Inspection for Mapping to target = "." without source

src/main/java/org/mapstruct/intellij/inspection/MappingAnnotationInspectionBase.java

@@ -48,6 +48,9 @@ public void visitAnnotation(@NotNull PsiAnnotation annotation ) {
                             && annotationAttribute.getAttributeValue() != null) {
                         PsiNameValuePair nameValuePair = (PsiNameValuePair) annotationAttribute;
                         switch (nameValuePair.getAttributeName()) {
+                            case "target" :
+                                mappingAnnotation.setTargetProperty( nameValuePair );
+                                break;
                             case "source":
                                 mappingAnnotation.setSourceProperty( nameValuePair );
                                 break;
@@ -91,6 +94,7 @@ abstract void visitMappingAnnotation( @NotNull ProblemsHolder problemsHolder, @N
                                           @NotNull MappingAnnotation mappingAnnotation );
 
     protected static class MappingAnnotation {
+        private PsiNameValuePair targetProperty;
         private PsiNameValuePair sourceProperty;
         private PsiNameValuePair constantProperty;
         private PsiNameValuePair defaultValueProperty;
@@ -101,6 +105,18 @@ protected static class MappingAnnotation {
         private PsiNameValuePair qualifiedByNameProperty;
         private PsiNameValuePair conditionExpression;
 
+        public PsiNameValuePair getTargetProperty() {
+            return targetProperty;
+        }
+
+        public void setTargetProperty( PsiNameValuePair targetProperty ) {
+            this.targetProperty = targetProperty;
+        }
+
+        public boolean isNotThisTarget() {
+            return targetProperty == null || !".".equals( targetProperty.getLiteralValue() );
+        }
+
         public PsiNameValuePair getSourceProperty() {
             return sourceProperty;
         }

src/main/java/org/mapstruct/intellij/inspection/MoreThanOneSourcePropertyDefinedInspection.java

@@ -28,15 +28,16 @@ void visitMappingAnnotation( @NotNull ProblemsHolder problemsHolder, @NotNull Ps
             || (mappingAnnotation.getSourceProperty() != null && mappingAnnotation.getExpressionProperty() != null)) {
             ArrayList<LocalQuickFix> quickFixes = new ArrayList<>( 5 );
             String family = MapStructBundle.message( "intention.more.than.one.source.property" );
-            if (mappingAnnotation.getSourceProperty() != null) {
+            if (mappingAnnotation.getSourceProperty() != null && mappingAnnotation.isNotThisTarget()) {
                 quickFixes.add( createRemoveAnnotationAttributeQuickFix( mappingAnnotation.getSourceProperty(),
                         "Remove source value", family ) );
             }
             if (mappingAnnotation.getConstantProperty() != null) {
                 quickFixes.add( createRemoveAnnotationAttributeQuickFix( mappingAnnotation.getConstantProperty(),
                         "Remove constant value", family ) );
 
-                if (mappingAnnotation.hasNoDefaultProperties() && mappingAnnotation.getSourceProperty() != null) {
+                if (mappingAnnotation.hasNoDefaultProperties() && mappingAnnotation.getSourceProperty() != null
+                        && mappingAnnotation.isNotThisTarget() ) {
                     quickFixes.add( createReplaceAsDefaultValueQuickFix(
                             mappingAnnotation.getConstantProperty(), "constant", "defaultValue",
                             "Use constant value as default value", family ) );
@@ -45,7 +46,8 @@ void visitMappingAnnotation( @NotNull ProblemsHolder problemsHolder, @NotNull Ps
             if (mappingAnnotation.getExpressionProperty() != null) {
                 quickFixes.add( createRemoveAnnotationAttributeQuickFix( mappingAnnotation.getExpressionProperty(),
                         "Remove expression", family ) );
-                if (mappingAnnotation.hasNoDefaultProperties() && mappingAnnotation.getSourceProperty() != null) {
+                if (mappingAnnotation.hasNoDefaultProperties() && mappingAnnotation.getSourceProperty() != null
+                        && mappingAnnotation.isNotThisTarget() ) {
                     quickFixes.add( createReplaceAsDefaultValueQuickFix(
                             mappingAnnotation.getExpressionProperty(), "expression", "defaultExpression",
                             "Use expression as default expression", family ) );

