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/*
* Copyright (C) 2011 The Guava Authors
*
* 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.common.collect;
import static com.google.common.truth.Truth.assertThat;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.base.Function;
import com.google.common.testing.NullPointerTester;
import java.util.Arrays;
import java.util.List;
import junit.framework.TestCase;
/**
* Tests for {@code TreeTraverser}.
*
* @author Louis Wasserman
*/
@GwtCompatible(emulated = true)
public class TreeTraverserTest extends TestCase {
private static class Node {
final char value;
Node(char value) {
this.value = value;
}
}
private static final class Tree extends Node {
final List<Tree> children;
public Tree(char value, Tree... children) {
super(value);
this.children = Arrays.asList(children);
}
}
private static final TreeTraverser<Tree> ADAPTER =
new TreeTraverser<Tree>() {
@Override
public Iterable<Tree> children(Tree node) {
return node.children;
}
};
private static final TreeTraverser<Tree> ADAPTER_USING_USING =
TreeTraverser.using(
new Function<Tree, Iterable<Tree>>() {
@Override
public Iterable<Tree> apply(Tree node) {
return node.children;
}
});
// h
// / | \
// / e \
// d g
// /|\ |
// / | \ f
// a b c
static final Tree a = new Tree('a');
static final Tree b = new Tree('b');
static final Tree c = new Tree('c');
static final Tree d = new Tree('d', a, b, c);
static final Tree e = new Tree('e');
static final Tree f = new Tree('f');
static final Tree g = new Tree('g', f);
static final Tree h = new Tree('h', d, e, g);
static String iterationOrder(Iterable<? extends Node> iterable) {
StringBuilder builder = new StringBuilder();
for (Node t : iterable) {
builder.append(t.value);
}
return builder.toString();
}
public void testPreOrder() {
assertThat(iterationOrder(ADAPTER.preOrderTraversal(h))).isEqualTo("hdabcegf");
}
public void testPostOrder() {
assertThat(iterationOrder(ADAPTER.postOrderTraversal(h))).isEqualTo("abcdefgh");
}
public void testBreadthOrder() {
assertThat(iterationOrder(ADAPTER.breadthFirstTraversal(h))).isEqualTo("hdegabcf");
}
public void testUsing() {
assertThat(iterationOrder(ADAPTER_USING_USING.preOrderTraversal(h))).isEqualTo("hdabcegf");
}
@GwtIncompatible // NullPointerTester
public void testNulls() {
NullPointerTester tester = new NullPointerTester();
tester.testAllPublicInstanceMethods(ADAPTER);
}
}
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