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      1 /**
      2  * Copyright (C) 2008 Google Inc.
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  * http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.google.inject.spi;
     18 
     19 import com.google.common.collect.Lists;
     20 import com.google.inject.AbstractModule;
     21 import com.google.inject.Binding;
     22 import com.google.inject.ConfigurationException;
     23 import com.google.inject.Guice;
     24 import com.google.inject.Inject;
     25 import com.google.inject.Injector;
     26 import com.google.inject.Key;
     27 import com.google.inject.Module;
     28 import com.google.inject.Provider;
     29 import com.google.inject.name.Names;
     30 
     31 import junit.framework.TestCase;
     32 
     33 import java.util.List;
     34 
     35 /**
     36  * @author jessewilson (at) google.com (Jesse Wilson)
     37  */
     38 public class ModuleRewriterTest extends TestCase {
     39 
     40   public void testRewriteBindings() {
     41     // create a module the binds String.class and CharSequence.class
     42     Module module = new AbstractModule() {
     43       protected void configure() {
     44         bind(String.class).toInstance("Pizza");
     45         bind(CharSequence.class).toInstance("Wine");
     46       }
     47     };
     48 
     49     // record the elements from that module
     50     List<Element> elements = Elements.getElements(module);
     51 
     52     // create a rewriter that rewrites the binding to 'Wine' with a binding to 'Beer'
     53     List<Element> rewritten = Lists.newArrayList();
     54     for (Element element : elements) {
     55       element = element.acceptVisitor(new DefaultElementVisitor<Element>() {
     56         @Override public <T> Element visit(Binding<T> binding) {
     57           T target = binding.acceptTargetVisitor(Elements.<T>getInstanceVisitor());
     58           if ("Wine".equals(target)) {
     59             return null;
     60           }
     61           else {
     62             return binding;
     63           }
     64         }
     65       });
     66       if (element != null) {
     67         rewritten.add(element);
     68       }
     69     }
     70 
     71     // create a module from the original list of elements and the rewriter
     72     Module rewrittenModule = Elements.getModule(rewritten);
     73 
     74     // the wine binding is dropped
     75     Injector injector = Guice.createInjector(rewrittenModule);
     76     try {
     77       injector.getInstance(CharSequence.class);
     78       fail();
     79     } catch (ConfigurationException expected) {
     80     }
     81   }
     82 
     83   public void testGetProviderAvailableAtInjectMembersTime() {
     84     Module module = new AbstractModule() {
     85       public void configure() {
     86         final Provider<String> stringProvider = getProvider(String.class);
     87 
     88         bind(String.class).annotatedWith(Names.named("2")).toProvider(new Provider<String>() {
     89           private String value;
     90 
     91           @Inject void initialize() {
     92             value = stringProvider.get();
     93           }
     94 
     95           public String get() {
     96             return value;
     97           }
     98         });
     99 
    100         bind(String.class).toInstance("A");
    101       }
    102     };
    103 
    104     // the module works fine normally
    105     Injector injector = Guice.createInjector(module);
    106     assertEquals("A", injector.getInstance(Key.get(String.class, Names.named("2"))));
    107 
    108     // and it should also work fine if we rewrite it
    109     List<Element> elements = Elements.getElements(module);
    110     Module replayed = Elements.getModule(elements);
    111     Injector replayedInjector = Guice.createInjector(replayed);
    112     assertEquals("A", replayedInjector.getInstance(Key.get(String.class, Names.named("2"))));
    113   }
    114 }
    115