Drivers for testing

Drivers for testing are program portions that are used to test the correctness of a class or of a method. The purpose of such drivers is to call all methods of the public interface of a class and verify that they respect the specification.

In order to perform a test that is complete, we should follow some guidelines:

• verify each functionality (each method);
• perform the tests according to a specific order (the order of method application is often important);
• ensure that each statement is executed at least once (for example, when we have a conditional statement, we have to perform the test for various configurations of the input, in such a way that the boolean condition becomes respectively true and false);
• detect and test special cases (for example, an empty file as input to a method that reads from a file).