BDD DPC 2014 Tutorial

Behave! - BDD

DPC 2014

Tobias Schlitt (@tobySen)

2014-06-26

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☑ Unit Tests ☑ Selenium

No, no, no …!

Some time later…

Behavior Driven Development (BDD)

I

Executable specification

I

Combines

I

Test Driven Development

I

Business communication

I

Common language

I

Business people

I

Analysts

I

Developers

I

Testers

Outline

Behat

Mink

Conclusion

Behat

I

BDD test framework for PHP

I

Inspired by Ruby’s Cucumber

I

Work with Gherkin language framework

Gherkin

I

Domain Specific Language (DSL) framework

I

Goal: Business readable

I

Create custom DSL on Gherkin

Gherkin in Action

1 Feature: DateTime proceeds t o end o f month. 2

3 Scenario: End o f February i s reached 4 Given i t i s date ”2013−02

−01”

5 When I proceed t o t h e end o f t h e month 6 Then t h e date i s ”2013

−02−28”

Gherkin keywords

I

Given

I

_Precondition

I

_{Test setup}

I

When

I

Behavior trigger

I

Test stimulus

I

Then

I

Expected behavior

I

Describe observable result

I

And

/

But

Binding Code to Sentences

1 Feature: DateTime proceeds t o end o f month.

2

3 Scenario: End o f February i s reached 4 Given i t i s date ”2013−02−01”

5 When I proceed t o t h e end o f t h e month 6 Then t h e date i s ”2013−02−28”

1 class ExampleContext extends BehatContext

2 {

Binding Code to Sentences

1 Feature: DateTime proceeds t o end o f month.

2

3 Scenario: End o f February i s reached 4 Given i t i s date ”2013−02−01”

5 When I proceed t o t h e end o f t h e month 6 Then t h e date i s ”2013−02−28”

1 class ExampleContext extends BehatContext

2 { 3 protected $date; 4 5 /∗ ∗ 6 ∗ @Given / ˆ i t i s date ” ( [ ˆ ” ]∗) ” $ / 7 ∗/ 8 p u b l i c f u n c t i o n t h e r e I s T h e D a t e($date) 9 {

10 $ t h i s−>date = new \DateTime($date) ;

11 }

Binding Code to Sentences

1 Feature: DateTime proceeds t o end o f month.

2

3 Scenario: End o f February i s reached 4 Given i t i s date ”2013−02−01”

5 When I proceed t o t h e end o f t h e month 6 Then t h e date i s ”2013−02−28”

1 class ExampleContext extends BehatContext

2 {

3 /∗ ∗

4 ∗ @When / ˆ I proceed t o t h e end o f t h e month$ /

5 ∗/

6 p u b l i c f u n c t i o n iProceedToTheEndOfTheMonth( )

7 {

8 $ t h i s−>date−>m o d i f y(” l a s t day o f t h i s month ”) ;

9 }

Binding Code to Sentences

1 Feature: DateTime proceeds t o end o f month.

2

3 Scenario: End o f February i s reached 4 Given i t i s date ”2013−02−01”

5 When I proceed t o t h e end o f t h e month 6 Then t h e date i s ”2013−02−28”

1 class ExampleContext extends BehatContext

2 {

3 /∗ ∗

4 ∗ @Then / ˆ t h e date i s ” ( ? P<date>[ ˆ ” ]∗) ” $ /

5 ∗/

6 p u b l i c f u n c t i o n theDateIsNow($date)

7 {

8 \PHPUnit Framework Assert: :a s s e r t E q u a l s(

9 $date,

10 $ t h i s−>date−>f o r m a t(” Y−m−d ”)

11 ) ;

12 }

Using Behat

I

$ path/to/behat[.phar]

Command for Behat usage

I

$ behat --init

Initialize global test infrastructure

I

$ behat --init @SomeNiceBundle

Initialize bundle test infrastructure

I

$ behat -dl

Display known sentences

I

$ behat path/to/features

Execute feature tests in directory

I

$ behat @SomeNiceBundle

Behavior Driven Development

Model

Domain

DDD

Domain Driven Design

Ubiquitous Language

DSL

Domain Specific Language

Speci

fi

cation

BDD

Outline

Behat

Mink

Mink

I

Web acceptance test framework

I

Abstracts browser emulations / controllers

I

Goutte

I

_Zombie.js

I

_{Selenium / Selenium 2}

I

_Sahi

I

Mink extension for Behat provides sentences

Behat Mink Example

1 Feature: Browse W i k i p e d i a 2

3 Scenario: Search f r o n t page 4 Given I am on ” / ”

5 When I f i l l i n ”s e a r c h I n p u t” w i t h ”Kore” 6 And I pr es s ”s e a r c h B u t t o n”

7 Then I s h o u l d see ”Kore may r e f e r t o: ” 8

9 Scenario: F o l l o w r e d i r e c t l i n k 10 Given I am on ” / ”

11 When I f i l l i n ”s e a r c h I n p u t” w i t h ”Kore” 12 And I pr es s ”s e a r c h B u t t o n”

13 And I f o l l o w ”Kore (energy d r i n k) ”

Mink Behat-extension

I

Mink integration for Behat

I

Pre-build sentences to browse pages

I

Extensible with custom sentences

Attention!

I

This is no more BDD!

I

Too technical

I

Not bound to the model

I

Fragile for view changes

I

However

I

_{Useful for system tests}

I

_{Awesome for refactoring!}

BDD through the Front-End

1 /

∗ ∗

2

∗

@Given / ˆ I am logged i n as ” ( [ ˆ ” ]

∗

) ” $ / 3

∗

/ 4 p u b l i c f u n c t i o n iAmLoggedInAs($user) 5

{

6 $ t h i s

−

>

currentUsername = $user; 7 8 r e t u r n a r r a y(

9 new Step

\

Given(’ I am on ” / ” ’) ,

10 new Step

\

When(’ I f i l l i n ” username ” w i t h ” ’ .

$user . ’ ” ’) ,

11 new Step

\

When(’ I f i l l i n ” password ” w i t h ” t e s t ” ’) , 12 new Step

\

When(’ I p re ss ” Log in ” ’) ,

13 ) ;

Outline

Behat

Mink

Unit Testing?

I

The hype is over

I

Still important for

I

Complexity

I

High impact code

Double Feedback Test Cycle

Project Owner Failing Acceptance Test Developer Failing Unit-Test Make Test Pass Refactor Make Test Pass

Test Mix Aspects

Coverage

Stability

Unit Tests Functional Tests Acceptance Tests Integration Tests

Conclusion

I

BDD makes specification executable

I

_{Awesome for communication}

I

_{Awesome to abuse for front-end testing (Mink)}

I

_{No low hanging fruit}

I

Easy to fail

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