src/main/java/org/mapstruct/intellij/inspection/TargetThisMappingNoSourcePropertyInspection.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at https://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.intellij.inspection;
+
+import com.intellij.codeInspection.ProblemsHolder;
+import com.intellij.psi.PsiAnnotation;
+import org.jetbrains.annotations.NotNull;
+import org.mapstruct.intellij.MapStructBundle;
+
+/**
+ * @author hduelme
+ */
+public class TargetThisMappingNoSourcePropertyInspection extends MappingAnnotationInspectionBase {
+
+    @Override
+    void visitMappingAnnotation(@NotNull ProblemsHolder problemsHolder, @NotNull PsiAnnotation psiAnnotation,
+                                @NotNull MappingAnnotation mappingAnnotation) {
+        if ( mappingAnnotation.isNotThisTarget() || mappingAnnotation.getIgnoreProperty() != null)  {
+            return;
+        }
+        if (mappingAnnotation.getSourceProperty() == null ) {
+            problemsHolder.registerProblem( psiAnnotation,
+                    MapStructBundle.message( "inspection.this.target.mapping.no.source.property" ) );
+        }
+    }
+}

src/main/resources/META-INF/plugin.xml

@@ -120,6 +120,14 @@
             key="inspection.wrong.map.mapping.map.type"
             shortName="FromMapMappingInspection"
             implementationClass="org.mapstruct.intellij.inspection.FromMapMappingMapTypeInspection"/>
+    <localInspection
+            language="JAVA"
+            enabledByDefault="true"
+            level="ERROR"
+            bundle="org.mapstruct.intellij.messages.MapStructBundle"
+            key="inspection.this.target.mapping.no.source.property"
+            shortName="TargetThisMappingNoSourcePropertyInspection"
+            implementationClass="org.mapstruct.intellij.inspection.TargetThisMappingNoSourcePropertyInspection"/>
   </extensions>
 
   <actions>

src/main/resources/inspectionDescriptions/TargetThisMappingNoSourcePropertyInspection.html

@@ -0,0 +1,28 @@
+<html>
+<body>
+<p>
+    This inspection reports when <code> @Mapping( target = ".") </code> is used without a source property.
+</p>
+<p>
+<pre><code>
+//wrong
+@Mapper
+public interface EmployeeMapper {
+    @Mapping(target = ".", expression = "java(company.getEmployee())"
+    Employee toEmployee(Company company, @Context CycleAvoidingMappingContext context);
+}
+</code></pre>
+</p>
+<p>
+<pre><code>
+//correct
+@Mapper
+public interface EmployeeMapper {
+    @Mapping(target = ".", source = "employee")
+    Employee toEmployee(Company company, @Context CycleAvoidingMappingContext context);
+}
+</code></pre>
+</p>
+<!-- tooltip end -->
+</body>
+</html>

src/main/resources/org/mapstruct/intellij/messages/MapStructBundle.properties

@@ -19,6 +19,7 @@ inspection.not.null.checkable.property.source.used.with.default.property.title=C
 inspection.java.expression.unnecessary.whitespace=Unnecessary whitespaces {0} {1}
 inspection.java.expression.remove.unnecessary.whitespace=Remove unnecessary whitespaces {0} {1}
 inspection.java.expression.unnecessary.whitespace.title=Unnecessary whitespaces before or after Java expression
+inspection.this.target.mapping.no.source.property=Using @Mapping( target = ".") requires a source property. Expression or constant cannot be used as a source
 inspection.wrong.map.mapping.map.type=Map type is raw or key type is not string for mapping Map to Bean
 inspection.wrong.map.mapping.map.type.raw=Raw map used for mapping Map to Bean
 inspection.wrong.map.mapping.map.type.raw.set.default=Replace {0} with {0}<String, String>

src/test/java/org/mapstruct/intellij/inspection/MoreThanOneSourcePropertyDefinedInspectionTest.java

@@ -40,6 +40,21 @@ public void testMoreThanOneSourceConstantAndSource() {
         myFixture.checkResultByFile( testName + "_after.java" );
     }
 
+    public void testMoreThanOneSourceConstantAndSourceThisMapping() {
+        doTest();
+        List<IntentionAction> allQuickFixes = myFixture.getAllQuickFixes();
+        assertThat( allQuickFixes )
+                .extracting( IntentionAction::getText )
+                .as( "Intent Text" )
+                .containsExactly(
+                        "Remove constant value",
+                        "Remove constant value"
+                );
+        allQuickFixes.forEach( myFixture::launchAction );
+        String testName = getTestName( false );
+        myFixture.checkResultByFile( testName + "_after.java" );
+    }
+
     public void testMoreThanOneSourceConstantAndExpression() {
         doTest();
         List<IntentionAction> allQuickFixes = myFixture.getAllQuickFixes();
@@ -74,4 +89,19 @@ public void testMoreThanOneSourceExpressionAndSource() {
         String testName = getTestName( false );
         myFixture.checkResultByFile( testName + "_after.java" );
     }
+
+    public void testMoreThanOneSourceExpressionAndSourceThisMapping() {
+        doTest();
+        List<IntentionAction> allQuickFixes = myFixture.getAllQuickFixes();
+        assertThat( allQuickFixes )
+                .extracting( IntentionAction::getText )
+                .as( "Intent Text" )
+                .containsExactly(
+                        "Remove expression",
+                        "Remove expression"
+                );
+        allQuickFixes.forEach( myFixture::launchAction );
+        String testName = getTestName( false );
+        myFixture.checkResultByFile( testName + "_after.java" );
+    }
 }

