testdriven%development - udl...
TRANSCRIPT
Test Driven Development
So#ware Quality Quality Audit and Cer6fica6on
Master in Computer Engineering
Roberto García ([email protected])
Introduc6on
• Tes6ng is the most popular quality-‐improvement ac6vity.
• SoGware is tested in numerous ways, some performed by developers and others by specialized test personnel.
• Simplest developer tes:ng: – Unit tes:ng: the execu6on of a complete class, rou6ne or small program. • WriOen by a single programmer or team of programmers. • Tested in isola:on from the complete system.
Introduc6on
• Design the test cases along with the product to find defects as early as possible
• Advantages of wri6ng test cases first: – Detect defects earlier. – Forces to think at least a liOle bit about the requirements and design before wri6ng code.
– Wri6ng test cases first exposes requirements problems sooner because it's hard to write a test case for a poor requirement.
Introduc6on
• Test-‐driven development (TDD) is a development technique where you must first write a test that fails before you write new func6onal code.
• Complementary to Agile development – Methods based on itera:ve and incremental development, where requirements and solu6ons evolve
• Not a replacement for tradi6onal tes6ng, a proven way to ensure effec6ve unit tes6ng.
Introduc6on
• TDD requires a tes:ng framework. • OGen the xUnit family of open source tools – JUnit: the framework for Java
• TDD encourages small steps when wri6ng soGware – It is much easier to find, and then fix, defects
Learning-‐by-‐doing
• Kata (型 or 形 literally: "form”) – Thee Japanese word describing detailed choreographed paOerns of movements to be prac6sed.
Learning-‐by-‐doing
• The Bowling Game Kata – hOp://butunclebob.com/Ar6cleS.UncleBob.TheBowlingGameKata
– A kata is meant to be memorized. – It is not the conclusion of the kata that maOers, it's the steps that lead to the conclusion.
– As you learn the form, and repeat it, and repeat it, you will condi6on your mind and body to respond the way I respond to the minute factors that lead to design decisions.
– I have broken the kata up into five short sec:ons. Fully learn one sec:on before adding the next.
– Don't learn the next un6l you have mastered the previous. A kata needs to seep into your bones, and this take 6me.
Learning-‐by-‐doing
• The Bowling Game Kata – Presenta6on: hOp://butunclebob.com/files/downloads/Bowling%20Game%20Kata.ppt • Addi:onal resources: “Bowling Game Kata.ppt”
– Videos: • hOp://www.youtube.com/watch?v=2PfXbKIDbKw (C#, Visual Studio) • hOp://www.youtube.com/watch?v=igywEzPJRsM (Java, Eclipse)
Exercise
• First of all, master the “Bowling Game Kata” ;-‐)
• For your mini-‐project, try to develop at least one component using the TDD approach – Using xUnit, for instance JUnit in Java
• Addi:onal resources: “AES’11-‐12_Tes6ng.pdf”