maven-resolver-util/src/test/java/org/eclipse/aether/util/graph/visitor/TreeDependencyVisitorTest.java

package org.eclipse.aether.util.graph.visitor;

/*
 * 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.
 */

import static org.junit.Assert.*;

import org.eclipse.aether.graph.DependencyNode;
import org.eclipse.aether.graph.DependencyVisitor;
import org.eclipse.aether.internal.test.util.DependencyGraphParser;
import org.junit.Test;

public class TreeDependencyVisitorTest
{

    private DependencyNode parse( String resource )
        throws Exception
    {
        return new DependencyGraphParser( "visitor/tree/" ).parseResource( resource );
    }

    @Test
    public void testDuplicateSuppression()
        throws Exception
    {
        DependencyNode root = parse( "cycles.txt" );

        RecordingVisitor rec = new RecordingVisitor();
        TreeDependencyVisitor visitor = new TreeDependencyVisitor( rec );
        root.accept( visitor );

        assertEquals( ">a >b >c <c <b >d <d <a ", rec.buffer.toString() );
    }

    private static class RecordingVisitor
        implements DependencyVisitor
    {

        StringBuilder buffer = new StringBuilder( 256 );

        public boolean visitEnter( DependencyNode node )
        {
            buffer.append( '>' ).append( node.getDependency().getArtifact().getArtifactId() ).append( ' ' );
            return true;
        }

        public boolean visitLeave( DependencyNode node )
        {
            buffer.append( '<' ).append( node.getDependency().getArtifact().getArtifactId() ).append( ' ' );
            return true;
        }

    }

}