core/src/test/java/org/jclouds/util/Suppliers2Test.java

/**
 * Licensed to jclouds, Inc. (jclouds) under one or more
 * contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  jclouds licenses this file
 * to you 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 org.jclouds.util;

import static org.testng.Assert.assertEquals;

import java.util.Map;
import java.util.NoSuchElementException;

import org.testng.annotations.Test;

import com.google.common.base.Supplier;
import com.google.common.base.Suppliers;
import com.google.common.collect.ImmutableMap;

public class Suppliers2Test {

   @Test
   public void testGetLastValueInMap() {
      assertEquals(
               Suppliers2.<String, String> getLastValueInMap(
                        Suppliers.<Map<String, Supplier<String>>> ofInstance(ImmutableMap.of("foo",
                                 Suppliers.ofInstance("bar")))).get(), "bar");
   }

   @Test
   public void testOfInstanceFunction() {
      assertEquals(Suppliers2.ofInstanceFunction().apply("foo").get(), "foo");
   }

   @Test
   public void testOrWhenFirstNull() {
      assertEquals(Suppliers2.or(Suppliers.<String> ofInstance(null), Suppliers.ofInstance("foo")).get(), "foo");
   }

   @Test
   public void testOrWhenFirstNotNull() {
      assertEquals(Suppliers2.or(Suppliers.<String> ofInstance("foo"), Suppliers.ofInstance("bar")).get(), "foo");
   }

   @Test
   public void testOnThrowableWhenFirstThrowsMatchingException() {
      assertEquals(Suppliers2.onThrowable(new Supplier<String>() {

         @Override
         public String get() {
            throw new NoSuchElementException();
         }

      }, NoSuchElementException.class, Suppliers.ofInstance("foo")).get(), "foo");
   }

   @Test(expectedExceptions = RuntimeException.class)
   public void testOnThrowableWhenFirstThrowsUnmatchingException() {
      Suppliers2.onThrowable(new Supplier<String>() {

         @Override
         public String get() {
            throw new RuntimeException();
         }

      }, NoSuchElementException.class, Suppliers.ofInstance("foo")).get();
   }

   @Test
   public void testOnThrowableWhenFirstIsFine() {
      assertEquals(
               Suppliers2.onThrowable(Suppliers.<String> ofInstance("foo"), NoSuchElementException.class,
                        Suppliers.ofInstance("bar")).get(), "foo");
   }

   
   @Test
   public void testCombination() {
      Supplier<String> alternate = Suppliers.ofInstance("bar");
      Supplier<String> or = Suppliers2.or(Suppliers.<String> ofInstance("foo"), alternate);
      Supplier<String> combined = Suppliers2.onThrowable(or, NoSuchElementException.class, alternate);    
      
      assertEquals(combined.get(), "foo");
   }

}