JUnit testing - Whats wrong with a test that`s expected result should be passed?

Question

I am testing a simple thing in my DB-Application. To create a product. For this I use Junit tests and here is the test that always fail, instead the expected result to turn green(passes)...

@Test
public void testCreate(){
    Produkt test = new Produkt(20, "junit", "junitk", false, 900.67, true, true);
    handler.createProdukt(test);
}

when I try it out simply with a main method(just creating a new Produkt and look if that works...) the create function works great and created this Produkt.

What am I doing wrong?

PS.: here is the code where I set up the tests:

@Before
public void setUp() throws SQLException, ClassNotFoundException{
    try {
        this.shandler = new ServiceHandler();
        this.setServiceHandler(shandler);
        manager.getConnection();
        manager.getConnection().setAutoCommit(false);
    } catch (SQLException ex) {
        System.err.println("ERROR:");
        ex.printStackTrace();
    }

}

@After
public void tearDown() throws SQLException, ClassNotFoundException{
    manager.getConnection().rollback();
    manager.closeConnection();
}

UPDATE I guess you mean the failure trace:

java.lang.NullPointerException at tests.JUnitAbstractTests.testCreate(JUnitAbstractTests.java:35) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20) at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47) at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222) at org.junit.runners.ParentRunner.run(ParentRunner.java:300) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50) at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

"the test that always fails" how does it fail? Exception? Not expected output? does not terminate? .... — assylias
+1 to @assylias. In addition how do you run the test with the main method? Do you perform the test setup as JUnit does? Do you call setUp() in your main? — AlexR
You shouldn't catch exceptions in your @Before method like that. If a SQLException is thrown by the objects you are setting up, you are allowing the test to proceed. — matt b

matt b matt b · Accepted Answer · 2012-09-27T15:51:01

Assuming your code snippets are accurate, your setUp() method instantiates a shandler field while your testCreate() test uses a handler field. And the stacktrace clearly shows that you have a NullPointerException in testCreate(). So the thing that you are doing wrong is trying to call a method on an object whose value is null.

JUnit testing - Whats wrong with a test that`s expected result should be passed?

1 Answers