Test Driven Development A Tutorial · Title: TDD Tutorial.ppt Author: Erik Doernenburg Subject:...

Test Driven Development

A Tutorial

Erik DörnenburgThoughtWorks

2© Copyright ThoughtWorks, Inc.® 2004-2006

Agenda

• Iteration 0 Tools for test-driven development

• Iteration 1

Test-driven development

• Iteration 2

Interaction-based testing

• Iteration 3

Lightweight containers


The four XP values

Simplicity

Communication

Feedback

Courage

Iteration 0Tools for test-driven development


Core tools for TDD

an IDE a unit testing frameworka build automation tool a continuous integration system

Iteration 1 Test-driven development


Iteration 1

As a wallet owner I would

like to be able to put money

into my wallet so that I can

take it out later.

#1


Iteration 1


like to be able to see how

much money is in my wallet.

#2


Iteration 1


like to be able to take a

specified amount of money

out of the wallet.

#3


[Switch to development environment]


Iteration 1


like to be able to take out

more money than I have, so

that I can buy things I

can't afford.

account#3b



Iteration 2Interaction-based testing


Collaborating Objects

• An object-oriented program is organised as a web of collaborating objects


Using Mocks

• To isolate the tested object we replace its neighbours with mock objects

Object under test

Test case

Mock

Mock


Iteration 2

As an auditor I would like

to be notified whenever an

account is overdrawn.

#4





#4

Iteration 2

Task 1:

Introduce AccountService

#4.1





#4

Iteration 2

Task 2:

Add audit service and logic

#4.2


Iteration 2

As an account owner I

would like be notified by

email when I overdraw my

account.

#5


Iteration 2


to be notified whenever

more than £10,000 are

withdrawn from an account

in one transaction.

#6



Iteration 3Lightweight containers


Iteration 3

Where is my application?


PicoContainer

pico containerclasses objects




Iteration 3

What’s this ‘Inversion of Control’thing people are talking about?


Dependency resolution

• Service Locator

• Dependency Injection

Service Locator

Dependency Injector




Iteration 3

But we’re using the Spring framework!

Odds and endsObject Mother


Odds and ends

My tests are ugly!



The end

Test Driven Development A Tutorial · Title: TDD Tutorial.ppt Author: Erik Doernenburg Subject:...

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