By writing tests, you're effectively doubling the amount of code you're writing, right? Well, yes and no. Okay, in an extreme case, you might approach double the code. Again, in an extreme case.

In some instances, consulting companies have written unit tests into a contract with a line item and dollar amount attached. Inevitably, this allows the customer the chance to argue to have this line item removed, thus saving them money. This is absolutely the wrong approach. Testing will be done, period, whether manually by the developer running the application to validate her work, by a QA tester, or by an automated suite of tests. Testing is not a line item that can be negotiated or removed (yikes!).

You would never buy an automobile that didn’t pass quality control. Light bulbs must pass inspection. A client, customer, or company will never, ever, save money by foregoing testing. The question becomes, do you write the tests early, while the code is being authored, or manually, at a later date?