#3413 Using Mapping#expression and Mapping#conditionaQualifiedBy(Name) should lead to compile error

copyright.txt

@@ -42,6 +42,7 @@ Kevin Grüneberg - https://github.com/kevcodez
 Lukas Lazar - https://github.com/LukeLaz
 Nikolas Charalambidis - https://github.com/Nikolas-Charalambidis
 Michael Pardo - https://github.com/pardom
+Muhammad Usama - https://github.com/the-mgi
 Mustafa Caylak - https://github.com/luxmeter
 Oliver Ehrenmüller - https://github.com/greuelpirat
 Oliver Erhart - https://github.com/thunderhook

processor/src/main/java/org/mapstruct/ap/internal/model/source/MappingOptions.java

@@ -207,10 +207,13 @@ public class MappingOptions extends DelegatingOptions {
         if ( gem.source().hasValue() && gem.constant().hasValue() ) {
             message = Message.PROPERTYMAPPING_SOURCE_AND_CONSTANT_BOTH_DEFINED;
         }
+        else if ( gem.expression().hasValue() && gem.conditionQualifiedByName().hasValue() ) {
+            message = Message.PROPERTYMAPPING_EXPRESSION_AND_CONDITION_QUALIFIED_BY_NAME_BOTH_DEFINED;
+        }
         else if ( gem.source().hasValue() && gem.expression().hasValue() ) {
             message = Message.PROPERTYMAPPING_SOURCE_AND_EXPRESSION_BOTH_DEFINED;
         }
-        else if (gem.expression().hasValue() && gem.constant().hasValue() ) {
+        else if ( gem.expression().hasValue() && gem.constant().hasValue() ) {
             message = Message.PROPERTYMAPPING_EXPRESSION_AND_CONSTANT_BOTH_DEFINED;
         }
         else if ( gem.expression().hasValue() && gem.defaultValue().hasValue() ) {

processor/src/main/java/org/mapstruct/ap/internal/util/Message.java

@@ -84,6 +84,7 @@ public enum Message {
     PROPERTYMAPPING_CANNOT_DETERMINE_SOURCE_PROPERTY_FROM_TARGET("The type of parameter \"%s\" has no property named \"%s\". Please define the source property explicitly."),
     PROPERTYMAPPING_CANNOT_DETERMINE_SOURCE_PARAMETER_FROM_TARGET("No property named \"%s\" exists in source parameter(s). Please define the source explicitly."),
     PROPERTYMAPPING_NO_SUITABLE_COLLECTION_OR_MAP_CONSTRUCTOR( "%s does not have an accessible copy or no-args constructor." ),
+    PROPERTYMAPPING_EXPRESSION_AND_CONDITION_QUALIFIED_BY_NAME_BOTH_DEFINED( "Expression and condition qualified by name are both defined in @Mapping, either define an expression or a condition qualified by name." ),
 
     CONVERSION_LOSSY_WARNING( "%s has a possibly lossy conversion from %s to %s.", Diagnostic.Kind.WARNING ),
     CONVERSION_LOSSY_ERROR( "Can't map %s. It has a possibly lossy conversion from %s to %s." ),

processor/src/test/java/org/mapstruct/ap/test/bugs/_3413/Erroneous3413Mapper.java

@@ -0,0 +1,45 @@
+/*
+ * 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._3413;
+
+import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
+import org.mapstruct.factory.Mappers;
+
+/**
+ * @author Muhammad Usama
+ */
+@Mapper
+public interface Erroneous3413Mapper {
+    Erroneous3413Mapper INSTANCE = Mappers.getMapper( Erroneous3413Mapper.class );
+
+    @Mapping(target = "", expression = "", conditionQualifiedByName = "")
+    ToPOJO map(FromPOJO fromPOJO);
+
+    class FromPOJO {
+        private String value;
+
+        public String getValue() {
+            return value;
+        }
+
+        public void setValue(String value) {
+            this.value = value;
+        }
+    }
+
+    class ToPOJO {
+        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/_3413/Issue3413Test.java

@@ -0,0 +1,35 @@
+/*
+ * 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._3413;
+
+import org.mapstruct.ap.testutil.IssueKey;
+import org.mapstruct.ap.testutil.ProcessorTest;
+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;
+
+/**
+ * @author Muhammad Usama
+ */
+@IssueKey("3413")
+public class Issue3413Test {
+    @ProcessorTest
+    @WithClasses(Erroneous3413Mapper.class)
+    @ExpectedCompilationOutcome(
+        value = CompilationResult.FAILED,
+        diagnostics = {
+            @Diagnostic(
+                kind = javax.tools.Diagnostic.Kind.ERROR,
+                line = 19,
+                message = "Expression and condition qualified by name are both defined in @Mapping, " +
+                    "either define an expression or a condition qualified by name."
+            )
+        }
+    )
+    void errorExpectedBecauseExpressionAndConditionQualifiedByNameCannotCoExists() {
+    }
+}