Testing with JUnit

Testing with JUnit

JUnit is an open source testing framework that comes with Eclipse and other IDEs. You can create JUnit-based classes in the same project as other classes, and use this JUnit code to test the other classes in your project. Using JUnit in this way, you can construct a set of standard tests for everyone working on an application, and if they change the application's code, all they'll need is a few clicks to verify that the application still passes the standard set of tests.

JUnit is designed to test your code, and it's made up of assertion methods that can test various conditions. Here they are:

assertEquals(a, b)

Tests if a is equal to b (a and b are either primitive values or must have an equals method for comparison purposes)

assertFalse(a)

Tests if a is false, where a is a Boolean value

assertNotNull(a)

Tests if a is not null, where a is either an object or null

assertNotSame(a, b)

Tests if a and b both do not refer to the identical object

assertNull(a)

Tests if a is null, where a is either an object or null

assertSame(a, b)

Tests if a and b both refer to the identical object

assertTrue(a)

Tests if a is true, where a is a Boolean value

You construct JUnit tests using these methods; when you run a JUnit application, it opens its own view to give you an immediate indication of which tests have passed and which have failed.