Unit Tests

Learning Objectives

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 behavior with unit tests. In this chapter you will also learn to access the database by a Java program.

Create a new Java Project

Start Eclipse on your computer. In the main menu of eclipse click on File > New > Java Project

A "New Java Project"-dialog opens. Type a name for the project, e.g. CourseParticipation, and choose the default JRE (Java Runtime Environment). Click Next to continue.

In the following "Java Settings"-dialog click on the Libraries tab and then on Add External JARs...

A file dialog opens. Navigate to your orient root directory and then to the jar-directory. Choose the following JAR-files where * is the version number installed on your computer (compare documentation):

blueprints-core-*.jar
concurrentlinkedhashmap-lru-*.jar
jna-*.jar
jna-platform-*.jar
orientdb-client-*.jar
orientdb-core-*.jar
orientdb-enterprise-*.jar
orientdb-graphdb-*.jar

Add the library JUnit4 to your project. To do this click on Add Library, choose JUnit and then JUnit4.

Click Finish - a new empty Java project is created and is added to the list of your Java projects in your workspace. You can see it in the Package Explorer. If it is not visible open it with Window > Show View > Package Explorer

Create a new Package

In the package explorer choose your new project CourseParticipation. Click on the "New Package"-icon or click on File > New > Package in the main menu. In the "New Package"-dialog type the package name tests.

Create a new Java Class for the Unit Tests

In the package explorer choose the newly created package tests. In the main menu click on File > New > Class or click on the "New Java Class"-icon. In the "New Class"-dialog type in the class name e.g. CourseTests.

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. Notice: This time a remote connection to the database is used. Hence the server must be running when you execute the tests.

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

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

Add a test where you try to store a Course without a course number. This should fail because CourseNr is mandatory. We use the Blueprints Tinkerpop API to create a new vertex.

    @Test
    public void testCourseWithoutCourseNr() {
        String errorMessage = "";
        Vertex c = db.addVertex("class:Course");
        pos.setProperty("Subject", "Mathematics");
        try {
            db.commit();
        } catch (Exception e) {
            db.rollback();
            errorMessage = e.getMessage();
        }
        Assert.assertTrue(errorMessage.contains("CourseNr' is mandatory"));
    }

Add a test where you try to store a Course with zero CreditPoints. In this test method SQL is used. Again OrientDB should not store this course.

    @Test
    public void testCourseZeroCreditPoints () {
        String errorMessage = "";
        try {
            db.command(new OCommandSQL ("insert into Course (Subject, CourseNr, CreditPoints) values ('Mathematics', 10001, 0)")).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 Course. This course should be stored in the database.

  @Test
  public void testCourseOk () {
    String errorMessage = "No exception";
    int hits = -1;

    Iterable <Vertex> i = db.command(new OSQLSynchQuery <Vertex> ("select count(*) as hits from Course where Subject = 'TestCourseOk'")).execute();
    for (Vertex count: i) {
      hits = ((Long) count.getProperty("hits")).intValue();
    }
    Assert.assertEquals("Course not in db before",0, hits); // Assert that new course is not yet stored in database
    Vertex c = db.addVertex("class:Course", "Subject", "TestCourseOk", "CourseNr", 30567, "CreditPoints", 5);

    try {
      db.commit();
    } catch (Exception e) {
      db.rollback();
      errorMessage = e.getMessage();
    }
    i = db.command(new OSQLSynchQuery <Vertex> ("select count(*) as hits from Course where Subject = 'TestCourseOk'")).execute();
    for (Vertex count: i) {
      hits = ((Long) count.getProperty("hits")).intValue();
    }
    Assert.assertEquals("No exception", errorMessage);
    Assert.assertEquals("Course in db after insertion", 1, hits);

    db.removeVertex(c);
    db.commit(); 
  }

First make sure that the new course is not yet in the database. To do that query the database for the number of records with Subject equals "TestCourseOk". SQL is used for this query. You can execute SQL queries using the command () method of the database connection. Provide the SQL-string as OSQLSynchQuery object. Since the result is always an Iterable of vertices or edges, even if you expect a number as you would do in this case, you have to iterate the result and retrieve the number with getProperty ("hits").

Then insert the new course with valid data. You can set all the data inside the addVertex() method.

Try to retrieve the newly created course and assert that the query returns 1 as the number of hits this time.

Finally delete the test course. This gives you the possibility to run the test again and again.

Run the Test

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