[Junit] Including the parameters in the names of parameterized tests

Junit 4.11 has added the ability to include the name of the parameters in a Parameterized test. This is done by providing a String to the name argument of the @Parameters annotation. Here is an example of a test that uses this feature:

@RunWith(Parameterized.class)
public class AdditionTest 
{
    @Parameters(name="{0} + {1}")
    public static Collection<Object[]> parameters() {
        Object[][] data = new Object[][] {{1, 2, 3}, {0, 3, 3}, {-1, 1, 0}};
        return Arrays.asList(data);
    }
    
    private final int first;
    
    private final int second;
    
    private final int expected;
    
    public AdditionTest(int first, int second, int expected) {
        this.first = first;
        this.second = second;
        this.expected = expected;
    }
    
    @Test
    public void testAddition() {
        Assert.assertThat(first + second, CoreMatchers.is(expected));
    }
}

The arguments are substitued into the numeric arguments of message. In the above example, the tests would be named “testAddition[1 + 2]“, “testAddition[0 + 3]” and “testAddition[-1 + 1]“. Using this feature, you would be able to tell what the parameters were without having to refer back to your unit test code.

Prior to 4.11 the tests would have been named “testAddition[0]“, “testAddition[1]” and “testAddition[2]“, where the 0, 1 and 2 correspond to the index in the Collection that was provided as the parameters – you have to refer back to your unit test code to figure out what the parameters were. If you do NOT specify the name in 4.11, the tests will also be named in this fasion.

Advertisements

2 Responses to [Junit] Including the parameters in the names of parameterized tests

  1. andy says:

    I’ve gotten this to work beautifully on a Mac (OS X 10.7), but cannot get it working on a system running Vista, anybody have suggestions? I’ve tried everything.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: