JUnit expected tag not working as expected

Question

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 1

The problem is that your AnnounceThreadTest 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.

Solution 2

Instead of removing extends TestCase , you can add this to run your test case with Junit4 which supports annotation.

@RunWith(JUnit4.class)

Solution 3

Just ran this in IntelliJ using JUnit 4.4:

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

Passes perfectly.

Rebuild your entire project and try again. There's something else that you're doing wrong. JUnit 4.4 is working as advertised.

Comments

[Torandi]

This one is really weird, did some testing myself, and this code runs fine (the test is successfull)...

[Ben S]

I added a screenshot, just to show... I'd be doubtful too.

[Ben S]

Thank you, this fixed it as advertised.

[burtlo]

After removing the extends TestCase, I had to add the additional import to ensure I had the static assert methods. import static org.junit.Assert.*;

[matt b]

Awesome job at finding the solution hidden as a hint in a screenshot

[Patelify]

Solved!! Thank you, saved me some time.

[Dylan Knowles]

Argggghhhh, I just spent an hour and a half on this issue without finding this answer. Thank you, thank you, thank you!

[Seansms]

The screen shot is a broken link now so we can't see what the original class looked like. I found that if I renamed my class and my tests to no longer start with "test" that suddenly @Begin works and "expected" works too. Thanks Yishai!

[Yishai]

@Seansms, the original screen shot shows that the class extended TestCase. I assume that is your problem as well. Don't extend TestCase, that is the JUnit 3.8 way.