Java Extreme Programming Cookbook

assertXXX( ) Methods

Problem

You want to use the various assertXXX( ) methods to test different conditions.

Solution

junit.framework.TestCase, the base class for all test cases, extends from junit.framework.Assert, which defines numerous overloaded assertXXX( ) methods. Your tests function by calling these methods.

Discussion

Table 4-1 summarizes the various assertXXX( ) methods that can be found in junit.framework.Assert. Although you could get by with using assertTrue( ) for nearly every test, using one of the more specific assertXXX( ) methods often makes your tests more understandable and provides good failure messages. This table is only a summary; each of the methods is overloaded as described shortly.

Table 4-1. Assert method summary

Method	Description
assert( )	This was deprecated in JUnit 3.7 because it interferes with the J2SE 1.4 assert keyword. You should use assertTrue( ) instead. This method was completely removed in JUnit 3.8.
assertEquals( )	Compares two values for equality. The test passes if the values are equal.
assertFalse( )	Evaluates a boolean expression. The test passes if the expression is false.
assertNotNull( )	Compares an object reference to null. The test passes if the reference is not null.
assertNotSame( )	Compares the memory address of two object references using the == operator. The test passes if both refer to different objects.
assertNull( )	Compares an object reference to null. The test passes if the reference is null.