core/test/com/google/inject/name/NamedEquivalanceTest.java

/**
 * Copyright (C) 2010 Google Inc.
 *
 * 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
 *
 * http://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 com.google.inject.name;

import static com.google.inject.Asserts.assertContains;

import com.google.inject.AbstractModule;
import com.google.inject.ConfigurationException;
import com.google.inject.CreationException;
import com.google.inject.Guice;
import com.google.inject.Inject;
import com.google.inject.Injector;
import com.google.inject.Key;
import com.google.inject.Module;
import com.google.inject.Provides;

import junit.framework.TestCase;

import java.io.Serializable;
import java.lang.annotation.Annotation;
import java.util.Properties;

/**
 * Tests that {@code javax.inject.Named} and {@code com.google.inject.name.Named} are completely
 * interchangeable: bindings for one can be used to inject the other.
 * 
 * @author cgdecker@gmail.com (Colin Decker)
 */
public class NamedEquivalanceTest extends TestCase {

  private static final Module GUICE_BINDING_MODULE = moduleWithAnnotation(Names.named("foo"));
  private static final Module JSR330_BINDING_MODULE = moduleWithAnnotation(new JsrNamed("foo"));
  private static final Module GUICE_PROVIDER_METHOD_MODULE = getGuiceBindingProviderMethodModule();
  private static final Module JSR330_PROVIDER_METHOD_MODULE = getJsr330BindingProviderMethodModule();

  public void testKeysCreatedWithDifferentTypesAreEqual() {
    assertEquals(keyForAnnotation(new GuiceNamed("foo")), keyForAnnotation(new JsrNamed("foo")));
    assertEquals(keyForAnnotation(Names.named("foo")), keyForAnnotation(new GuiceNamed("foo")));
    assertEquals(keyForAnnotation(Names.named("foo")), keyForAnnotation(new JsrNamed("foo")));

    assertEquals(keyForAnnotationType(com.google.inject.name.Named.class),
        keyForAnnotationType(javax.inject.Named.class));
  }

  private static Key<String> keyForAnnotation(Annotation annotation) {
    return Key.get(String.class, annotation);
  }
  
  private static Key<String> keyForAnnotationType(Class<? extends Annotation> annotationType) {
    return Key.get(String.class, annotationType);
  }

  public void testBindingWithNamesCanInjectBothTypes() {
    assertInjectionsSucceed(GUICE_BINDING_MODULE);
  }

  public void testBindingWithJsr330AnnotationCanInjectBothTypes() {
    assertInjectionsSucceed(JSR330_BINDING_MODULE);
  }

  public void testBindingWithGuiceNamedAnnotatedProviderMethodCanInjectBothTypes() {
    assertInjectionsSucceed(GUICE_PROVIDER_METHOD_MODULE);
  }

  public void testBindingWithJsr330NamedAnnotatedProviderMethodCanInjectBothTypes() {
    assertInjectionsSucceed(JSR330_PROVIDER_METHOD_MODULE);
  }

  public void testBindingDifferentTypesWithSameValueIsIgnored() {
    assertDuplicateBinding(GUICE_BINDING_MODULE, JSR330_BINDING_MODULE, false);
    assertDuplicateBinding(JSR330_BINDING_MODULE, GUICE_BINDING_MODULE, false);
  }

  public void testBindingDifferentTypesWithSameValueIsAnErrorWithProviderMethods() {
    assertDuplicateBinding(GUICE_PROVIDER_METHOD_MODULE, JSR330_PROVIDER_METHOD_MODULE, true);
    assertDuplicateBinding(JSR330_PROVIDER_METHOD_MODULE, GUICE_PROVIDER_METHOD_MODULE, true);
  }

  public void testBindingDifferentTypesWithSameValueIsAnErrorMixed() {
    assertDuplicateBinding(GUICE_BINDING_MODULE, JSR330_PROVIDER_METHOD_MODULE, true);
    assertDuplicateBinding(JSR330_BINDING_MODULE, GUICE_PROVIDER_METHOD_MODULE, true);
  }

  public void testMissingBindingForGuiceNamedUsesSameTypeInErrorMessage() {
    assertMissingBindingErrorMessageUsesType(GuiceNamedClient.class);
  }

