Add generics to BeanInstanceSupplier

Update `BeanInstanceSupplier` to support a generic type.

See gh-28748

spring-beans/src/test/java/org/springframework/beans/factory/aot/BeanDefinitionMethodGeneratorTests.java

@@ -158,6 +158,45 @@ class BeanDefinitionMethodGeneratorTests {
 		});
 	}
 
+	@Test // gh-28748
+	void generateBeanDefinitionMethodWhenHasInstancePostProcessorAndFactoryMethodGeneratesMethod() {
+		this.beanFactory.registerBeanDefinition("testBeanConfiguration", new RootBeanDefinition(TestBeanConfiguration.class));
+		RootBeanDefinition beanDefinition = new RootBeanDefinition(TestBean.class);
+		beanDefinition.setFactoryBeanName("testBeanConfiguration");
+		beanDefinition.setFactoryMethodName("testBean");
+		RegisteredBean registeredBean = registerBean(beanDefinition);
+		BeanRegistrationAotContribution aotContribution = (generationContext,
+				beanRegistrationCode) -> {
+			GeneratedMethod generatedMethod = beanRegistrationCode.getMethods().add("postProcess", method ->
+					method.addModifiers(Modifier.STATIC)
+							.addParameter(RegisteredBean.class, "registeredBean")
+							.addParameter(TestBean.class, "testBean")
+							.returns(TestBean.class).addCode("return new $T($S);", TestBean.class, "postprocessed"));
+			beanRegistrationCode.addInstancePostProcessor(MethodReference.ofStatic(
+					beanRegistrationCode.getClassName(), generatedMethod.getName()));
+		};
+		List<BeanRegistrationAotContribution> aotContributions = Collections
+				.singletonList(aotContribution);
+		BeanDefinitionMethodGenerator generator = new BeanDefinitionMethodGenerator(
+				this.methodGeneratorFactory, registeredBean, null, aotContributions);
+		MethodReference method = generator.generateBeanDefinitionMethod(
+				this.generationContext, this.beanRegistrationsCode);
+		compile(method, (actual, compiled) -> {
+			assertThat(compiled.getSourceFile(".*BeanDefinitions")).contains("BeanInstanceSupplier");
+			assertThat(actual.getBeanClass()).isEqualTo(TestBean.class);
+			InstanceSupplier<?> supplier = (InstanceSupplier<?>) actual
+					.getInstanceSupplier();
+			try {
+				TestBean instance = (TestBean) supplier.get(registeredBean);
+				assertThat(instance.getName()).isEqualTo("postprocessed");
+			}
+			catch (Exception ex) {
+			}
+			SourceFile sourceFile = compiled.getSourceFile(".*BeanDefinitions");
+			assertThat(sourceFile).contains("instanceSupplier.andThen(");
+		});
+	}
+
 	@Test
 	void generateBeanDefinitionMethodWhenHasCodeFragmentsCustomizerGeneratesMethod() {
 		RegisteredBean registeredBean = registerBean(
@@ -373,7 +412,7 @@ class BeanDefinitionMethodGeneratorTests {
 					.addCode("return $L;", method.toInvokeCodeBlock()).build());
 		});
 		this.generationContext.writeGeneratedContent();
-		TestCompiler.forSystem().withFiles(this.generatedFiles).compile(compiled ->
+		TestCompiler.forSystem().withFiles(this.generatedFiles).printFiles(System.out).compile(compiled ->
 				result.accept((RootBeanDefinition) compiled.getInstance(Supplier.class).get(), compiled));
 	}
 

spring-beans/src/test/java/org/springframework/beans/factory/aot/BeanInstanceSupplierTests.java

@@ -94,7 +94,7 @@ class BeanInstanceSupplierTests {
 
 	@Test
 	void forConstructorWhenNotFoundThrowsException() {
-		BeanInstanceSupplier resolver = BeanInstanceSupplier
+		BeanInstanceSupplier<InputStream> resolver = BeanInstanceSupplier
 				.forConstructor(InputStream.class);
 		Source source = new Source(SingleArgConstructor.class, resolver);
 		RegisteredBean registerBean = source.registerBean(this.beanFactory);
@@ -106,7 +106,7 @@ class BeanInstanceSupplierTests {
 
 	@Test
 	void forConstructorReturnsNullFactoryMethod() {
-		BeanInstanceSupplier resolver = BeanInstanceSupplier.forConstructor(String.class);
+		BeanInstanceSupplier<Object> resolver = BeanInstanceSupplier.forConstructor(String.class);
 		assertThat(resolver.getFactoryMethod()).isNull();
 	}
 
@@ -146,7 +146,7 @@ class BeanInstanceSupplierTests {
 
 	@Test
 	void forFactoryMethodWhenNotFoundThrowsException() {
-		BeanInstanceSupplier resolver = BeanInstanceSupplier
+		BeanInstanceSupplier<InputStream> resolver = BeanInstanceSupplier
 				.forFactoryMethod(SingleArgFactory.class, "single", InputStream.class);
 		Source source = new Source(String.class, resolver);
 		RegisteredBean registerBean = source.registerBean(this.beanFactory);
@@ -158,7 +158,7 @@ class BeanInstanceSupplierTests {
 
