Unit Tests

After establishing the schema you can try to store some data in your database. The schema helps to avoid storing wrong or inconsistent data. You can test this behaviour with unit tests.

In your Eclipse project RobotWorldModel execute the following steps:

• Add a new package with name tests.
• Add the library JUnit4 to your project. To do this go to
  Project > Properties > Java Build Path
  and there to the Libraries tab. Click on Add Library, choose JUnit and then JUnit4.
• In the tests package add a new Java class with name LocationTests.
• Add a static method setupBeforeClass(). This method is executed before all tests and hence is used to prepare a proper environment for the tests. The connection to the database is established and all data in the class Location are deleted. Notice: This time a remote connection to the database is used. Hence the server must be running when you execute the tests.

public class LocationTests {
    private static OrientGraph db;
    private static OrientGraphFactory factory;

    @BeforeClass
    public static void setUpBeforeClass() throws Exception {
        factory = new OrientGraphFactory("remote:localhost/RobotWorld1", "admin", "admin"); // The OrientDB server must be running
        db = factory.getTx(); // Connect to the database

        db.command(new OCommandSQL ("delete vertex Location")).execute(); // Delete all Location vertices in the database
    }

• Add a static method teardownAfterClass(). This method is executed after all tests and is used to cleanup the environment. The database connection is shut down and the factory is closed.

    @AfterClass
    public static void tearDownAfterClass() throws Exception {
        db.shutdown();
        factory.close();
    }

• Add a test where you try to store a Position2D without the x-coordinate. This should fail because x is mandatory.

    @Test
    public void testPositionWithoutX() {
        String errorMessage = "";
        Vertex pos = db.addVertex("class:Position");
        pos.setProperty("y", 100);
        pos.setProperty("z", 0);
        try {
            db.commit();
        } catch (Exception e) {
            db.rollback();
            errorMessage = e.getMessage();
        }
        Assert.assertTrue(errorMessage.contains("x' is mandatory"));
    }

• Add a test where you try to store a Location with Name set to NULL. In this test method SQL is used. Again OrientDB should not store this location.

    @Test
    public void testLocationWithoutName () {
        String errorMessage = "";
        try {
            db.command(new OCommandSQL ("insert into Location (Name, Description) values (NULL, 'A location without name')")).execute();
            db.commit();
        } catch (Exception e) {
            db.rollback();
            errorMessage = e.getMessage();
        }
        Assert.assertTrue(errorMessage.contains("Name' cannot be null"));
    }

• Add a test where you try to store a correctly constructed Location together with its shape. This Location should be stored in the database.

    @Test
    public void testLocationOK () {
        long nrLocationsBefore = db.countVertices("Location");
        String errorMessage = "No exception";
        Vertex pos1 = db.addVertex("class:Position", "x", 0, "y", 0, "z", 0);
        Vertex pos2 = db.addVertex("class:Position", "x", 1000, "y", 0, "z", 0);
        Vertex pos3 = db.addVertex("class:Position", "x", 1000, "y", 500, "z", 0);
        Vertex pos4 = db.addVertex("class:Position", "x", 0, "y", 500, "z", 0);

        ArrayList <Vertex> shape = new ArrayList <Vertex> ();
        shape.add(pos1);
        shape.add(pos2);
        shape.add(pos3);
        shape.add(pos4);

        Vertex newLocation = db.addVertex("class:Location");
        newLocation.setProperty("Name", "Extra Room");
        newLocation.setProperty("Description", "This room is not needed. It is an extra room.");
        newLocation.setProperty("shape", shape);

        try {
            db.commit();
        } catch (Exception e) {
            db.rollback();
            errorMessage = e.getMessage();
        }
        long nrLocationsAfter = db.countVertices("Location");
        Assert.assertEquals("No exception", errorMessage);
        Assert.assertEquals(nrLocationsBefore + 1, nrLocationsAfter);
        db.removeVertex(pos1);
        db.removeVertex(pos2);
        db.removeVertex(pos3);
        db.removeVertex(pos4);
        db.removeVertex(newLocation);
        db.commit();
    }

• Start the OrientDB server. Then run your test class. To do this right click on LocationTests.java in the Eclipse package explorer. In the pop up menu choose Run As > JUnit Test. All tests should succeed.

You can download both Java files, CreateDBSchema.java and LocationTests.java, as ZIP-Archive here.