@ImportTestcontainers doesn't work with AOT

[nosan]

#42875

Since Bean's InstanceSupplier cannot be used during the AOT process, I added BeanRegistrationAotProcessor to replace it.

If a container's field is inaccessible, the generated code will be:

@Generated
public class GraalmavenApplicationTests__TestContext001_BeanDefinitions {

	/**
	 * Get the bean instance for 'importTestContainer.task.graalmaven.GraalmavenApplicationTests.mongoDbContainer'.
	 */
	private static MongoDBContainer getMongoDbContainerInstance() {
		try {
			Class<?> clazz = ClassUtils.forName("task.graalmaven.GraalmavenApplicationTests",
					GraalmavenApplicationTests__TestContext001_BeanDefinitions.class.getClassLoader());
			Field field = ReflectionUtils.findField(clazz, "mongoDbContainer");
			Assert.notNull(field, "Field 'mongoDbContainer' is not found");
			ReflectionUtils.makeAccessible(field);
			Object container = ReflectionUtils.getField(field, null);
			Assert.notNull(container, "Container field 'mongoDbContainer' must not have a null value");
			return (MongoDBContainer) container;
		} catch (ClassNotFoundException ex) {
			throw new RuntimeException(ex);
		}
	}

	/**
	 * Get the bean definition for 'mongoDbContainer'.
	 */
	public static BeanDefinition getMongoDbContainerBeanDefinition() {
		RootBeanDefinition beanDefinition = new RootBeanDefinition(MongoDBContainer.class);
		beanDefinition.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
		beanDefinition.setInstanceSupplier(
				GraalmavenApplicationTests__TestContext001_BeanDefinitions::getMongoDbContainerInstance);
		return beanDefinition;
	}

}

If a container's field is accessible, the generated code will be:

@Generated
public class GraalmavenApplicationTests__TestContext001_BeanDefinitions {
  /**
   * Get the bean definition for 'mongoDbContainer'.
   */
  public static BeanDefinition getMongoDbContainerBeanDefinition() {
    RootBeanDefinition beanDefinition = new RootBeanDefinition(MyContainer.class);
    beanDefinition.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
    beanDefinition.setInstanceSupplier(() -> GraalmavenApplicationTests.mongoDbContainer);
    return beanDefinition;
  }
}

An alternative way is FactoryBean instead of InstanceSupplier.

The target branch is 3.2.x

[nosan]

Another idea that came to my mind is to replace ImportTestcontainersRegistrar with ContextCustomizerFactory.
In that case only BeanRegistrationExcludeFilter is needed to exclude TestcontainerFieldBeanDefinition.

Similar to ServiceConnectionContextCustomizerFactory

[nosan]

Unfortunately, handling the bean instance supplier for container fields only addresses
half of the issue. The more problematic part involves handling @DynamicPropertySource
methods. These @DynamicPropertySource methods need to be generated and invoked within
the AOT environment. To achieve this, I introduced
DynamicPropertySourceBeanFactoryInitializationAotProcessor

[nosan]

Initially, my idea was to generate code similar to ImportTestcontainersRegistrar. However,
I realized that instead of generating all bean definitions and @DynamicPropertySource methods, I could create a class delegate that delegates bean definition registration to the existing ImportTestcontainersRegistrar.

public class TestA__TestContext001_ApplicationContextInitializer implements ApplicationContextInitializer<GenericApplicationContext> {
  @Override
  public void initialize(GenericApplicationContext applicationContext) {
    DefaultListableBeanFactory beanFactory = applicationContext.getDefaultListableBeanFactory();
    beanFactory.setAutowireCandidateResolver(new ContextAnnotationAutowireCandidateResolver());
    beanFactory.setDependencyComparator(AnnotationAwareOrderComparator.INSTANCE);
    new TestA__TestContext001_BeanFactoryRegistrations().registerBeanDefinitions(beanFactory);
    new TestA__TestContext001_BeanFactoryRegistrations().registerAliases(beanFactory);
    ImportTestcontainersRegistrar__TestContext001_ImportTestcontainers.registerBeanDefinitions(applicationContext.getEnvironment(), beanFactory);
  }
}

