Question

I am running JUnit 4.10 on Eclipse 3.7. I am doing database testing: database used is SQLite3 with sqlitejdbc. I tried running tests on both windows and linux and here are my observations:

• On Windows 7 x64, the tests run faster (~0.6s per test). I do get errors about “Cannot open database file”. They appear to be intermittent (sometimes the same test can pass once while the next run fails)
• On Ubuntu 11.10 x64, the tests are slow (~3s per test). I get errors about “database locked”. Unlike Windows’ errors being intermittent, here, errors seems to happen on the same test/file and once the lock error occur all following tests fails.

UPDATE

You can find the code for tests on GitHub. I think the problem might be something to do with how my @BeforeClass, @Before and test suites are setup

I have a Test Suite like

@RunWith(Suite.class)
@SuiteClasses({ DataAccessTests.class, SimpleQueryTests.class, ... })
public class DataAccessTestSuite {
    @BeforeClass
    public static void setUpDatabase() throws SQLException, ClassNotFoundException {    
        DataAccess.setEnvironment(DataAccess.DATABASE_TESTING);
        Connection conn = DataAccess.getConn();

        // truncate tables: simply DELETE statements
        truncateTables(conn);

        // insert test data, INSERT statements
        insertTestData(conn);
    }

Then in my Test classes I had a @Before that calls setup also.

public class EventsDataAccessTests {

    @Before
public void setup() throws SQLException, ClassNotFoundException {
    DataAccessTestSuite.setUpDatabase();
}

I was thinking I still want to setup my database in case I don’t want to call the entire suite. I think the problem is something to do with this, but I am not sure how exactly it causes a problem. It appears that even if I call the individual test class, my setup for the suite runs? Or if not, how can I insure it is run once in case the test is not called from the Suite?

— Old Post Removed —

Answer 1

You need to make sure no more than one thread at a time tries to have a write-lock on the sqlite database. For an overview of what I mean by that, read

(5) Can multiple applications or multiple instances of the same application access a single database file at the same time?

So when you say:

If I run the test by itself, it passes. When trying to run the whole
suite it fails

I think it’s fair to assume that the write-lock is not released by perhaps a connection object while another one tries to acquire it. So even if you don’t use threads, perhaps the GC doesn’t get to the connection object of a previous test before another test creates another connection object.

Maybe you can post some of these tests to help better understand what might be going wrong.

UPDATE:

Shouldn’t you close the connection here?:

public static void tearDownDatabase() throws SQLException, ClassNotFoundException {
    Connection conn = DataAccess.getConn();
    truncateTables(conn);
}