright 2012-2013 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.test.erronuous;
+
+public class Target {
+
+    private int foo;
+
+    public int getFoo() {
+        return foo;
+    }
+
+    public void setFoo(int foo) {
+        this.foo = foo;
+    }
+}