Java contract test helpers

Certain code you override or implement is expected to adhere to contracts laid out in the Java SDK. Examples of these are:

• equals method: http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html#equals(java.lang.Object)
• hashcode method: http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html#hashCode()
• Comparable interface: http://docs.oracle.com/javase/7/docs/api/java/lang/Comparable.html
• Serializable interface: http://docs.oracle.com/javase/7/docs/api/java/io/Serializable.html

A project called junit-addons on SourceForge has test superclasses that enable compliance testing of objects to these java contracts

• http://junit-addons.sourceforge.net/junitx/extensions/package-frame.html

Although these test helper classes work without issue, they are designed for pre-generic java, and JUnit 3.x and could be confusing to developers used to JUnit 4.x annotations style of test implementation.

The project Equals Verifier provides support for testing equals and hashCode.