Question

I have a bunch of JUnit 3 classes which extend TestCase and would like to automatically migrate them to be JUnit4 tests with annotations such as @Before, @After, @Test, etc.
Any tool out there to do this in a big batch run?

Answer 1

In my opinion, it cannot be that hard. So let’s try it:

0. Imports

You need to import three annotations:

import org.junit.After; import org.junit.Before; import org.junit.Test;` 

After you’ve made the next few changes, you won’t need import junit.framework.TestCase;.

1. Annotate test* Methods

All methods beginning with public void test must be preceded by the @Test annotation. This task is easy with a regex.

2. Annotate SetUp and TearDown methods

Eclipse generates following setUp() method:

@Override protected void setUp() throws Exception { } 

Must be replaced by:

@Before public void setUp() throws Exception { } 

Same for tearDown():

@Override protected void tearDown() throws Exception { } 

replaced by

@After public void tearDown() throws Exception { } 

3. Get rid of extends TestCase

Remove exactly one occurence per file of the string

' extends TestCase' 

4. Remove main methods?

Probably it’s necessary to remove/refactor existing main methods that will execute the test.

5. Convert suite() method to @RunWithClass

According to saua’s comment, there must be a conversion of the suite() method. Thanks, saua!

@RunWith(Suite.class) @Suite.SuiteClasses({   TestDog.class   TestCat.class   TestAardvark.class }) 

Conclusion

I think, it’s done very easy via a set of regular expressions, even if it will kill my brain 😉