  public void testMissingBindingForJsr330NamedUsesSameTypeInErrorMessage() {
    assertMissingBindingErrorMessageUsesType(Jsr330NamedClient.class);
  }

  public void testBindPropertiesWorksWithJsr330() {
    assertInjectionsSucceed(new AbstractModule() {
      @Override protected void configure() {
        Properties properties = new Properties();
        properties.put("foo", "bar");
        Names.bindProperties(binder(), properties);
      }
    });
  }

  private static void assertMissingBindingErrorMessageUsesType(Class<?> clientType) {
    try {
      Guice.createInjector().getInstance(clientType);
      fail("should have thrown ConfigurationException");
    } catch (ConfigurationException e) {
      assertContains(e.getMessage(),
          "No implementation for java.lang.String annotated with @com.google.inject.name.Named(value=foo) was bound.");
    }
  }

  private static void assertDuplicateBinding(Module a, Module b, boolean fails) {
    try {
      Guice.createInjector(a, b);
      if(fails) {
        fail("should have thrown CreationException");
      }
    } catch (CreationException e) {
      if(fails) {
        assertContains(e.getMessage(),
            "A binding to java.lang.String annotated with @com.google.inject.name.Named(value=foo) was already configured");
      } else {
        throw e;
      }
    }
  }

  private static Module moduleWithAnnotation(final Annotation annotation) {
    return new AbstractModule() {
      @Override protected void configure() {
        bindConstant().annotatedWith(annotation).to("bar");
      }
    };
  }

  private static void assertInjectionsSucceed(Module module) {
    Injector injector = Guice.createInjector(module);
    assertInjected(injector.getInstance(GuiceNamedClient.class), injector
        .getInstance(Jsr330NamedClient.class));
  }

  private static void assertInjected(GuiceNamedClient guiceClient, Jsr330NamedClient jsr330Client) {
    assertEquals("bar", guiceClient.foo);
    assertEquals("bar", jsr330Client.foo);
  }

  private static Module getJsr330BindingProviderMethodModule() {
    return new AbstractModule() {
      @Override protected void configure() {}
      @SuppressWarnings("unused") @Provides @javax.inject.Named("foo") String provideFoo() {
        return "bar";
      }
    };
  }

  private static Module getGuiceBindingProviderMethodModule() {
    return new AbstractModule() {
      @Override protected void configure() {}
      @SuppressWarnings("unused") @Provides @Named("foo") String provideFoo() {
        return "bar";
      }
    };
  }

  private static class GuiceNamedClient {
    @Inject @Named("foo") String foo;
  }

  private static class Jsr330NamedClient {
    @Inject @javax.inject.Named("foo") String foo;
  }

  private static class JsrNamed implements javax.inject.Named, Serializable {
    private final String value;

    public JsrNamed(String value) {
      this.value = value;
    }

    public String value() {
      return this.value;
    }

    public int hashCode() {
      // This is specified in java.lang.Annotation.
      return (127 * "value".hashCode()) ^ value.hashCode();
    }

    public boolean equals(Object o) {
      if (!(o instanceof javax.inject.Named)) {
        return false;
      }

      javax.inject.Named other = (javax.inject.Named) o;
      return value.equals(other.value());
    }

    public String toString() {
      return "@" + javax.inject.Named.class.getName() + "(value=" + value + ")";
    }

    public Class<? extends Annotation> annotationType() {
      return javax.inject.Named.class;
    }

    private static final long serialVersionUID = 0;
  }

  private static class GuiceNamed implements com.google.inject.name.Named, Serializable {
    private final String value;
    
    public GuiceNamed(String value) {
      this.value = value;
    }
    
    public String value() {
      return this.value;
    }
    
    public int hashCode() {
      // This is specified in java.lang.Annotation.
      return (127 * "value".hashCode()) ^ value.hashCode();
    }

    public boolean equals(Object o) {
      if (!(o instanceof com.google.inject.name.Named)) {
        return false;
      }

      com.google.inject.name.Named other = (com.google.inject.name.Named) o;
      return value.equals(other.value());
    }

    public String toString() {
      return "@" + com.google.inject.name.Named.class.getName() + "(value=" + value + ")";
    }

    public Class<? extends Annotation> annotationType() {
      return com.google.inject.name.Named.class;
    }

    private static final long serialVersionUID = 0;
  }
}