ASPE Test Driven Development.053013

7/27/2019 ASPE Test Driven Development.053013

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Test Driven Development

A Webinar with Kevin Klinemeier


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Kevin Klinemeier

Agile Trainer and Coach

Software Developer / Architect / Tester

@agilekevin

[email protected]


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Agenda

TDD Overview Expected Values

Test Driven Design Additional tools

Getting Started


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TDD

Spend ~3 days writing tests, then start the realwork.

Tell your PMO you need more time

Fire your QA staff: no manual testing orsystem needed


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Unit Testing

Testing of units, by code One class or method

Very few dependencies

Self-determining no interpretation needed


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Categorize the Activity


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Red-green-refactor

CreateaTest

MakeaChange

RunaTest

Refactor

RuntheTest

Pas

Fail

Pass

Fai

Failure is success

Success is the beginning

Change is stability


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Value

Why First?

Why in Agile, whenwe could never

justify it before?Source: Succeeding With Agile: Software Development using Scrum, Mike

Cohn


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Value


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7 Wastes of Software Development

Partially Done WorkExtra Features

RelearningHandoffs

Task Switching

Delays

Defects

Examples of partially donework:

Untested code

Uncoded documentation

Undocumented code

Tests replace documentation

They are TESTS!


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Only develop code thatsatisfies the tests.

Working sets of tests

are a signal to

collaborate & review


RelearningHandoffs

Task Switching

Delays

Defects



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Tests show usagepatterns

Always up-to-date

Facilitates ping-pong-pairing


RelearningHandoffs

Task Switching

Delays

Defects



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Imbedded context

dump

Small tasks minimize

potential forinterruption


RelearningHandoffs

Task Switching

Delays

Defects



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Finds bugs early

Jump-starts defect

resolution to

integration layer


Relearning

Handoffs

Task Switching

Delays

Defects



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Without TDD


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Test Last - Really


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Test Driven Development


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Test Driven Design


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Test Driven Design

How do we make testing cheaper? Design fortestability.

Program to Interfaces

Dependency Injection/IOC

High Cohesion

Low Coupling


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Dynamic MocksRun-time implementation of interfaces

accountService = new AccountService(mockCurrencyService);

mocks = new Mockery();

mockCurrencyService =

mocks.NewMock();

accountService = new AccountService(mockCurrencyService);

Example:We want to test AccountService, but it needs an ICurrencyService.

The concrete ICurrencyService needs lots of stuff.

The ICurrencyService itself has 50 methods.

Expect.Once.On(mockCurrencyService).

Method("GetConversionRate").

With("GBP", "CAD").

Will(Return.Value(2.20));


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Continuous Integration

CI

Server

Integration

Build

Machine

ScriptedBuildIntegra onBuild

Machine

AutomatedUnitTes ng

Transparency&Con nuousBuilds


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Code Coverage

Track progress

Target improvements

Blame your co-

workers


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BDD

System Testing, System Integration Testing, and

GUI Testing: TDD-style

Toolset to parse natural language into automated

actions, execute and report results

Focuses on business-readable input and output.

Maybe even business-writeable.

Given (preconditions)When (actor+action)

Then (observable result)


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Getting Started

PracticeStick with it for at least 3 weeks

Dont go it alone

Measure progress & gaps with code coverage

Expect learning pains


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Your Questions

For any questions we arent

able to cover, Ill beproviding a written response.

Thanks!

Kevin Klinemeier@agilekevin

[email protected]

ASPE Test Driven Development.053013

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