Avoid ClassCastException in JavaExpressionInjector

filiphr · filiphr · commit c1d15815e824 · 2020-07-04T19:02:37.000+02:00
Fixes #52
diff --git a/change-notes.html b/change-notes.html
@@ -1,5 +1,9 @@
 <html>
 <h2>1.2.1</h2>
+<h2>1.2.2</h2>
+<ul>
+    <li>Bug fix: ClassCastException in language injection in expressions</li>
+</ul>
 <ul>
     <li>Support code completion in Mapping#expression and Mapping#defaultExpression</li>
     <li>Support meta annotations for when looking for unmapped target properties</li>
diff --git a/src/main/java/org/mapstruct/intellij/expression/JavaExpressionInjector.java b/src/main/java/org/mapstruct/intellij/expression/JavaExpressionInjector.java
@@ -31,6 +31,7 @@
 import com.intellij.psi.PsiReference;
 import com.intellij.psi.PsiType;
 import com.intellij.psi.impl.source.resolve.reference.ReferenceProvidersRegistry;
+import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.psi.util.PsiUtil;
 import org.jetbrains.annotations.NotNull;
 import org.mapstruct.intellij.util.MapstructElementUtils;
@@ -64,8 +65,13 @@ public void getLanguagesToInject(@NotNull MultiHostRegistrar registrar, @NotNull
             // PsiModifierList
             // PsiMethod
 
-            PsiAnnotationParameterList annotationParameterList = (PsiAnnotationParameterList) context.getParent()
-                .getParent();
+            PsiAnnotationParameterList annotationParameterList = PsiTreeUtil.getParentOfType(
+                context,
+                PsiAnnotationParameterList.class
+            );
+            if ( annotationParameterList == null ) {
+                return;
+            }
             PsiType targetType = null;
             for ( PsiNameValuePair attribute : annotationParameterList.getAttributes() ) {
                 if ( "target" .equals( attribute.getAttributeName() ) ) {
@@ -91,8 +97,15 @@ else if ( resolved instanceof PsiParameter ) {
                 return;
             }
 
-            PsiMethod method = (PsiMethod) annotationParameterList.getParent().getParent().getParent();
-            PsiClass mapperClass = (PsiClass) method.getParent();
+            PsiMethod method = PsiTreeUtil.getParentOfType( annotationParameterList, PsiMethod.class );;
+            if ( method == null ) {
+                return;
+            }
+
+            PsiClass mapperClass = PsiTreeUtil.getParentOfType( method, PsiClass.class );
+            if ( mapperClass == null ) {
+                return;
+            }
             StringBuilder importsBuilder = new StringBuilder();
             StringBuilder prefixBuilder = new StringBuilder();
 
diff --git a/src/test/java/org/mapstruct/intellij/expression/JavaExpressionInjectionTest.java b/src/test/java/org/mapstruct/intellij/expression/JavaExpressionInjectionTest.java
@@ -28,6 +28,7 @@ public class JavaExpressionInjectionTest extends MapstructBaseCompletionTestCase
         "\n" +
         "import org.mapstruct.Mapper;\n" +
         "import org.mapstruct.Mapping;\n" +
+        "import org.mapstruct.Mappings;\n" +
         "import org.example.dto.CarDto;\n" +
         "import org.example.dto.Car;\n" +
         "\n" +
@@ -126,6 +127,43 @@ protected void withTargetDefinedMapper(String attribute) {
         assertThat( elementAt.getText() ).isEqualTo( ";" );
     }
 
+    public void testExpressionWithTargetDefinedMapperInMappings() {
+        withTargetDefinedMapperInMappings( "expression" );
+        withTargetDefinedMapperInMappings( "defaultExpression" );
+    }
+
+    protected void withTargetDefinedMapperInMappings(String attribute) {
+        String mapping = "@Mappings(\n" +
+            "@Mapping(target = \"manufacturingYear\", " + attribute + " = \"java(car.<caret>)\")\n" +
+            ")\n";
+        @Language("java")
+        String mapper = String.format( CAR_MAPPER, "", mapping );
+        PsiFile file = configureMapperByText( mapper );
+
+        assertThat( myFixture.completeBasic() )
+            .extracting( LookupElementPresentation::renderElement )
+            .extracting( LookupElementPresentation::getItemText )
+            .contains(
+                "getMake",
+                "setMake",
+                "getManufacturingDate",
+                "setManufacturingDate",
+                "getNumberOfSeats",
+                "setNumberOfSeats"
+            );
+
+        assertThat( myFixture.complete( CompletionType.SMART ) )
+            .extracting( LookupElementPresentation::renderElement )
+            .extracting( LookupElementPresentation::getItemText )
+            .containsExactlyInAnyOrder( "getMake", "toString" );
+
+        PsiElement elementAt = file.findElementAt( myFixture.getCaretOffset() );
+        assertThat( elementAt )
+            .isNotNull()
+            .isInstanceOf( PsiJavaToken.class );
+        assertThat( elementAt.getText() ).isEqualTo( ";" );
+    }
+
     public void testExpressionWithMapperWithImports() {
         withMapperWithImports( "expression" );
         withMapperWithImports( "defaultExpression" );
