JUnit expected tag not working as expected

Issue

I have the following test case in eclipse, using JUnit 4 which is refusing to pass. What could be wrong?

@Test(expected = IllegalArgumentException.class)
public void testIAE() {
    throw new IllegalArgumentException();
}

This exact testcase came about when trying to test my own code with the expected tag didn't work. I wanted to see if JUnit would pass the most basic test. It didn't.

I've also tested with custom exceptions as expected without luck.

Screenshot:

Solution

The problem is that your nnounceThreadTest extends TestCase. Because it extends TestCase, the JUnit Runner is treating it as a JUnit 3.8 test, and the test is running because it starts with the word test, hiding the fact that the @Test annotiation is in fact not being used at all.

To fix this, remove the extends TestCase from the class definition.

Answered By - Yishai