GraphTest.java

import org.junit.Test;
import org.junit.Before;
import static org.junit.Assert.assertEquals;

/** Set of Junit tests for our Graph implementations.
 */
public class GraphTest {
    WGraphP4<Character> g;
    GVertex<Character> v, u, x, y;
    WEdge<Character> e, f;

    @Before
    public void setupGraph() {

        g = new WGraphP4<Character>();
        v = new GVertex<Character>('v', g.nextID());
        u = new GVertex<Character>('u', g.nextID());
        x = new GVertex<Character>('x', g.nextID());
        y = new GVertex<Character>('y', g.nextID());
        e = new WEdge<Character>(v, u, 20);
        f = new WEdge<Character>(v, x, 10);
    }

    @Test
    public void testEmpty() {
        assertEquals(0, g.numEdges());
        assertEquals(0, g.numVerts());
    }

    @Test
    public void testAddVertex() {
        assertEquals(true, g.addVertex(v));
        assertEquals(true, g.addVertex(u));
        assertEquals(false, g.addVertex(v));
    }

    @Test
    public void testAddWEdge() {
        assertEquals(true, g.addEdge(e));
        assertEquals(true, g.addEdge(v, x,10));
        assertEquals(false, g.addEdge(v, u,50));
        assertEquals(false, g.addEdge(f));
    }

    @Test
    public void testAdjacency() {
        g.addVertex(v);
        g.addVertex(u);
        g.addVertex(x);
        g.addVertex(y);
        assertEquals(false, g.areAdjacent(u, v));
        g.addEdge(e);
        g.addEdge(f);
        assertEquals(true, g.areAdjacent(u, v));
        assertEquals(true, g.areAdjacent(v, u));
        assertEquals(true, g.areAdjacent(v, x));
        assertEquals(false, g.areAdjacent(x, u));
        assertEquals(false, g.areAdjacent(v, y));
    }

    @Test
    public void testIncidence() {
        g.addVertex(v);
        g.addVertex(u);
        g.addVertex(x);
        g.addVertex(y);
        g.addEdge(e);
        assertEquals(false, g.areIncident(e, x));
        assertEquals(false, g.areIncident(e, y));
        assertEquals(true, g.areIncident(e, v));
        assertEquals(true, g.areIncident(e, u));
        g.addEdge(f);
        assertEquals(true, g.areIncident(f, x));
        assertEquals(false, g.areIncident(f, u));
        assertEquals(4, g.numVerts());
        assertEquals(2, g.numEdges());
    }

    @Test
    public void testDegree() {
        g.addVertex(v);
        g.addVertex(u);
        g.addVertex(x);
        g.addVertex(y);
        assertEquals(0, g.degree(v));
        g.addEdge(e);
        assertEquals(1, g.degree(v));
        g.addEdge(f);
        assertEquals(2, g.degree(v));
        assertEquals(1, g.degree(x));
        assertEquals(0, g.degree(y));
    }


    @Test
    public void testNeighbors() {
        g.addVertex(v);
        g.addVertex(u);
        g.addVertex(x);
        g.addVertex(y);
        assertEquals("[]", g.neighbors(v).toString());
        g.addEdge(e);
        //        System.out.println(g.neighbors(v).toString());
        assertEquals("[1]", g.neighbors(v).toString());
        assertEquals("[0]", g.neighbors(u).toString());
        g.addEdge(f);
        assertEquals("[1, 2]", g.neighbors(v).toString());
        assertEquals("[0]", g.neighbors(u).toString());
        assertEquals("[0]", g.neighbors(x).toString());
        assertEquals("[]", g.neighbors(y).toString());
    }

}