| 1 | /******************************************************************************* |
| 2 | * Copyright (c) 2015 EfficiOS Inc., Alexandre Montplaisir |
| 3 | * |
| 4 | * All rights reserved. This program and the accompanying materials |
| 5 | * are made available under the terms of the Eclipse Public License v1.0 |
| 6 | * which accompanies this distribution, and is available at |
| 7 | * http://www.eclipse.org/legal/epl-v10.html |
| 8 | *******************************************************************************/ |
| 9 | |
| 10 | package org.eclipse.tracecompass.common.core.tests.collect; |
| 11 | |
| 12 | import static org.junit.Assert.assertEquals; |
| 13 | |
| 14 | import java.util.Arrays; |
| 15 | import java.util.List; |
| 16 | import java.util.stream.Collectors; |
| 17 | |
| 18 | import org.eclipse.tracecompass.common.core.collect.StreamFlattener; |
| 19 | import org.junit.Test; |
| 20 | |
| 21 | /** |
| 22 | * Test for {@link StreamFlattener}. |
| 23 | * |
| 24 | * @author Alexandre Montplaisir |
| 25 | */ |
| 26 | public class StreamFlattenerTest { |
| 27 | |
| 28 | /** |
| 29 | * Test flattening a tree. |
| 30 | * |
| 31 | * Each node has a String value, and they will be organized as: |
| 32 | * |
| 33 | * <pre> |
| 34 | * A |
| 35 | * / \ |
| 36 | * B C |
| 37 | * /| |\ |
| 38 | * D E F G |
| 39 | * </pre> |
| 40 | * |
| 41 | * In-order, depth-first visiting should give the following sequence:<br> |
| 42 | * A -> B -> D -> E -> C -> F -> G |
| 43 | */ |
| 44 | @Test |
| 45 | public void testFlattenTree() { |
| 46 | /* Prepare the tree */ |
| 47 | TreeNode nodeD = new TreeNode(new TreeNode[0], "D"); |
| 48 | TreeNode nodeE = new TreeNode(new TreeNode[0], "E"); |
| 49 | TreeNode nodeF = new TreeNode(new TreeNode[0], "F"); |
| 50 | TreeNode nodeG = new TreeNode(new TreeNode[0], "G"); |
| 51 | TreeNode nodeB = new TreeNode(new TreeNode[] {nodeD, nodeE}, "B"); |
| 52 | TreeNode nodeC = new TreeNode(new TreeNode[] {nodeF, nodeG}, "C"); |
| 53 | TreeNode nodeA = new TreeNode(new TreeNode[] {nodeB, nodeC}, "A"); |
| 54 | |
| 55 | /* Run the test */ |
| 56 | StreamFlattener<TreeNode> sf = new StreamFlattener<>(node -> Arrays.stream(node.getChildren())); |
| 57 | |
| 58 | List<String> expected = Arrays.asList("A", "B", "D", "E", "C", "F", "G"); |
| 59 | List<String> results = sf.flatten(nodeA).map(TreeNode::getValue).collect(Collectors.toList()); |
| 60 | |
| 61 | assertEquals(expected, results); |
| 62 | } |
| 63 | |
| 64 | private static class TreeNode { |
| 65 | |
| 66 | private final TreeNode[] children; |
| 67 | private final String value; |
| 68 | |
| 69 | public TreeNode(TreeNode[] children, String value) { |
| 70 | this.children = children; |
| 71 | this.value = value; |
| 72 | } |
| 73 | |
| 74 | public TreeNode[] getChildren() { |
| 75 | return children; |
| 76 | } |
| 77 | |
| 78 | public String getValue() { |
| 79 | return value; |
| 80 | } |
| 81 | } |
| 82 | } |