by @_mdPHPUK 2014

Test, Transform,

Refactor

TEST,

REFACTOR

Test, Transform,

Refactor

Test, Transform,

Refactor

Test, Transform,Refactor

TRANSFORM,

@_md Marcello Duarte

Lead developer

Head of Training Kata sensei

Learning

@_md Marcello Duarte

Lead developer

Head of Training

Kata

formmovementpracticedeliberate

Kata

20 minutesthrow away

TDDrefactor

Test

CodeRefactor

3Rules

no code without test

enough to go red

enough to go greenTDD

no code without test

enough to go red

enough to go green

Test

Code

4Rules

tests run and passdryremove opacitySimple Design

simplify

Refactor

The Roman Numerals Kata

Converting arabic numbers into their roman equivalent

!

e.g. 2149 => MMCXLIX

Test

Code

Refactor

Make it red

Make it green

Make it right

The Roman Numerals Kata gone wrong demo

Introducing TPP

Test

Transform

Refactor

Make it more specific

Make it more generic

Put on the design hat

Transformations (just the most basic ones)

null to constantconstant to constant+constant to scalarstatement to statementsunconditional to ifif to while

Jim Weirich’s Roman Numeral Kata*

http://www.flickr.com/photos/jorendegroof/4471189540/

* in PHP

Walking skeleton

[Cockburn 94]

Transformation null -> constant

Transformation null -> constant

Transformation unconditional -> if

Transformation unconditional -> if

Transformation statement -> statements

Transformation statement -> statements

Transformation unconditional -> if

Transformation unconditional -> if

Refactor time?

Transformation if -> while

Transformation if -> while

Condition to loop transformation !

is a great indicator you are in the right track of solving the algorithm

[Martin 13]

Katas and Learning

Kata Deliberate Practice

Koan Deliberate Learning

• Optimising for performance • Minimising variance

• Optimising for discovery • Maximising variance

[North 12]

Learning TDD is learning all that TDD does for you

“The beauty of a move lies not in its' appearance but in the thought behind it.”

My Systemelements of chess

positional play

illustrative games

First learn the elements of design Then learn how to drive it with test

we are hiring try phpspec!

follow @_md

Marcello Duarte

inviqa.com/tdd-immersion-day/

Thank you !

Questions or Comments?

want to learn more? inviqa.com/tdd-immersion-day/

@_mdjoind.in/10711