Specification by Example

Specification by example What? How? When?

Marcus Hammarberg

http://www.youtube.com/aptitudsthlm

Bandung

Theory of Constraints

Where is our bottleneck?

http://images.nationalgeographic.com/wpf/media-live/photos/000/212/cache/sinkholes-holes-ground-2007-guatemala-sinkhole_21282_600x450.jpg

Deliberate Discovery

Gojko Adzic

... it’s no silver bullet, but it seems

like a good start

Dan North

http://manning.com/adzic/From Specification by Example

Used with permission

http://www.wallpaperpimper.com/wallpaper/Military/F_16_Fighting_Falcon/F-16-Fighting-Falcon-20-9XTZMAN20G-1280x1024.jpg

http://www.wallpaperpimper.com/wallpaper/Military/F_16_Fighting_Falcon/F-16-Fighting-Falcon-20-9XTZMAN20G-1280x1024.jpg

Who sets scope?

http://2.bp.blogspot.com/-mJ8gPBlBRjY/TcYv9xOuWlI/AAAAAAAAKvY/0JniIDxlBjY/s1600/how-to-get-your-boss-off-your-back.jpg

How do they know what they want?

How do they know what they want?

Don’t let the customer

limit themselves

http://www.realestateradiousa.com/blog/wp-content/uploads/2008/09/straitjacket.jpg

Derive scope from business goals

http://cojent7.files.wordpress.com/2010/04/business-goals1.jpg

Build the right thing!

§

1. Start with wide end of it on your right and extending a foot below the narrow end 2. Cross wide end over narrow and turn back underneath 3. Bring up and turn down to loop 4. Pass wide end around frong from left to right 5. Then, up through loop ... 6. And down through knot in front. Tigthen carefully and draw up to collar.

Go concrete with exampleshttp://www.flickr.com/photos/bensutherland/3961418687/

Scenario 1: Account is in credit!Given the account is in credit!And the card is valid!And the dispenser contains cash!When the customer requests €50!Then ! ensure the account is debited €50!And ensure €40 is dispensed!And ensure the card is returned

Key examples

Key examples

http://www.bigideastobigresults.com/wp-content/uploads/2009/09/good_enough.jpg

Let’s try that, shall we?

Customers who buys three books gets free shipping

Customers who buys three books gets free shipping

Number of books Free shipping?

Customers who buys three books gets free shipping

Number of books Free shipping?1 -

Customers who buys three books gets free shipping

Number of books Free shipping?

21

--

Customers who buys three books gets free shipping

Number of books Free shipping?

23

1-X

-

Customers who buys three books gets free shipping

Number of books Free shipping?

234

1-XX

-

To get a loan you need to be older than 18

To get a loan you need to be older than 18

Age of applicant Can take loan?

To get a loan you need to be older than 18

Age of applicant Can take loan?17 -

To get a loan you need to be older than 18

Age of applicant Can take loan?

1817

X-

To get a loan you need to be older than 18

Age of applicant Can take loan?

1819

17XX

-

To get a loan you need to be older than 18

Age of applicant Can take loan?

1819null?

17XXeeeeh?

-

http://www.flickr.com/photos/toastytreat/4555895229

Text

Who writes this stuff anyway?

Refactor the specification

Examples should be precise and testable

Examples should be precise and testable

Scripts are not specifications

Examples should be precise and testable

Scripts are not specifications

Specifications should be about business functionality, not software design

Examples should be precise and testable

Scripts are not specifications

Specifications should be about business functionality, not software design

Specifications should be self-explanatory

Examples should be precise and testable

Scripts are not specifications

Specifications should be about business functionality, not software design

Specifications should be self-explanatory

Specifications should be in domain language

Sharedunderstanding

Sharedunderstanding

Testing

Sharedunderstanding

Testing

Documentation

Automation

http://jbehave.org/reference/stable/images/jbehave-logo.png

http://lh5.ggpht.com/_X3kaawac_g4/S0nxyUKaIYI/AAAAAAAAAu0/CtKaMavsxoM/cucumber.jpg?imgmax=800

http://lh6.ggpht.com/_X3kaawac_g4/SuoT1Yd67pI/AAAAAAAAArU/dhE-WLR0VKE/Unbenannt.png?imgmax=800

A Cucumber ScenarioScenario 1: Account is in credit!Given the account is in credit!And the card is valid!And the dispenser contains cash!When the customer requests €50!Then ! ensure the account is debited €50!And ensure €50 is dispensed!And ensure the card is returned

http://1.bp.blogspot.com/-3yjyeeTpRFI/Tea15VHttaI/AAAAAAAAC3w/YXoTDAv9tx8/s1600/hard_work.png

One document to rule them all ...

http://www.questpartnership.co.uk/blog/uploaded_images/restructuring-775119.jpg

“... features are an executable map of the current functionality of the system.”

Andrew Premdas (BDD Google Group)

ToC and Specification by example

ToC and Specification by example

• Better communication

ToC and Specification by example

• Better communication

• Concrete examples

ToC and Specification by example

• Better communication

• Concrete examples

• Frequent validation

ToC and Specification by example

• Better communication

• Concrete examples

• Frequent validation

• Living documentation

Learn more

Learn more

Learn more

Learn more

Learn more

Learn more

www.marcusoft.net @marcusoftnet

[email protected]

www.marcusoft.net @marcusoftnet

[email protected]

Recording of this talk http://www.youtube.com/

aptitudsthlm