XP talks about two kinds of tests: programmer tests and customer tests. Test-driven programming (also called test-first programming) most commonly refers to the first variety, at least when I use the term. Test-driven programming is letting programmer tests (or unit tests -- again, just a choice of terms) drive the code you write. That means you have to have the test before you write the code. The test drives the code you write by dictating what code you need to write. You write only the code necessary to make your test pass -- no more, no less.

Originally I thought the existence of these unit tests would make functional tests unnecessary. Oops, wrong again. Functional tests and unit tests are vastly different. It took me a long time to understand how they are different and how to use them together to enhance the development process.

Il System testing del software (o dell'hardware) è un testing condotto sul sistema intero per verificare la sua aderenza alle specifiche richieste. Questo tipo di testing è pensato come una black box, ovvero non deve richiedere la conoscenza del design, del codice o della logica interni al sistema.

To make code testing viable, good tool support is needed. This is where PHPUnit comes into play. It is a member of the xUnit family of testing frameworks and provides both a framework that makes the writing of tests easy as well as the functionality to easily run the tests and analyse their results.

Esempio di UnitTest in php.

Agile Database Techniques Test-driven design (TDD), is an evolutionary approach to development which combines test-first development where you write a test before you write just enough production code to fulfill that test and refactoring.

What is the primary goal of TDD? One view is the goal of TDD is specification and not validation. In other words, it’s one way to think through your design before your write your functional code. Another view is that TDD is a programming technique.

Un altro dubbio, a proposito del progressive enhancement, è stato: ok si può usare ajax prendendo determinate precauzioni, ma come faccio a intercettare le diverse idiosincrasie dei diversi  dispositivi che interagiranno con la mia applicazione?

Questo articolo suggerisce una metodologia per testare le nostre applicazioni basata sul test driven design.