 	@Test
 	void forFactoryMethodReturnsFactoryMethod() {
-		BeanInstanceSupplier resolver = BeanInstanceSupplier
+		BeanInstanceSupplier<String> resolver = BeanInstanceSupplier
 				.forFactoryMethod(SingleArgFactory.class, "single", String.class);
 		Method factoryMethod = ReflectionUtils.findMethod(SingleArgFactory.class, "single", String.class);
 		assertThat(factoryMethod).isNotNull();
@@ -167,7 +167,7 @@ class BeanInstanceSupplierTests {
 
 	@Test
 	void withGeneratorWhenBiFunctionIsNullThrowsException() {
-		BeanInstanceSupplier resolver = BeanInstanceSupplier
+		BeanInstanceSupplier<Object> resolver = BeanInstanceSupplier
 				.forConstructor();
 		assertThatIllegalArgumentException()
 				.isThrownBy(() -> resolver.withGenerator(
@@ -177,7 +177,7 @@ class BeanInstanceSupplierTests {
 
 	@Test
 	void withGeneratorWhenFunctionIsNullThrowsException() {
-		BeanInstanceSupplier resolver = BeanInstanceSupplier
+		BeanInstanceSupplier<Object> resolver = BeanInstanceSupplier
 				.forConstructor();
 		assertThatIllegalArgumentException()
 				.isThrownBy(() -> resolver.withGenerator(
@@ -187,7 +187,7 @@ class BeanInstanceSupplierTests {
 
 	@Test
 	void withGeneratorWhenSupplierIsNullThrowsException() {
-		BeanInstanceSupplier resolver = BeanInstanceSupplier
+		BeanInstanceSupplier<Object> resolver = BeanInstanceSupplier
 				.forConstructor();
 		assertThatIllegalArgumentException()
 				.isThrownBy(() -> resolver.withGenerator(
@@ -197,7 +197,7 @@ class BeanInstanceSupplierTests {
 
 	@Test
 	void getWithConstructorDoesNotSetResolvedFactoryMethod() throws Exception {
-		BeanInstanceSupplier resolver = BeanInstanceSupplier
+		BeanInstanceSupplier<SingleArgConstructor> resolver = BeanInstanceSupplier
 				.forConstructor(String.class);
 		this.beanFactory.registerSingleton("one", "1");
 		Source source = new Source(SingleArgConstructor.class, resolver);
@@ -211,7 +211,7 @@ class BeanInstanceSupplierTests {
 	void getWithFactoryMethodSetsResolvedFactoryMethod() {
 		Method factoryMethod = ReflectionUtils.findMethod(SingleArgFactory.class, "single", String.class);
 		assertThat(factoryMethod).isNotNull();
-		BeanInstanceSupplier resolver = BeanInstanceSupplier
+		BeanInstanceSupplier<String> resolver = BeanInstanceSupplier
 				.forFactoryMethod(SingleArgFactory.class, "single", String.class);
 		RootBeanDefinition beanDefinition = new RootBeanDefinition(String.class);
 		assertThat(beanDefinition.getResolvedFactoryMethod()).isNull();
@@ -225,7 +225,7 @@ class BeanInstanceSupplierTests {
 		this.beanFactory.registerSingleton("one", "1");
 		RegisteredBean registerBean = registrar.registerBean(this.beanFactory);
 		List<Object> result = new ArrayList<>();
-		BeanInstanceSupplier resolver = BeanInstanceSupplier
+		BeanInstanceSupplier<Object> resolver = BeanInstanceSupplier
 				.forConstructor(String.class)
 				.withGenerator((registeredBean, args) -> result.add(args));
 		resolver.get(registerBean);
@@ -238,8 +238,8 @@ class BeanInstanceSupplierTests {
 		BeanRegistrar registrar = new BeanRegistrar(SingleArgConstructor.class);
 		this.beanFactory.registerSingleton("one", "1");
 		RegisteredBean registerBean = registrar.registerBean(this.beanFactory);
-		BeanInstanceSupplier resolver = BeanInstanceSupplier
-				.forConstructor(String.class)
+		BeanInstanceSupplier<String> resolver = BeanInstanceSupplier
+				.<String>forConstructor(String.class)
 				.withGenerator(registeredBean -> "1");
 		assertThat(resolver.get(registerBean)).isInstanceOf(String.class).isEqualTo("1");
 	}
@@ -249,15 +249,15 @@ class BeanInstanceSupplierTests {
 		BeanRegistrar registrar = new BeanRegistrar(SingleArgConstructor.class);
 		this.beanFactory.registerSingleton("one", "1");
 		RegisteredBean registerBean = registrar.registerBean(this.beanFactory);
-		BeanInstanceSupplier resolver = BeanInstanceSupplier
-				.forConstructor(String.class)
+		BeanInstanceSupplier<String> resolver = BeanInstanceSupplier
+				.<String>forConstructor(String.class)
 				.withGenerator(() -> "1");
 		assertThat(resolver.get(registerBean)).isInstanceOf(String.class).isEqualTo("1");
 	}
 
