#2164 parameter matching should be done based on name when source name is absent (#2193)

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

@@ -1068,10 +1068,23 @@ public class BeanMappingMethod extends NormalTypeMappingMethod {
             // its a plain-old property mapping
             else  {
 
-                // determine source parameter
                 SourceReference sourceRef = mappingRef.getSourceReference();
+                // sourceRef is not defined, check if a source property has the same name
                 if ( sourceRef == null && method.getSourceParameters().size() == 1 ) {
-                    sourceRef = getSourceRef( method.getSourceParameters().get( 0 ), targetPropertyName );
+                    sourceRef = getSourceRefByTargetName( method.getSourceParameters().get( 0 ), targetPropertyName );
+                }
+
+                if ( sourceRef == null ) {
+                    // still no match. Try if one of the parameters has the same name
+                    sourceRef = method.getSourceParameters()
+                        .stream()
+                        .filter( p -> targetPropertyName.equals( p.getName() ) )
+                        .findAny()
+                        .map( p -> new SourceReference.BuilderFromProperty()
+                            .sourceParameter( p )
+                            .name( targetPropertyName )
+                            .build() )
+                        .orElse( null );
                 }
 
                 if ( sourceRef != null ) {
@@ -1153,7 +1166,7 @@ public class BeanMappingMethod extends NormalTypeMappingMethod {
             List<SourceReference> sourceReferences = new ArrayList<>();
             for ( String targetPropertyName : unprocessedTargetProperties.keySet() ) {
                 for ( Parameter sourceParameter : method.getSourceParameters() ) {
-                    SourceReference sourceRef = getSourceRef( sourceParameter, targetPropertyName );
+                    SourceReference sourceRef = getSourceRefByTargetName( sourceParameter, targetPropertyName );
                     if ( sourceRef != null ) {
                         sourceReferences.add( sourceRef );
                     }
@@ -1251,7 +1264,7 @@ public class BeanMappingMethod extends NormalTypeMappingMethod {
             }
         }
 
-        private SourceReference getSourceRef(Parameter sourceParameter, String targetPropertyName) {
+        private SourceReference getSourceRefByTargetName(Parameter sourceParameter, String targetPropertyName) {
 
             SourceReference sourceRef = null;
 
@@ -1261,11 +1274,11 @@ public class BeanMappingMethod extends NormalTypeMappingMethod {
 
             Accessor sourceReadAccessor =
                 sourceParameter.getType().getPropertyReadAccessors().get( targetPropertyName );
-
-            Accessor sourcePresenceChecker =
-                sourceParameter.getType().getPropertyPresenceCheckers().get( targetPropertyName );
-
             if ( sourceReadAccessor != null ) {
+                // property mapping
+                Accessor sourcePresenceChecker =
+                    sourceParameter.getType().getPropertyPresenceCheckers().get( targetPropertyName );
+
                 DeclaredType declaredSourceType = (DeclaredType) sourceParameter.getType().getTypeMirror();
                 Type returnType = ctx.getTypeFactory().getReturnType( declaredSourceType, sourceReadAccessor );
                 sourceRef = new SourceReference.BuilderFromProperty().sourceParameter( sourceParameter )

processor/src/test/java/org/mapstruct/ap/test/bugs/_2164/Issue2164Mapper.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.bugs._2164;
+
+import java.math.BigDecimal;
+
+import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
+import org.mapstruct.Named;
+import org.mapstruct.factory.Mappers;
+
+@Mapper
+public interface Issue2164Mapper {
+
+    Issue2164Mapper INSTANCE = Mappers.getMapper( Issue2164Mapper.class );
+
+    @Mapping(target = "value", qualifiedByName = "truncate2")
+    Target map(BigDecimal value);
+
+    @Named( "truncate2" )
+    default String truncate2(String in) {
+        return in.substring( 0, 2 );
+    }
+
+    class Target {
+
+        private String value;
+
+        public String getValue() {
+            return value;
+        }
+
+        public void setValue(String value) {
+            this.value = value;
+        }
+    }
+}

processor/src/test/java/org/mapstruct/ap/test/bugs/_2164/Issue2164Test.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.bugs._2164;
+
+import java.math.BigDecimal;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mapstruct.ap.testutil.IssueKey;
+import org.mapstruct.ap.testutil.WithClasses;
+import org.mapstruct.ap.testutil.runner.AnnotationProcessorTestRunner;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@IssueKey("2164")
+@WithClasses(Issue2164Mapper.class)
+@RunWith(AnnotationProcessorTestRunner.class)
+public class Issue2164Test {
+
+    @Test
+    public void shouldSelectProperMethod() {
+
+        Issue2164Mapper.Target target = Issue2164Mapper.INSTANCE.map( new BigDecimal( "1234" ) );
+
+        assertThat( target ).isNotNull();
+        assertThat( target.getValue() ).isEqualTo( "12" );
+    }
+}