differences between 2 JUnit Assert classes

Question

Hi,

I've noticed that the JUnit framework contains 2 Assert classes (in different packages, obviously) and the methods on each appear to be very similar. Can anybody explain why this is?

The classes I'm referring to are: junit.framework.Assert and org.junit.Assert.

Cheers, Don

Answer 1

I believe they are refactoring from junit.framework to org.junit and junit.framework.Assert is maintained for backwards compatibility.

Answer 2

The old method (of Junit 3) was to mark the test-classes by extending junit.framework.TestCase. That inherited junit.framework.Assert itself and your test-class gained the ability to call the assert-methods this way.

Since version 4 of junit the framework uses Annotations for marking tests. So you no longer need to extend TestCase. But that means, the assert-methods aren't available. But you can make a static import of the new Assert-class. That's why all the assert-methods in the new class are static methods. So you can import it this way:

import static org.junit.Assert.*;

After this static import, you can use this methods without prefix.

At the redesign they also moved to the new package org.junit, that follows better the normal conventions for package-naming.

Answer 3

JUnit 3.X: junit.framework.Assert JUnit 4.X: org.junit.Assert

Prefer the newest one, especially when running JDK5 and higher with annotation support.

Answer 4

I did a rough source code compare and there are no serious changes.

Lot of comments were added in org.junit.Assert and some refactorings are done.

The only change is the comparison with Arrays. There are some code clean ups, but there's (imho) no functional change.

Answer 5

There is in fact a functional change: org.junit.Assert will complain if you use the two-argument assertEquals() with float or double, while junit.framework.Assert will silently autobox it.