Support advanced generics redeclarations in RepositoryFactoryBeanSupp…

…ort extensions.

Spring Data modules might override, and, by that, fix some of the generic type parameters exposed by RepositoryFactoryBeanSupport. We now more thoroughly walk through them to consider the ones expanded already and automatically expand the remaining ones with either the types found on the user repository interface or the unresolved type variable.

Ticket: GH-3074.

src/main/java/org/springframework/data/repository/config/RepositoryConfigurationDelegate.java

@@ -49,6 +49,7 @@
 import org.springframework.core.metrics.StartupStep;
 import org.springframework.data.repository.core.RepositoryMetadata;
 import org.springframework.data.repository.core.support.AbstractRepositoryMetadata;
+import org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport;
 import org.springframework.data.repository.core.support.RepositoryFactorySupport;
 import org.springframework.data.util.ReflectionUtils;
 import org.springframework.lang.Nullable;
@@ -339,22 +340,30 @@ private ResolvableType getRepositoryInterface(RepositoryConfiguration<?> configu
 			return null;
 		}
 
-		TypeVariable<?>[] variables = factoryBean.getTypeParameters();
-		int numberOfGenerics = variables.length;
 		RepositoryMetadata metadata = AbstractRepositoryMetadata.getMetadata(repositoryInterface);
+		List<Class<?>> types = List.of(repositoryInterface, metadata.getDomainType(), metadata.getIdType());
 
-		ResolvableType[] generics = new ResolvableType[numberOfGenerics];
-		generics[0] = ResolvableType.forClass(repositoryInterface);
-		generics[1] = ResolvableType.forClass(metadata.getDomainType());
-		generics[2] = ResolvableType.forClass(metadata.getIdType());
+		ResolvableType[] declaredGenerics = ResolvableType.forClass(factoryBean).getGenerics();
+		ResolvableType[] parentGenerics = ResolvableType.forClass(RepositoryFactoryBeanSupport.class, factoryBean)
+				.getGenerics();
+		List<ResolvableType> resolvedGenerics = new ArrayList<ResolvableType>(factoryBean.getTypeParameters().length);
 
-		if (numberOfGenerics > 3) {
-			for (int i = 3; i < numberOfGenerics; i++) {
-				generics[i] = ResolvableType.forType(variables[0]);
+		for (int i = 0; i < parentGenerics.length; i++) {
+
+			ResolvableType parameter = parentGenerics[i];
+
+			if (parameter.getType() instanceof TypeVariable<?>) {
+				resolvedGenerics.add(i < types.size() ? ResolvableType.forClass(types.get(i)) : parameter);
+			}
+		}
+
+		if (resolvedGenerics.size() < declaredGenerics.length) {
+			for (int j = parentGenerics.length; j < declaredGenerics.length; j++) {
+				resolvedGenerics.add(declaredGenerics[j]);
 			}
 		}
 
-		return ResolvableType.forClassWithGenerics(factoryBean, generics);
+		return ResolvableType.forClassWithGenerics(factoryBean, resolvedGenerics.toArray(ResolvableType[]::new));
 	}
 
 	/**

src/test/java/org/springframework/data/repository/config/RepositoryConfigurationDelegateUnitTests.java

@@ -17,6 +17,11 @@
 
 import static org.assertj.core.api.Assertions.*;
 
+import java.lang.reflect.TypeVariable;
+import java.util.List;
+import java.util.Optional;
+import java.util.UUID;
+
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mockito;
@@ -26,24 +31,30 @@
 import org.springframework.aop.framework.Advised;
 import org.springframework.aot.hint.RuntimeHints;
 import org.springframework.beans.factory.ListableBeanFactory;
+import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.parsing.BeanComponentDefinition;
 import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.context.annotation.AnnotationBeanNameGenerator;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.annotation.ComponentScan;
 import org.springframework.context.annotation.ComponentScan.Filter;
 import org.springframework.context.annotation.FilterType;
 import org.springframework.context.support.GenericApplicationContext;
+import org.springframework.core.ResolvableType;
 import org.springframework.core.env.StandardEnvironment;
 import org.springframework.core.metrics.ApplicationStartup;
 import org.springframework.core.type.AnnotationMetadata;
 import org.springframework.core.type.StandardAnnotationMetadata;
+import org.springframework.data.mapping.Person;
+import org.springframework.data.repository.Repository;
 import org.springframework.data.repository.config.RepositoryConfigurationDelegate.LazyRepositoryInjectionPointResolver;
 import org.springframework.data.repository.config.annotated.MyAnnotatedRepository;
 import org.springframework.data.repository.config.annotated.MyAnnotatedRepositoryImpl;
 import org.springframework.data.repository.config.annotated.MyFragmentImpl;
 import org.springframework.data.repository.config.excluded.MyOtherRepositoryImpl;
 import org.springframework.data.repository.config.stereotype.MyStereotypeRepository;
 import org.springframework.data.repository.core.support.DummyRepositoryFactoryBean;
+import org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport;
 import org.springframework.data.repository.sample.AddressRepository;
 import org.springframework.data.repository.sample.AddressRepositoryClient;
 import org.springframework.data.repository.sample.ProductRepository;
@@ -223,6 +234,38 @@ void registersAotPostProcessorForDifferentConfigurations() {
 		assertThat(context.getBeanNamesForType(RepositoryRegistrationAotProcessor.class)).hasSize(2);
 	}
 
