package graph;

import junit.framework.TestCase;

public class NodeTest extends TestCase
{

    public void testLinkSuccess() throws Exception
    {
        Node root = new Node(1);
        Node n2 = new Node(2);
        assertTrue("The link is successful:\n 1 -> 2",root.link(n2));
        Node n3 = new Node(3);
        assertTrue("The link is successful:\n 1 -> 2 -> 3",n2.link(n3));
    }    
    public void testLinkFail() throws Exception
    {
        Node root = new Node(1);
        Node n2 = new Node(2);
        assertTrue("The link is successful:\n 1 -> 2",root.link(n2));
        Node n3 = new Node(3);
        assertTrue("The link is successful:\n 1 -> 2 -> 3",n2.link(n3));
        assertFalse("The creation of cycle should fail:\n 1 -> 2 -> 3 -> 1",n3.link(root));
    }
    public void testLinkBranchesFail() throws Exception
    {
        Node root = new Node(1);
        Node n2 = new Node(2);
        assertTrue("The link is successful:\n 1 -> 2",root.link(n2));
        Node n3 = new Node(3);
        assertTrue("The link is successful:\n 1 -> 2 -> 3",n2.link(n3));
        
        Node n50 = new Node(50);
        assertTrue("The link is successful:\n 50 -> 2 -> 3, 1 -> 2 -> 3",n50.link(n2));
        assertTrue("The link is successful:\n 50 -> 1 -> 2 -> 3; 50 -> 2 -> 3; 1 -> 2 -> 3",n50.link(root));
        assertFalse("The creation of cycle should fail:\n 3 -> 50 -> 1 -> 2 -> 3; 3 -> 50 -> 2 -> 3; 1 -> 2 -> 3",n3.link(n50)); 
    }
}