why you should be doing bdd
TRANSCRIPT
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WHY YOU SHOULD BE DOING BDD
MATEUSZ ZALEWSKI
@mpzalewski
https://github.com/Zales0123
BDD is a process designed to aid the management and the delivery of software development projects by improving communication between engineers and
business professionals.
BEHAVIOR DRIVEN DEVELOPMENT
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http://inviqa.com/insights/bdd-guide
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TEST BEHAVIOR
https://worldviewofjesus.files.wordpress.com/2015/02/evolution.jpg
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✦ “There is no time”
✦ “It’s unnecessary extra code”
✦ “I know what I’m writing”
✦ “Client wants visible effect”
✦ and many more…
BENEFITS
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COMMUNICATION
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REQUIREMENTS CODE
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कोड байт
MONEY CODE BYTE
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कोड байт
MONEY CODE BYTE
UBIQUITOUS LANGUAGE
Valu
e
Time
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NOEFFICIENCY
Valu
e
Time
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EFFICIENCY
HOW?
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FAILING
PASSEDREFACTOR
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NO TESTS
NO REFACTORING
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GOAL
We are going to increase sale by
selling more products
We are going to increase sale by
selling more products
GOAL
We are planning to achieve a 10% increase in sale in our web store
in 4 months
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EXAMPLES
Given "PHP T-Shirt" is priced at €100.00
And the store has "VAT" tax rate of 23%
When I add product "PHP T-Shirt" to the cart
Then my cart taxes should be €23.00
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LESS AMBIGUITY =
LESS MISUNDERSTANDINGS
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SPECIFICATION
STORY
How class should work
Application business logic
DON’T TEST, DESCRIBE
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✦ it adds two numbers
✦ it multiplies two numbers
✦ it subtracts two numbers
✦ it divides two numbers
✦ it not allows to divide by 0
WHAT DOES CALCULATOR DO?
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HOW HARD CAN IT BE?
class CalculatorSpec extends ObjectBehavior { function it_adds_two_numbers() { $this->add(4, 5)->shouldReturn(9); }
function it_multiplies_two_numbers() { $this->multiply(3, 8)->shouldReturn(24); } function it_does_not_allow_to_divide_by_0() { $this ->shouldThrow(‘\InvalidArgumentException’) ->during(‘divide’, [10, 0]) ; } }
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class ValidationMessageProviderSpec extends ObjectBehavior { function it_provides_happy_message_if_validation_passed( Validator $validator, ValidatedObject $object ) { $validator->validate($object)->willReturn(true); $this->provide($object)->shouldReturn(‘Great! Everything is fine!’); } }
HAVING FUN WITH MOCKS
THINK IN CODE
CODE IS GOOD
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http://phpsrbija.rs/tday2014/img/portfolio/phpspec.png
STORY
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It is an ancient need to be told stories. But the story needs a great storyteller.
~ Alan Rickman
FEATURE
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WHY? (BUSINESS VALUE)
WHO? (BENEFICIARY)
WHAT? (FEATURE DESCRIPTION)
FEATURE
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In order to pay less while buying goods
As a Customer
I want to receive discount for my purchase
Receiving percentage discount promotion on order
SCENARIO
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Given "PHP T-Shirt" is priced at €100.00
And the store has "VAT" tax rate of 23%
When I add product "PHP T-Shirt" to the cart
Then my cart taxes should be €23.00
BEHAT28
https://github.com/Behat/Behat
✦ uses Gherkin structured language
✦ used to describe application business logic
✦ really impressive
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✦ Behat (PHP)
✦ PHPSpec (PHP)
✦ Cucumber (Ruby)
✦ JBehave (Java)
✦ Spock (Groovy)
✦ SpecFlow (.NET)
TOOLS
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Have no fear of perfection - you’ll never reach it.~ Salvador Dali
THANK YOU
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@mpzalewskihttps://github.com/Zales0123