lasse koskela what does it do does it work

(c) 2008 Lasse Koskela

What does it do?Does it work?

QCon London 2008 - An XpDay Sampler

Lasse Koskela

(c) 2008 Lasse Koskela

(c) 2008 Lasse Koskela

(c) 2008 Lasse Koskela

(c) 2008 Lasse Koskela

(c) 2008 Lasse Koskela

What does it do?Does it work?

QCon London 2008 - An XpDay Sampler

Lasse Koskela

(c) 2008 Lasse Koskela

•how do we specify systems?

•how do we test them?

(c) 2008 Lasse Koskela

how do we test systems?

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developer testing bliss

• xUnit frameworks and patterns

• mock object libraries, reflection capabilities

• language as common denominator

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customer testing misery

• no standard toolset

• tooling generally not sufficient

• common denominator?

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surely there are at least some commonalities...

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tools for customer testing

•text vs. tabular

•imperative vs. descriptive

tool systemgluetest

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connecting to the system

• there are certain high-level patterns for

• interacting with the system, and

• observing side effects

(c) 2008 Lasse Koskela

3+2

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1end to end

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2crawling under the skin

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3exercising the internals

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+2

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4stubbing out the irrelevant

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5using testing backdoors

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how do we specify systems?

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analysis

design

implementation

specification

testing

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agile specification

• happens during each iteration

• adds detail incrementally over time

• eventually evolves into automated tests

(c) 2008 Lasse Koskela

tests as specification

• running tests are ultimately the most accurate description of the system (excluding the system itself)

• translation steps between a specification and tests introduces translation errors

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acceptance testdriven development

select feature specify tests

implement feature

automate tests

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who does what?

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when does it happen?

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in other words...

• testers and programmers need to collaborate more closely

• development team and customer need to collaborate more closely

• we need a shared language and medium for doing this!

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we need an interface...

test systemtoolX

...that lets us specify tests in our shared language

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3 guiding principles

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1Avoid turbulent interfaces

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2Focus on meaning

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3Involve people

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thank you