+	@Test // GH-3074
+	void registersGenericsForIdConstrainingRepositoryFactoryBean() {
+
+		ResolvableType it = registerBeanDefinition(IdConstrainingRepositoryFactoryBean.class);
+
+		assertThat(it.getGenerics()).hasSize(2);
+		assertThat(it.getGeneric(0).resolve()).isEqualTo(MyAnnotatedRepository.class);
+		assertThat(it.getGeneric(1).resolve()).isEqualTo(Person.class);
+	}
+
+	@Test // GH-3074
+	void registersGenericsForDomainTypeConstrainingRepositoryFactoryBean() {
+
+		ResolvableType it = registerBeanDefinition(DomainTypeConstrainingRepositoryFactoryBean.class);
+
+		assertThat(it.getGenerics()).hasSize(2);
+		assertThat(it.getGeneric(0).resolve()).isEqualTo(MyAnnotatedRepository.class);
+		assertThat(it.getGeneric(1).resolve()).isEqualTo(String.class);
+	}
+
+	@Test // GH-3074
+	void registersGenericsForAdditionalGenericsRepositoryFactoryBean() {
+
+		ResolvableType it = registerBeanDefinition(AdditionalGenericsRepositoryFactoryBean.class);
+
+		assertThat(it.getGenerics()).hasSize(4);
+		assertThat(it.getGeneric(0).resolve()).isEqualTo(MyAnnotatedRepository.class);
+		assertThat(it.getGeneric(1).resolve()).isEqualTo(Person.class);
+		assertThat(it.getGeneric(2).resolve()).isEqualTo(String.class);
+		assertThat(it.getGeneric(3).getType()).isInstanceOf(TypeVariable.class);
+	}
+
 	private static ListableBeanFactory assertLazyRepositoryBeanSetup(Class<?> configClass) {
 
 		var context = new AnnotationConfigApplicationContext(configClass);
@@ -279,4 +322,56 @@ protected String getModulePrefix() {
 			return "commons";
 		}
 	}
+
+	private ResolvableType registerBeanDefinition(Class<?> repositoryFactoryType) {
+
+		AnnotationMetadata metadata = AnnotationMetadata.introspect(AnnotatedBeanNamesConfig.class);
+		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
+
+		RepositoryConfigurationSource source = new AnnotationRepositoryConfigurationSource(metadata,
+				EnableRepositories.class, context, context.getEnvironment(),
+				context.getDefaultListableBeanFactory(), new AnnotationBeanNameGenerator()) {
+
+			@Override
+			public Optional<String> getRepositoryFactoryBeanClassName() {
+				return Optional.of(repositoryFactoryType.getName());
+			}
+		};
+
+		RepositoryConfigurationDelegate delegate = new RepositoryConfigurationDelegate(source, context,
+				context.getEnvironment());
+
+		List<BeanComponentDefinition> repositories = delegate.registerRepositoriesIn(context, extension);
+
+		assertThat(repositories).hasSize(1).element(0)
+				.extracting(BeanComponentDefinition::getBeanDefinition)
+				.extracting(BeanDefinition::getResolvableType)
+				.isNotNull();
+
+		return repositories.get(0).getBeanDefinition().getResolvableType();
+	}
+
+	static abstract class IdConstrainingRepositoryFactoryBean<T extends Repository<S, UUID>, S>
+			extends RepositoryFactoryBeanSupport<T, S, UUID> {
+
+		protected IdConstrainingRepositoryFactoryBean(Class<? extends T> repositoryInterface) {
+			super(repositoryInterface);
+		}
+	}
+
+	static abstract class DomainTypeConstrainingRepositoryFactoryBean<T extends Repository<Person, ID>, ID>
+			extends RepositoryFactoryBeanSupport<T, Person, ID> {
+
+		protected DomainTypeConstrainingRepositoryFactoryBean(Class<? extends T> repositoryInterface) {
+			super(repositoryInterface);
+		}
+	}
+
+	static abstract class AdditionalGenericsRepositoryFactoryBean<T extends Repository<S, ID>, S, ID, R>
+			extends RepositoryFactoryBeanSupport<T, S, ID> {
+
+		protected AdditionalGenericsRepositoryFactoryBean(Class<? extends T> repositoryInterface) {
+			super(repositoryInterface);
+		}
+	}
 }