Verify @⁠MockitoSpyBean can spy bean from FactoryBean with generics

This commit introduces a test which verifies that @⁠MockitoSpyBean on a
field with generics can be used to replace an existing bean with
matching generics that's produced by a FactoryBean that's
programmatically registered via an ImportBeanDefinitionRegistrar.

However, the test is currently @⁠Disabled until the fix for
https://github.com/spring-projects/spring-boot/issues/40234 has been
ported to Spring Framework.

See gh-33742

spring-test/src/test/java/org/springframework/test/context/bean/override/mockito/integration/MockitoSpyBeanWithGenericsOnTestFieldForExistingGenericBeanIntegrationTests.java

@@ -40,6 +40,7 @@ import static org.mockito.BDDMockito.then;
  * @author Sam Brannen
  * @since 6.2
  * @see MockitoBeanWithGenericsOnTestFieldForNewBeanIntegrationTests
+ * @see MockitoSpyBeanWithGenericsOnTestFieldForExistingGenericBeanProducedByFactoryBeanIntegrationTests
  */
 @SpringJUnitConfig
 class MockitoSpyBeanWithGenericsOnTestFieldForExistingGenericBeanIntegrationTests {
@@ -60,7 +61,7 @@ class MockitoSpyBeanWithGenericsOnTestFieldForExistingGenericBeanIntegrationTest
 
 	@Configuration(proxyBeanMethods = false)
 	@Import({ ExampleGenericServiceCaller.class, IntegerExampleGenericService.class })
-	static class SpyBeanOnTestFieldForExistingBeanConfig {
+	static class Config {
 
 		@Bean
 		ExampleGenericService<String> simpleExampleStringGenericService() {
@@ -68,7 +69,6 @@ class MockitoSpyBeanWithGenericsOnTestFieldForExistingGenericBeanIntegrationTest
 			// generic type instead of the actual implementation class.
 			return new StringExampleGenericService("Enigma");
 		}
-
 	}
 
 }

spring-test/src/test/java/org/springframework/test/context/bean/override/mockito/integration/MockitoSpyBeanWithGenericsOnTestFieldForExistingGenericBeanProducedByFactoryBeanIntegrationTests.java

@@ -0,0 +1,101 @@
+/*
+ * Copyright 2012-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.test.context.bean.override.mockito.integration;
+
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+import org.mockito.MockingDetails;
+
+import org.springframework.beans.factory.FactoryBean;
+import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.beans.factory.support.RootBeanDefinition;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
+import org.springframework.core.ResolvableType;
+import org.springframework.core.type.AnnotationMetadata;
+import org.springframework.test.context.bean.override.example.ExampleGenericService;
+import org.springframework.test.context.bean.override.example.StringExampleGenericService;
+import org.springframework.test.context.bean.override.mockito.MockitoSpyBean;
+import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mockingDetails;
+
+/**
+ * Tests that {@link MockitoSpyBean @MockitoSpyBean} on a field with generics can
+ * be used to replace an existing bean with matching generics that's produced by a
+ * {@link FactoryBean} that's programmatically registered via an
+ * {@link ImportBeanDefinitionRegistrar}.
+ *
+ * @author Andy Wilkinson
+ * @author Sam Brannen
+ * @since 6.2
+ * @see MockitoSpyBeanWithGenericsOnTestFieldForExistingGenericBeanIntegrationTests
+ */
+@SpringJUnitConfig
+@Disabled("Disabled until https://github.com/spring-projects/spring-boot/issues/40234 is ported to Spring Framework")
+class MockitoSpyBeanWithGenericsOnTestFieldForExistingGenericBeanProducedByFactoryBeanIntegrationTests {
+
+	@MockitoSpyBean("exampleService")
+	ExampleGenericService<String> exampleService;
+
+
+	@Test
+	void testSpying() {
+		MockingDetails mockingDetails = mockingDetails(this.exampleService);
+		assertThat(mockingDetails.isSpy()).isTrue();
+		assertThat(mockingDetails.getMockCreationSettings().getSpiedInstance())
+				.isInstanceOf(StringExampleGenericService.class);
+	}
+
+
+	@Configuration(proxyBeanMethods = false)
+	@Import(FactoryBeanRegistrar.class)
+	static class Config {
+	}
+
+	static class FactoryBeanRegistrar implements ImportBeanDefinitionRegistrar {
+
+		@Override
+		public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata,
+				BeanDefinitionRegistry registry) {
+
+			RootBeanDefinition definition = new RootBeanDefinition(ExampleGenericServiceFactoryBean.class);
+			ResolvableType targetType = ResolvableType.forClassWithGenerics(
+					ExampleGenericServiceFactoryBean.class, null, ExampleGenericService.class);
+			definition.setTargetType(targetType);
+			registry.registerBeanDefinition("exampleService", definition);
+		}
+	}
+
+	static class ExampleGenericServiceFactoryBean<T, U extends ExampleGenericService<T>> implements FactoryBean<U> {
+
+		@Override
+		@SuppressWarnings("unchecked")
+		public U getObject() throws Exception {
+			return (U) new StringExampleGenericService("Enigma");
+		}
+
+		@Override
+		@SuppressWarnings("rawtypes")
+		public Class<ExampleGenericService> getObjectType() {
+			return ExampleGenericService.class;
+		}
+	}
+
+}