Question

I want to do some automated datastore tests for the Google App Engine locally with Junit.

I have written a class ‘Agent.java’ with three Strings ‘name’, ‘owner’ and ‘url’. The class ‘Player’ is abstract, but does not provide additional attributes.

public class Agent extends Player implements Serializable {

/** to serialize Agent */
private static final long serialVersionUID = -6859912740484191335L;

/** The name of the Agent is the key-element of the agent-class*/
@Id String name;
/** Url to the Agent */
String url;

@Index String owner;
...

Followed by Setters and Getters.

I have copied the 4 needed library from the sdk 1.6.0 to the projects ‘war/WEB-INF/lib’ folder and included the Junit4 Container.

My test class looks like this:

import static org.junit.Assert.*;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.logging.Logger;

import org.junit.BeforeClass;
import org.junit.AfterClass;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import com.google.appengine.api.datastore.DatastoreService;
import com.google.appengine.api.datastore.DatastoreServiceFactory;
import com.google.appengine.api.datastore.Entity;
import com.google.appengine.api.datastore.Query;
import com.google.appengine.api.datastore.Query.FilterOperator;
import com.google.appengine.tools.development.testing.LocalDatastoreServiceTestConfig;
import com.google.appengine.tools.development.testing.LocalServiceTestHelper;
import com.google.code.twig.annotation.AnnotationObjectDatastore;

public class AgentContrTest {

private static final Logger log = Logger.getLogger("AgentContrTest.class");

private static UserController uc;   
private static GameController gc;
private static AgentController ac;

private static final LocalServiceTestHelper helper =
        new LocalServiceTestHelper(new LocalDatastoreServiceTestConfig());

private  AnnotationObjectDatastore datastore = new AnnotationObjectDatastore(false);    


@BeforeClass 
public static void setUpOnce()  {

    gc = GameController.getInstance();
    uc = UserController.getInstance();
    ac = AgentController.getInstance();

}

@Before
public void setUp()  {
    helper.setUp();
    try {
        uc.register("userForTest", "test", "[e-mail]", false);

    }
     catch (NameExistsException ne) {
     }
    catch (EmailFormatException ee) {
     }
}

 @After
 public void tearDown() {
  helper.tearDown();
}

 // Testing the raising of NameExistsException in createAgent(String name, String url, String owner)
 @Test(expected=NameExistsException.class)
 public void testCreateAgentExc1() throws NameExistsException {

     Agent ag1 = ac.createAgent("Agent1", "www.agent1.com", "Owner1");
     Agent ag2 = ac.createAgent("Agent1", "www.agent2.com", "Owner2"); 
 }

// Testing getAgents()
@Test
public void testGetAgents1() throws NameExistsException {
    datastore.disassociateAll();
    ArrayList<Agent> agents1 = ac.getAgents();

    ac.createAgent("Agent1", "www.agent1.com", "Owner1");
    ac.createAgent("Agent2", "www.agent2.com", "Owner2"); 
    ac.createAgent("Agent3", "www.agent3.com", "userForTest"); 

    ArrayList<Agent> agents2 = ac.getAgents();

    assertTrue(agents1.size()==0);
    assertTrue(agents2.size()==3);
    datastore.disassociateAll();
 }

 // Testing getAgents(String user)
 @Test
 public void testGetAgents2() throws NameExistsException {
   ArrayList<Agent> agents = ac.getAgents();
   assertTrue(agents.size()==0);
   datastore.disassociateAll(); 

   ac.createAgent("Agent1", "www.agent1.com", "Owner1");
   ac.createAgent("Agent2", "www.agent2.com", "Owner2"); 
   ac.createAgent("Agent3", "www.agent3.com", "userForTest"); 


   ArrayList<Agent> agents2 = ac.getAgents("userForTest");

   assertTrue(agents2.size()==1);
 }

These are the functions in my AgentController that I am testing:

public ArrayList<Agent> getAgents(String user) {

    ArrayList<Agent> agents = new ArrayList<Agent>();

    Iterator<Agent> agentIterator = datastore.find().type(Agent.class)
            .addFilter("owner", FilterOperator.EQUAL, user)
            .now();

    while (agentIterator.hasNext()) {
        agents.add(agentIterator.next());
    }

    return agents;

}

public Agent createAgent(String name, String url, String owner) throws NameExistsException {

    Agent agent = datastore.load(Agent.class, name);
    if (agent != null)
        throw new NameExistsException();

    agent = new Agent();
    agent.setName(name);
    agent.setUrl(url);
    agent.setOwner(owner);

    datastore.store(agent);

    return agent;

}

The testCreateAgentExc1 is working just fine. But the testGetAgents2() is throwing a NameExistsException, which it should not do. If i rename the agents in this test to ‘Agent4’ to ‘Agent6’ it is working just fine.

Due to ‘http://code.google.com/intl/de-DE/appengine/docs/java/tools/localunittesting.html‘
the Datastore should delete all data between the tests, so the NameExistsException should not be raised.

Answer 1

You are not resetting your datastore object between tests. I’m not sure how twig works, but it (or its configuration) is the cause of the leak.