Add an ability to introspect builders

sourcegen-annotations/src/main/java/io/micronaut/sourcegen/annotations/Builder.java

@@ -32,4 +32,13 @@
 @Retention(RUNTIME)
 @Target({ElementType.ANNOTATION_TYPE, ElementType.TYPE})
 public @interface Builder {
+
+    /**
+     * If true, an {@link io.micronaut.core.annotation.Introspected} annotation will be added
+     * on the builder so that introspection can be created for it.
+     *
+     * @return Whether the builder needs to be introspected
+     */
+    boolean introspected() default true;
+
 }

sourcegen-annotations/src/main/java/io/micronaut/sourcegen/annotations/SuperBuilder.java

@@ -33,4 +33,13 @@
 @Retention(RUNTIME)
 @Target({ElementType.ANNOTATION_TYPE, ElementType.TYPE})
 public @interface SuperBuilder {
+
+    /**
+     * If true, an {@link io.micronaut.core.annotation.Introspected} annotation will be added
+     * on the builder so that introspection can be created for it.
+     *
+     * @return Whether the builder needs to be introspected
+     */
+    boolean introspected() default true;
+
 }

sourcegen-generator/src/main/java/io/micronaut/sourcegen/generator/visitors/BuilderAnnotationVisitor.java

@@ -15,7 +15,9 @@
  */
 package io.micronaut.sourcegen.generator.visitors;
 
+import io.micronaut.core.annotation.Creator;
 import io.micronaut.core.annotation.Internal;
+import io.micronaut.core.annotation.Introspected;
 import io.micronaut.core.annotation.NonNull;
 import io.micronaut.core.annotation.Nullable;
 import io.micronaut.core.bind.annotation.Bindable;
@@ -71,6 +73,8 @@
 @Internal
 public final class BuilderAnnotationVisitor implements TypeElementVisitor<Builder, Object> {
 
+    public static final String BUILDER_INTROSPECTED_MEMBER = "introspected";
+
     private final Set<String> processed = new HashSet<>();
 
     @Override
@@ -101,6 +105,9 @@ public void visitClass(ClassElement element, VisitorContext context) {
 
             ClassDef.ClassDefBuilder builder = ClassDef.builder(builderClassName)
                 .addModifiers(Modifier.PUBLIC, Modifier.FINAL);
+            if (element.booleanValue(Builder.class, BUILDER_INTROSPECTED_MEMBER).orElse(true)) {
+                builder.addAnnotation(Introspected.class);
+            }
 
             List<PropertyElement> properties = element.getBeanProperties();
             for (PropertyElement beanProperty : properties) {
@@ -151,7 +158,8 @@ public void visitClass(ClassElement element, VisitorContext context) {
     }
 
     private MethodDef createAllPropertiesConstructor(ClassTypeDef builderType, List<PropertyElement> properties) {
-        MethodDef.MethodDefBuilder builder = MethodDef.constructor();
+        MethodDef.MethodDefBuilder builder = MethodDef.constructor()
+            .addAnnotation(Creator.class);
         VariableDef.This self = new VariableDef.This(builderType);
         for (PropertyElement parameter : properties) {
             ParameterDef parameterDef = ParameterDef.of(parameter.getName(), TypeDef.of(parameter.getType()));

sourcegen-generator/src/main/java/io/micronaut/sourcegen/generator/visitors/SuperBuilderAnnotationVisitor.java

@@ -16,6 +16,7 @@
 package io.micronaut.sourcegen.generator.visitors;
 
 import io.micronaut.core.annotation.Internal;
+import io.micronaut.core.annotation.Introspected;
 import io.micronaut.core.annotation.NonNull;
 import io.micronaut.inject.ast.ClassElement;
 import io.micronaut.inject.ast.PropertyElement;
@@ -25,6 +26,7 @@
 import io.micronaut.sourcegen.annotations.SuperBuilder;
 import io.micronaut.sourcegen.generator.SourceGenerator;
 import io.micronaut.sourcegen.generator.SourceGenerators;
+import io.micronaut.sourcegen.model.AnnotationDef;
 import io.micronaut.sourcegen.model.ClassDef;
 import io.micronaut.sourcegen.model.ClassTypeDef;
 import io.micronaut.sourcegen.model.MethodDef;
@@ -46,6 +48,8 @@
 @Internal
 public final class SuperBuilderAnnotationVisitor implements TypeElementVisitor<SuperBuilder, Object> {
 
+    public static final String SUPER_BUILDER_INTROSPECTED_MEMBER = "introspected";
+
     private final Set<String> processed = new HashSet<>();
 
     @Override
@@ -148,6 +152,10 @@ public void visitClass(ClassElement element, VisitorContext context) {
                             )
                         )
                     );
+                if (element.booleanValue(SuperBuilder.class, SUPER_BUILDER_INTROSPECTED_MEMBER).orElse(true)) {
+                    builder.addAnnotation(AnnotationDef.builder(Introspected.class)
+                        .addMember("withPrefix", "").build());
+                }
 
                 builder.addMethod(createSelfMethod());
                 builder.addMethod(BuilderAnnotationVisitor.createBuildMethod(element));

test-suite-java/src/test/java/io/micronaut/sourcegen/example/AnimalSuperBuilderTest.java

@@ -16,9 +16,12 @@
 package io.micronaut.sourcegen.example;
 
 import java.lang.reflect.Modifier;
+
+import io.micronaut.core.beans.BeanIntrospection;
 import org.junit.jupiter.api.Test;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 class AnimalSuperBuilderTest {
@@ -61,6 +64,13 @@ public void testDog() {
     }
 //end::test[]
 
+    @Test
+    public void dogIntrospection() {
+        var introspection = BeanIntrospection.getIntrospection(DogSuperBuilder.class);
+        assertNotNull(introspection);
+        assertEquals(6, introspection.getBeanProperties().size());
+    }
+
     @Test
     public void internalTest() {
         assertTrue(Modifier.isPublic(CatSuperBuilder.class.getModifiers()));

test-suite-java/src/test/java/io/micronaut/sourcegen/example/PersonBuilderTest.java

@@ -15,10 +15,12 @@
  */
 package io.micronaut.sourcegen.example;
 
+import io.micronaut.core.beans.BeanIntrospection;
 import org.junit.jupiter.api.Test;
 
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
 
 class PersonBuilderTest {
 
@@ -36,6 +38,14 @@ public void buildsPerson() {
     }
 //end::test[]
 
+    @Test
+    public void personIntrospection() {
+        var introspection = BeanIntrospection.getIntrospection(PersonBuilder.class);
+        assertNotNull(introspection);
+        assertEquals(0, introspection.getBeanProperties().size());
+        assertEquals(3, introspection.getConstructorArguments().length);
+    }
+
     @Test
     public void buildsPersonWithPrimitiveDefaults() {
         var person = Person2Builder.builder()