utils/misc/src/test/java/org/onlab/graph/BreadthFirstSearchTest.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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.onlab.graph;

import org.junit.Test;

import java.util.Set;

import static org.junit.Assert.assertEquals;

/**
 * Test of the BFS and similar path search algorithms.
 */
public class BreadthFirstSearchTest extends AbstractGraphPathSearchTest {

    @Override
    protected AbstractGraphPathSearch<TestVertex, TestEdge> graphSearch() {
        return new BreadthFirstSearch<>();
    }

    @Test
    public void defaultGraphTest() {
        executeDefaultTest(7, 3, 8.0);
    }

    @Test
    public void defaultHopCountWeight() {
        weight = null;
        executeDefaultTest(7, 3, 3.0);
    }

    // Executes the default test
    protected void executeDefaultTest(int pathCount, int pathLength, double pathCost) {
        graph = new AdjacencyListsGraph<>(vertexes(), edges());

        GraphPathSearch<TestVertex, TestEdge> search = graphSearch();
        Set<Path<TestVertex, TestEdge>> paths = search.search(graph, A, H, weight).paths();
        assertEquals("incorrect paths count", 1, paths.size());

        Path p = paths.iterator().next();
        assertEquals("incorrect src", A, p.src());
        assertEquals("incorrect dst", H, p.dst());
        assertEquals("incorrect path length", pathLength, p.edges().size());
        assertEquals("incorrect path cost", pathCost, p.cost(), 0.1);

        paths = search.search(graph, A, null, weight).paths();
        printPaths(paths);
        assertEquals("incorrect paths count", pathCount, paths.size());
    }

    // Executes the search and validates its results.
    protected void executeSearch(GraphPathSearch<TestVertex, TestEdge> search,
                                 Graph<TestVertex, TestEdge> graph,
                                 TestVertex src, TestVertex dst,
                                 EdgeWeight<TestVertex, TestEdge> weight,
                                 int pathCount, double pathCost) {
        GraphPathSearch.Result<TestVertex, TestEdge> result =
                search.search(graph, src, dst, weight);
        Set<Path<TestVertex, TestEdge>> paths = result.paths();
        printPaths(paths);
        assertEquals("incorrect paths count", pathCount, paths.size());
        if (pathCount > 0) {
            Path<TestVertex, TestEdge> path = paths.iterator().next();
            assertEquals("incorrect path cost", pathCost, path.cost(), 0.1);
        }
    }

}