The testing paradigm

Test-driven development (TDD) is really a way of thinking, or a paradigm if you like, that should be baked into any standard development process. This paradigm starts with tests and drives the momentum of a piece of production code through these tests. TDD means asking the question "How do I know that I have solved the problem?", instead of just "How do I solve the problem?". This is an important idea to grasp. We write code in order to solve a problem, but we should also be able to prove that we have solved the problem through the use of automated tests.

The basic steps of a test-driven approach are as follows:

• Write a test that fails.
• Run the test to ensure that it fails.
• Write code to make the test pass.
• Run the test to see that it now passes.
• Run all tests to see that the new code does not break other tests.
• Repeat.

Using TDD is really a mindset. Some developers follow this approach...