Raising an error when trying to generate a mapping from primitive to reference type or vice versa

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

@@ -21,6 +21,7 @@ package org.mapstruct.ap;
 import java.beans.Introspector;
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedList;
@@ -69,7 +70,7 @@ public class MapperGenerationVisitor extends ElementKindVisitor6<Void, Void> {
     private final TypeUtil typeUtil;
     private final Options options;
 
-    private boolean mappingErronuous = false;
+    private boolean mappingErroneous = false;
 
     public MapperGenerationVisitor(ProcessingEnvironment processingEnvironment, Options options) {
         this.processingEnvironment = processingEnvironment;
@@ -83,7 +84,7 @@ public class MapperGenerationVisitor extends ElementKindVisitor6<Void, Void> {
     public Void visitTypeAsInterface(TypeElement element, Void p) {
         Mapper model = retrieveModel( element );
 
-        if ( !mappingErronuous ) {
+        if ( !mappingErroneous ) {
             String sourceFileName = element.getQualifiedName() + IMPLEMENTATION_SUFFIX;
             writeModelToSourceFile( sourceFileName, model );
         }
@@ -254,7 +255,7 @@ public class MapperGenerationVisitor extends ElementKindVisitor6<Void, Void> {
             method.getExecutable()
         );
 
-        mappingErronuous = true;
+        mappingErroneous = true;
 
         if ( reverseMethod == null ||
             reversePropertyMappingMethod != null ||
@@ -349,7 +350,29 @@ public class MapperGenerationVisitor extends ElementKindVisitor6<Void, Void> {
         for ( ExecutableElement method : methodsIn( element.getEnclosedElements() ) ) {
             Parameter parameter = retrieveParameter( method );
             Type returnType = retrieveReturnType( method );
-            List<MappedProperty> properties = retrieveMappedProperties( method );
+
+            if ( declaringMapper == null ) {
+                if ( parameter.getType().isIterableType() && !returnType.isIterableType() ) {
+                    reportError( "Can't generate mapping method from iterable type to non-iterable ype.", method );
+                }
+                if ( !parameter.getType().isIterableType() && returnType.isIterableType() ) {
+                    reportError( "Can't generate mapping method from non-iterable type to iterable ype.", method );
+                }
+                if ( parameter.getType().isPrimitive() ) {
+                    reportError( "Can't generate mapping method with primitive parameter type.", method );
+                }
+                if ( returnType.isPrimitive() ) {
+                    reportError( "Can't generate mapping method with primitive return type.", method );
+                }
+
+                if ( mappingErroneous ) {
+                    continue;
+                }
+            }
+
+            //retrieve property mappings if an implementation for the method needs to be generated
+            List<MappedProperty> properties = declaringMapper == null ? retrieveMappedProperties( method ) : Collections
+                .<MappedProperty>emptyList();
 
             methods.add(
                 new Method(
@@ -361,16 +384,6 @@ public class MapperGenerationVisitor extends ElementKindVisitor6<Void, Void> {
                     properties
                 )
             );
-
-            if ( declaringMapper == null ) {
-                if ( parameter.getType().isIterableType() && !returnType.isIterableType() ) {
-                    reportError( "Can't generate mapping method from iterable type to non-iterable ype.", method );
-                }
-
-                if ( !parameter.getType().isIterableType() && returnType.isIterableType() ) {
-                    reportError( "Can't generate mapping method from non-iterable type to iterable ype.", method );
-                }
-            }
         }
 
         MapperPrism mapperPrism = MapperPrism.getInstanceOn( element );
@@ -481,6 +494,6 @@ public class MapperGenerationVisitor extends ElementKindVisitor6<Void, Void> {
 
     private void reportError(String message, Element element) {
         processingEnvironment.getMessager().printMessage( Kind.ERROR, message, element );
-        mappingErronuous = true;
+        mappingErroneous = true;
     }
 }

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

@@ -35,4 +35,12 @@ public class Mapping {
     public String getTargetName() {
         return targetName;
     }
+
+    @Override
+    public String toString() {
+        return "Mapping {" +
+            "\n    sourceName='" + sourceName + "\'," +
+            "\n    targetName='" + targetName + "\'," +
+            "\n}";
+    }
 }

processor/src/test/java/org/mapstruct/ap/test/erroneous/ErroneousMapper.java

@@ -16,14 +16,18 @@
  *  See the License for the specific language governing permissions and
  *  limitations under the License.
  */
-package org.mapstruct.ap.test.erronuous;
+package org.mapstruct.ap.test.erroneous;
 
 import org.mapstruct.Mapper;
 
 @Mapper
-public interface ErronuousMapper {
+public interface ErroneousMapper {
 
     Target sourceToTarget(Source source);
 
     Source targetToSource(Target target);
+
+    long sourceToLong(Source source);
+
+    Source longToSource(long id);
 }

processor/src/test/java/org/mapstruct/ap/test/erroneous/ErroneousMappingsTest.java

@@ -16,7 +16,7 @@
  *  See the License for the specific language governing permissions and
  *  limitations under the License.
  */
-package org.mapstruct.ap.test.erronuous;
+package org.mapstruct.ap.test.erroneous;
 
 import javax.tools.Diagnostic.Kind;
 
@@ -28,18 +28,20 @@ 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 })
+@WithClasses({ ErroneousMapper.class, Source.class, Target.class })
-public class MappedPropertiesWithDifferentTypesTest extends MapperTestBase {
+public class ErroneousMappingsTest extends MapperTestBase {
 
     @Test
     @IssueKey("6")
     @ExpectedCompilationOutcome(
         value = CompilationResult.FAILED,
         diagnostics = {
-            @Diagnostic(type = ErronuousMapper.class, kind = Kind.ERROR, line = 26),
+            @Diagnostic(type = ErroneousMapper.class, kind = Kind.ERROR, line = 26),
-            @Diagnostic(type = ErronuousMapper.class, kind = Kind.ERROR, line = 28)
+            @Diagnostic(type = ErroneousMapper.class, kind = Kind.ERROR, line = 28),
+            @Diagnostic(type = ErroneousMapper.class, kind = Kind.ERROR, line = 30),
+            @Diagnostic(type = ErroneousMapper.class, kind = Kind.ERROR, line = 32)
         }
     )
-    public void shouldFailToGenerateMappingFromListToString() {
+    public void shouldFailToGenerateMappings() {
     }
 }

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

@@ -16,7 +16,7 @@
  *  See the License for the specific language governing permissions and
  *  limitations under the License.
  */
-package org.mapstruct.ap.test.erronuous;
+package org.mapstruct.ap.test.erroneous;
 
 public class Source {
 

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

@@ -16,7 +16,7 @@
  *  See the License for the specific language governing permissions and
  *  limitations under the License.
  */
-package org.mapstruct.ap.test.erronuous;
+package org.mapstruct.ap.test.erroneous;
 
 public class Target {