Learn Junit!

JUnit is a unit testing framework for the Java programming language. JUnit has been important in the development of test-driven development, and is one of a family of unit testing frameworks which is collectively known as xUnit that originated with SUnit. JUnit is linked as a JAR at compile-time; the framework resides under package junit.framework for JUnit 3.8 and earlier, and under package org.junit for JUnit 4 and later. A research survey performed in 2013 across 10,000 Java projects hosted on GitHub found that JUnit (in a tie with slf4j-api), was the most commonly included external library. Each library was used by 30.7% of projects. == Example of JUnit test fixture == A JUnit test fixture is a Java object. With older versions of JUnit, fixtures had to inherit from junit.framework.TestCase, but the new tests using JUnit 4 should not do this. - read more on Wikipedia