src/test/java/org/mapstruct/intellij/inspection/TargetThisMappingNoSourcePropertyInspectionTest.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at https://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.intellij.inspection;
+
+import com.intellij.codeInspection.LocalInspectionTool;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * @author hduelme
+ */
+public class TargetThisMappingNoSourcePropertyInspectionTest extends BaseInspectionTest {
+    @Override
+    protected @NotNull Class<? extends LocalInspectionTool> getInspection() {
+        return TargetThisMappingNoSourcePropertyInspection.class;
+    }
+
+    public void testTargetThisMappingNoSourceProperty() {
+        doTest();
+    }
+}

testData/inspection/MoreThanOneSourceConstantAndSourceThisMapping.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at https://www.apache.org/licenses/LICENSE-2.0
+ */
+
+import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
+import org.mapstruct.Mappings;
+
+class Source {
+
+    private Target innerTarget;
+
+    public Target getInnerTarget() {
+        return innerTarget;
+    }
+
+    public void setInnerTarget(Target innerTarget) {
+        this.innerTarget = innerTarget;
+    }
+}
+
+class Target {
+
+    private String testName;
+
+    public String getTestName() {
+        return testName;
+    }
+
+    public void setTestName(String testName) {
+        this.testName = testName;
+    }
+}
+
+@Mapper
+interface SingleMappingMapper {
+
+    <error descr="More than one source property defined">@Mapping(target = ".", source = "innerTarget", constant = "My name")</error>
+    Target map(Source source);
+}
+
+@Mapper
+interface SingleMappingsMapper {
+
+    @Mappings({
+            <error descr="More than one source property defined">@Mapping(target = ".", source = "innerTarget", constant = "My name")</error>
+            })
+    Target map(Source source);
+}
+

testData/inspection/MoreThanOneSourceConstantAndSourceThisMapping_after.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at https://www.apache.org/licenses/LICENSE-2.0
+ */
+
+import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
+import org.mapstruct.Mappings;
+
+class Source {
+
+    private Target innerTarget;
+
+    public Target getInnerTarget() {
+        return innerTarget;
+    }
+
+    public void setInnerTarget(Target innerTarget) {
+        this.innerTarget = innerTarget;
+    }
+}
+
+class Target {
+
+    private String testName;
+
+    public String getTestName() {
+        return testName;
+    }
+
+    public void setTestName(String testName) {
+        this.testName = testName;
+    }
+}
+
+@Mapper
+interface SingleMappingMapper {
+
+    @Mapping(target = ".", source = "innerTarget")
+    Target map(Source source);
+}
+
+@Mapper
+interface SingleMappingsMapper {
+
+    @Mappings({
+            @Mapping(target = ".", source = "innerTarget")
+            })
+    Target map(Source source);
+}
+

testData/inspection/MoreThanOneSourceExpressionAndSourceThisMapping.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at https://www.apache.org/licenses/LICENSE-2.0
+ */
+
+import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
+import org.mapstruct.Mappings;
+
+class Source {
+
+    private Target innerTarget;
+
+    public Target getInnerTarget() {
+        return innerTarget;
+    }
+
+    public void setInnerTarget(Target innerTarget) {
+        this.innerTarget = innerTarget;
+    }
+}
+
+class Target {
+
+    private String testName;
+
+    public String getTestName() {
+        return testName;
+    }
+
+    public void setTestName(String testName) {
+        this.testName = testName;
+    }
+}
+
+@Mapper
+interface SingleMappingMapper {
+
+    <error descr="More than one source property defined">@Mapping(target = ".", source = "innerTarget", expression = "java()")</error>
+    Target map(Source source);
+}
+
+@Mapper
+interface SingleMappingsMapper {
+
+    @Mappings({
+            <error descr="More than one source property defined">@Mapping(target = ".", source = "innerTarget", expression = "java()")</error>
+            })
+    Target map(Source source);
+}
+