 	@Test
 	void getWhenRegisteredBeanIsNullThrowsException() {
-		BeanInstanceSupplier resolver = BeanInstanceSupplier
+		BeanInstanceSupplier<Object> resolver = BeanInstanceSupplier
 				.forConstructor(String.class);
 		assertThatIllegalArgumentException().isThrownBy(() -> resolver.get((RegisteredBean) null))
 				.withMessage("'registeredBean' must not be null");
@@ -548,7 +548,7 @@ class BeanInstanceSupplierTests {
 			}
 
 		};
-		BeanInstanceSupplier resolver = BeanInstanceSupplier
+		BeanInstanceSupplier<Object> resolver = BeanInstanceSupplier
 				.forConstructor(String.class);
 		Source source = new Source(String.class, resolver);
 		beanFactory.registerSingleton("one", "1");
@@ -561,7 +561,7 @@ class BeanInstanceSupplierTests {
 
 	@Test
 	void resolveArgumentsRegistersDependantBeans() {
-		BeanInstanceSupplier resolver = BeanInstanceSupplier
+		BeanInstanceSupplier<Object> resolver = BeanInstanceSupplier
 				.forConstructor(String.class);
 		Source source = new Source(SingleArgConstructor.class, resolver);
 		this.beanFactory.registerSingleton("one", "1");
@@ -724,7 +724,7 @@ class BeanInstanceSupplierTests {
 		protected abstract void setup();
 
 		protected final void add(Class<?> beanClass,
-				BeanInstanceSupplier resolver) {
+				BeanInstanceSupplier<?> resolver) {
 			this.arguments.add(Arguments.of(new Source(beanClass, resolver)));
 		}
 
@@ -762,15 +762,15 @@ class BeanInstanceSupplierTests {
 
 	static class Source extends BeanRegistrar {
 
-		private final BeanInstanceSupplier resolver;
+		private final BeanInstanceSupplier<?> resolver;
 
 		public Source(Class<?> beanClass,
-				BeanInstanceSupplier resolver) {
+				BeanInstanceSupplier<?> resolver) {
 			super(beanClass);
 			this.resolver = resolver;
 		}
 
-		BeanInstanceSupplier getResolver() {
+		BeanInstanceSupplier<?> getResolver() {
 			return this.resolver;
 		}
 

spring-beans/src/test/java/org/springframework/beans/factory/aot/InstanceSupplierCodeGeneratorTests.java

@@ -172,7 +172,7 @@ class InstanceSupplierCodeGeneratorTests {
 					instanceSupplier);
 			assertThat(bean).isInstanceOf(TestBeanWithPrivateConstructor.class);
 			assertThat(compiled.getSourceFile())
-					.contains("return BeanInstanceSupplier.forConstructor();");
+					.contains("return BeanInstanceSupplier.<TestBeanWithPrivateConstructor>forConstructor();");
 		});
 		assertThat(getReflectionHints().getTypeHint(TestBeanWithPrivateConstructor.class))
 				.satisfies(hasConstructorWithMode(ExecutableMode.INVOKE));
@@ -211,7 +211,7 @@ class InstanceSupplierCodeGeneratorTests {
 			assertThat(bean).isInstanceOf(String.class);
 			assertThat(bean).isEqualTo("Hello");
 			assertThat(compiled.getSourceFile())
-					.contains("BeanInstanceSupplier.forFactoryMethod")
+					.contains("forFactoryMethod")
 					.doesNotContain("withGenerator");
 		});
 		assertThat(getReflectionHints().getTypeHint(SimpleConfiguration.class))
@@ -325,7 +325,7 @@ class InstanceSupplierCodeGeneratorTests {
 					.addStatement("return $L", generatedCode).build());
 		});
 		this.generationContext.writeGeneratedContent();
-		TestCompiler.forSystem().withFiles(this.generatedFiles).compile(compiled ->
+		TestCompiler.forSystem().withFiles(this.generatedFiles).printFiles(System.out).compile(compiled ->
 			result.accept((InstanceSupplier<?>) compiled.getInstance(Supplier.class).get(), compiled));
 	}
 

spring-beans/src/test/java/org/springframework/beans/factory/aot/TestBeanConfiguration.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2002-2022 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.beans.factory.aot;
+
+import org.springframework.beans.testfixture.beans.TestBean;
+
+/**
+ * Test {@code @Configuration} style class to create {@link TestBean}.
+ *
+ * @author Phillip Webb
+ */
+public class TestBeanConfiguration {
+
+	public TestBean testBean() {
+		return new TestBean();
+	}
+
+}