@Generated
public class ImportTestcontainersRegistrar__TestContext001_ImportTestcontainers {
  /**
   * Register bean definitions for 'ImportTestcontainers'
   */
  public static void registerBeanDefinitions(ConfigurableEnvironment environment,
      DefaultListableBeanFactory beanFactory) {
    Set<Class<?>> definitionClasses = new LinkedHashSet<>();
    definitionClasses.add(ClassUtils.resolveClassName("task.graalmaven.TestcontainersConfiguration", beanFactory.getBeanClassLoader()));
    definitionClasses.add(ClassUtils.resolveClassName("task.graalmaven.GraalmavenApplicationTests", beanFactory.getBeanClassLoader()));
    new ImportTestcontainersRegistrar(environment).registerBeanDefinitions(beanFactory, definitionClasses.toArray(new Class<?>[0]));
  }
}

If it is wrong, the previous af6ce70 commit generates bean definitions and @DynamicPropertySource methods

@Generated
public class TestA__TestContext001_ApplicationContextInitializer implements ApplicationContextInitializer<GenericApplicationContext> {
  @Override
  public void initialize(GenericApplicationContext applicationContext) {
    DefaultListableBeanFactory beanFactory = applicationContext.getDefaultListableBeanFactory();
    beanFactory.setAutowireCandidateResolver(new ContextAnnotationAutowireCandidateResolver());
    beanFactory.setDependencyComparator(AnnotationAwareOrderComparator.INSTANCE);
    new TestA__TestContext001_BeanFactoryRegistrations().registerBeanDefinitions(beanFactory);
    new TestA__TestContext001_BeanFactoryRegistrations().registerAliases(beanFactory);
    registerDynamicPropertySources(applicationContext.getEnvironment(), beanFactory);
  }

  /**
   * Registers {@code @DynamicPropertySource} properties
   */
  private static void registerDynamicPropertySources(ConfigurableEnvironment environment,
      DefaultListableBeanFactory beanFactory) {
    DynamicPropertyRegistry dynamicPropertyRegistry = TestcontainersPropertySource.attach(environment, beanFactory);
    GraalmavenApplicationTests__TestContext001_DynamicPropertySource.registerDynamicPropertySource(dynamicPropertyRegistry);
  }
}

@Generated
public class GraalmavenApplicationTests__TestContext001_DynamicPropertySource {
  /**
   * Register {@code @DynamicPropertySource} for method 'GraalmavenApplicationTests.mongoProperties'
   */
  private static void mongoProperties(DynamicPropertyRegistry dynamicPropertyRegistry) {
    Class<?> clazz = ClassUtils.resolveClassName("task.graalmaven.GraalmavenApplicationTests", GraalmavenApplicationTests__TestContext001_DynamicPropertySource.class.getClassLoader());
    ReflectionTestUtils.invokeMethod(clazz, "mongoProperties", dynamicPropertyRegistry);
  }

  /**
   * Registers {@code @DynamicPropertySource} properties for class 'GraalmavenApplicationTests'
   */
  public static void registerDynamicPropertySource(
      DynamicPropertyRegistry dynamicPropertyRegistry) {
    GraalmavenApplicationTests__TestContext001_DynamicPropertySource.mongoProperties(dynamicPropertyRegistry);
  }
}

@Generated
public class GraalmavenApplicationTests__TestContext001_BeanDefinitions {

	/**
	 * Get the bean instance for 'importTestContainer.task.graalmaven.GraalmavenApplicationTests.mongoDbContainer'.
	 */
	private static MongoDBContainer getMongoDbContainerInstance() {
		Class<?> clazz = ClassUtils.resolveClassName("task.graalmaven.GraalmavenApplicationTests",
				GraalmavenApplicationTests__TestContext001_BeanDefinitions.class.getClassLoader());
		Field field = ReflectionUtils.findField(clazz, "mongoDbContainer");
		Assert.notNull(field, "Field 'mongoDbContainer' is not found");
		ReflectionUtils.makeAccessible(field);
		Object container = ReflectionUtils.getField(field, null);
		Assert.notNull(container, "Container field 'mongoDbContainer' must not have a null value");
		return (MongoDBContainer) container;
	}

	/**
	 * Get the bean definition for 'mongoDbContainer'.
	 */
	public static BeanDefinition getMongoDbContainerBeanDefinition() {
		RootBeanDefinition beanDefinition = new RootBeanDefinition(MongoDBContainer.class);
		beanDefinition.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
		beanDefinition.setInstanceSupplier(
				GraalmavenApplicationTests__TestContext001_BeanDefinitions::getMongoDbContainerInstance);
		return beanDefinition;
	}

}

[nosan]

@philwebb
Could I kindly ask you to do a quick review of this PR, and let me know if I'm in the right direction?