Made possible to generate projections on java records (#164)

Co-authored-by: Marvin Froeder <[email protected]>

Author: velo

querydsl-apt/pom.xml

@@ -116,6 +116,12 @@
       <artifactId>ecj</artifactId>
       <scope>test</scope>
     </dependency>
+
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter</artifactId>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 
   <build>

querydsl-apt/src/main/java/com/querydsl/apt/AbstractQuerydslProcessor.java

@@ -315,12 +315,20 @@ private void registerTypeElement(String entityName, TypeElement element) {
   private void processProjectionTypes(Set<TypeElement> elements) {
     Set<Element> visited = new HashSet<Element>();
     for (Element element : getElements(QueryProjection.class)) {
-      Element parent = element.getEnclosingElement();
-      if (!elements.contains(parent) && !visited.contains(parent)) {
-        EntityType model = elementHandler.handleProjectionType((TypeElement) parent);
-        registerTypeElement(model.getFullName(), (TypeElement) parent);
+      if (element.getKind() == ElementKind.CONSTRUCTOR) {
+        Element parent = element.getEnclosingElement();
+        if (!elements.contains(parent) && !visited.contains(parent)) {
+          EntityType model = elementHandler.handleProjectionType((TypeElement) parent, true);
+          registerTypeElement(model.getFullName(), (TypeElement) parent);
+          context.projectionTypes.put(model.getFullName(), model);
+          visited.add(parent);
+        }
+      }
+      if (element.getKind().isClass() && !visited.contains(element)) {
+        EntityType model = elementHandler.handleProjectionType((TypeElement) element, false);
+        registerTypeElement(model.getFullName(), (TypeElement) element);
         context.projectionTypes.put(model.getFullName(), model);
-        visited.add(parent);
+        visited.add(element);
       }
     }
   }

querydsl-apt/src/main/java/com/querydsl/apt/Configuration.java

@@ -83,7 +83,7 @@ public interface Configuration {
 
   boolean isUseGetters();
 
-  boolean isValidConstructor(ExecutableElement constructor);
+  boolean isValidConstructor(ExecutableElement constructor, boolean onlyAnnotatedConstructors);
 
   boolean isValidField(VariableElement field);
 

querydsl-apt/src/main/java/com/querydsl/apt/DefaultConfiguration.java

@@ -469,9 +469,10 @@ public boolean isUseGetters() {
   }
 
   @Override
-  public boolean isValidConstructor(ExecutableElement constructor) {
+  public boolean isValidConstructor(
+      ExecutableElement constructor, boolean onlyAnnotatedConstructors) {
     return constructor.getModifiers().contains(Modifier.PUBLIC)
-        && constructor.getAnnotation(QueryProjection.class) != null
+        && (!onlyAnnotatedConstructors || constructor.getAnnotation(QueryProjection.class) != null)
         && !constructor.getParameters().isEmpty();
   }
 

querydsl-apt/src/main/java/com/querydsl/apt/TypeElementHandler.java

@@ -78,7 +78,7 @@ public EntityType handleEntityType(TypeElement element) {
 
     // constructors
     if (config.visitConstructors()) {
-      handleConstructors(entityType, elements);
+      handleConstructors(entityType, elements, true);
     }
 
     // fields
@@ -175,13 +175,13 @@ private Property toProperty(
     return new Property(entityType, name, propertyType, inits);
   }
 
-  public EntityType handleProjectionType(TypeElement e) {
+  public EntityType handleProjectionType(TypeElement e, boolean onlyAnnotatedConstructors) {
     Type c = typeFactory.getType(e.asType(), true);
     EntityType entityType =
         new EntityType(c.as(TypeCategory.ENTITY), configuration.getVariableNameFunction());
     typeMappings.register(entityType, queryTypeFactory.create(entityType));
     List<? extends Element> elements = e.getEnclosedElements();
-    handleConstructors(entityType, elements);
+    handleConstructors(entityType, elements, onlyAnnotatedConstructors);
     return entityType;
   }
 
@@ -197,9 +197,10 @@ private Type getType(VariableElement element) {
     return rv;
   }
 
-  private void handleConstructors(EntityType entityType, List<? extends Element> elements) {
+  private void handleConstructors(
+      EntityType entityType, List<? extends Element> elements, boolean onlyAnnotatedConstructors) {
     for (ExecutableElement constructor : ElementFilter.constructorsIn(elements)) {
-      if (configuration.isValidConstructor(constructor)) {
+      if (configuration.isValidConstructor(constructor, onlyAnnotatedConstructors)) {
         List<Parameter> parameters = transformParams(constructor.getParameters());
         entityType.addConstructor(new Constructor(parameters));
       }

querydsl-apt/src/test/java/com/querydsl/apt/GenericExporterTest.java

@@ -1,6 +1,6 @@
 package com.querydsl.apt;
 
-import static org.assertj.core.api.Assertions.fail;
+import static org.assertj.core.api.Assertions.assertThat;
 
 import com.querydsl.apt.domain.AbstractEntityTest;
 import com.querydsl.apt.domain.CustomCollection;
@@ -147,16 +147,8 @@ private void execute(List<String> expected, String genericExporterFolder, String
     expected.remove("QGeneric4Test_HidaBez.java"); // unstable
     expected.remove("QGeneric16Test_HidaBezGruppe.java"); // unstable
     expected.remove("QGeneric4Test_HidaBezGruppe.java"); // unstable
-    if (!expected.isEmpty()) {
-      fail("Following expected failures succeeded: " + expected);
-    }
 
-    if (!failures.isEmpty()) {
-      for (String failure : failures) {
-        System.err.println(failure);
-      }
-      fail(
-          "Failed with " + failures.size() + " failures, " + successes + " succeeded, " + failures);
-    }
+    assertThat(expected).isEmpty();
+    assertThat(failures).isEmpty();
   }
 }

querydsl-apt/src/test/java/com/querydsl/apt/domain/QueryProjectionTest.java

@@ -100,4 +100,15 @@ public void dto_case() throws SecurityException, NoSuchMethodException {
     new QQueryProjectionTest_DTOWithProjection(longExpr, stringExpr).newInstance(0L, "");
     new QQueryProjectionTest_DTOWithProjection(stringExpr, stringExpr).newInstance("", "");
   }
+
+  @QueryProjection
+  public static record RecordProjection(long param0, String param1) {}
+
+  @Test
+  public void record_case() throws SecurityException, NoSuchMethodException {
+    NumberExpression<Long> longExpr = Expressions.numberPath(Long.class, "x");
+    StringExpression stringExpr = Expressions.stringPath("x");
+
+    new QQueryProjectionTest_RecordProjection(longExpr, stringExpr).newInstance(0L, "");
+  }
 }

querydsl-core/src/main/java/com/querydsl/core/annotations/QueryProjection.java

@@ -51,6 +51,6 @@
  * }</pre>
  */
 @Documented
-@Target(ElementType.CONSTRUCTOR)
+@Target({ElementType.CONSTRUCTOR, ElementType.TYPE})
 @Retention(RUNTIME)
 public @interface QueryProjection {}