Restore support for Guice PrivateModule's

See #32

src/main/java/org/springframework/guice/annotation/ModuleRegistryConfiguration.java

@@ -29,6 +29,7 @@ import com.google.inject.name.Named;
 import com.google.inject.spi.Element;
 import com.google.inject.spi.ElementSource;
 import com.google.inject.spi.Elements;
+import com.google.inject.spi.PrivateElements;
 
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.NoSuchBeanDefinitionException;
@@ -87,7 +88,7 @@ class ModuleRegistryConfiguration implements BeanDefinitionRegistryPostProcessor
 		if (injector == null) {
 			injector = Guice.createInjector(modules);
 		}
-		beanFactory.registerResolvableDependency(Injector.class, injector);
+		beanFactory.registerSingleton("injector", injector);
 	}
 
 	private void mapBindings(Map<Key<?>, Binding<?>> bindings,
@@ -138,6 +139,8 @@ class ModuleRegistryConfiguration implements BeanDefinitionRegistryPostProcessor
 			if (e instanceof Binding) {
 				Binding<?> binding = (Binding<?>) e;
 				bindings.put(binding.getKey(), binding);
+			} else if (e instanceof PrivateElements) {
+				extractPrivateElements(bindings, (PrivateElements) e);
 			}
 		}
 		mapBindings(bindings, registry);
@@ -148,6 +151,18 @@ class ModuleRegistryConfiguration implements BeanDefinitionRegistryPostProcessor
 		applicationContext.publishEvent(new CreateInjectorSignalEvent());
 	}
 
+	private void extractPrivateElements(Map<Key<?>, Binding<?>> bindings, PrivateElements privateElements) {
+		List<Element> elements = privateElements.getElements();
+		for (Element e : elements) {
+			if (e instanceof Binding && privateElements.getExposedKeys().contains(((Binding<?>) e).getKey())) {
+				Binding<?> binding = (Binding<?>) e;
+				bindings.put(binding.getKey(), binding);
+			} else if (e instanceof PrivateElements) {
+				extractPrivateElements(bindings, (PrivateElements) e);
+			}
+		}
+	}
+
 	@Override
 	public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory)
 			throws BeansException {

src/test/java/org/springframework/guice/PrivateModuleTests.java

@@ -0,0 +1,99 @@
+package org.springframework.guice;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.springframework.beans.factory.NoSuchBeanDefinitionException;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.guice.PrivateModuleTests.SomeInterface;
+import org.springframework.guice.PrivateModuleTests.SomePrivateModule;
+import org.springframework.guice.annotation.EnableGuiceModules;
+
+import com.google.inject.AbstractModule;
+import com.google.inject.ConfigurationException;
+import com.google.inject.Injector;
+import com.google.inject.Key;
+import com.google.inject.Module;
+import com.google.inject.PrivateModule;
+import com.google.inject.name.Names;
+
+public class PrivateModuleTests {
+
+	private static AnnotationConfigApplicationContext context;
+	
+	@BeforeClass
+	public static void init() {
+		context = new AnnotationConfigApplicationContext(PrivateModuleTestConfig.class);
+	}
+	
+	@AfterClass
+	public static void cleanup() {
+		if(context != null) {
+			context.close();
+		}
+	}
+
+	@Test
+	public void verifyPrivateModulesCanExposeBindings() {	
+		Injector injector = context.getBean(Injector.class);
+		SomeInterface injectorProvidedPrivateBinding = injector.getInstance(Key.get(SomeInterface.class, Names.named("exposed")));
+		assertNotNull(injectorProvidedPrivateBinding);
+		SomeInterface springProvidedPrivateBinding = context.getBean(SomeInterface.class);
+		assertNotNull(springProvidedPrivateBinding);
+		SomeInterface namedPrivateBinding = context.getBean("exposed",SomeInterface.class);
+		assertNotNull(namedPrivateBinding);
+		assertEquals(injectorProvidedPrivateBinding, springProvidedPrivateBinding);
+		assertEquals(injectorProvidedPrivateBinding, namedPrivateBinding);
+		String beanDependingOnPrivateBinding = context.getBean("somethingThatWantsAPrivateBinding", String.class);
+		assertNotNull(beanDependingOnPrivateBinding);
+		assertEquals("foo", beanDependingOnPrivateBinding);
+	}
+	
+	@Test(expected=ConfigurationException.class)
+	public void verifyPrivateModulesPrivateBindingsAreNotExposedViaInjector() {
+		Injector injector = context.getBean(Injector.class);
+		injector.getInstance(Key.get(SomeInterface.class, Names.named("notexposed")));
+	}
+	
+	@Test(expected=NoSuchBeanDefinitionException.class)
+	public void verifyPrivateModulesPrivateBindingsAreNotExposedViaSpring() {
+		context.getBean("notexposed",SomeInterface.class);
+	}
+
+	public static interface SomeInterface {}
+	public static class SomePrivateBinding implements SomeInterface {}
+	
+	public static class SomePrivateModule extends PrivateModule {
+		@Override
+		protected void configure() {
+			bind(SomeInterface.class).annotatedWith(Names.named("exposed")).to(SomePrivateBinding.class).asEagerSingleton();
+			bind(SomeInterface.class).annotatedWith(Names.named("notexposed")).to(SomePrivateBinding.class).asEagerSingleton();
+			expose(SomeInterface.class).annotatedWith(Names.named("exposed"));	
+		}
+	}
+}
+
+@EnableGuiceModules
+@Configuration
+class PrivateModuleTestConfig {
+	
+	@Bean
+	public String somethingThatWantsAPrivateBinding(SomeInterface privateBinding) {
+		return "foo";
+	}
+	
+	@Bean
+	public Module module() {
+		return new AbstractModule() {
+			@Override
+			protected void configure() {
+				install(new SomePrivateModule());
+			}
+		};
+	}
+}