Test Driven Development: By Example

Appendix II. Fibonacci

In answer to a question from one of the reviewers of this book, I posted a test-driven Fibonacci. Several reviewers commented that this example turned on their light about how TDD works. However, it is not long enough, nor does it demonstrate enough of TDD techniques, to replace the existing examples. If your lights are still dark after reading the main examples, take a look here and see.

The first test shows that fib(0) = 0. The implementation returns a constant.

public void testFibonacci() {
					assertEquals(0, fib(0));
					}

int fib(int n) {
   return 0;
					}
				

(I am just using the TestCase class as a home for the code, because it is only a single function.)

The second test shows that fib(1) = 1.

public void testFibonacci() ...