It should! - BDD in practice

How BDD helps you solve the murder on the Orient Express

Transcript

1. IT SHOULD!
   BDD IN PRACTICE
   

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2. BEHAVIOR DRIVEN DEVELOPMENT
   =
   TEST DRIVEN DEVELOPMENT
   except it's done right
   

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3. TDD
   IS
   CODE-CENTRIC
   WHILE
   BDD
   IS
   COMMUNICATION-CENTRIC
   

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4. IT'S LIKE COKE
   PEPSI
   =
   COCA-COLA
   except it's done right
   

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5. BUT THIS IS NOT ABOUT WHAT BDD MEANS
   THIS IS ALL ABOUT
   TOOLS
   AND ...
   

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6. THE MURDER ON THE ORIENT EXPRESS
   

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7. MA'AM! CAN YOU TEST WHO YOU SAW?
   "What do you mean test? I can describe it if you like" - Ma'am
   ./bin/phpspec desc Suspect
   

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8. THE SUSPECTS
   "He was one of those types, you know"
   - Ma'am
   namespace spec\OrientExpress\Suspect;
   use PhpSpec\ObjectBehavior;
   use Prophecy\Argument;
   class SuspectSpec extends ObjectBehavior
   {
   function it_is_initializable()
   {
   $this->shouldHaveType('OrientExpress\Suspect\Suspect');
   }
   }
   

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9. THE SUSPECTS
   "Don't yell at me! Be a dear and help me out." - Ma'am
   

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10. THE SUSPECTS
    namespace spec\OrientExpress\Suspect;
    use PhpSpec\ObjectBehavior;
    use Prophecy\Argument;
    class SuspectSpec extends ObjectBehavior
    {
    //...
    function it_should_answer_questions()
    {
    $this->answer('Are you the killer?')
    ->shouldReturn('Nope, not me');
    }
    }
    

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11. THE SUSPECTS
    

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12. THE SUSPECTS
    namespace OrientExpress\Suspect;
    class Suspect
    {
    public function answer($question)
    {
    return 'Nope, not me';
    }
    }
    

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13. THE SUSPECTS - REFACTORING MADE EASY
    "Oh, I just remembered!"
    - Ma'am
    namespace spec\OrientExpress\Suspect;
    use PhpSpec\ObjectBehavior;
    use Prophecy\Argument;
    class SuspectSpec extends ObjectBehavior
    {
    // ...
    function it_should_not_confess_to_wrong_questions_if_guilty()
    {
    $this->setGuilty(true);
    $this->answer('Are you the killer?')
    ->shouldReturn('Nope, not me');
    }
    }
    

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14. THE SUSPECTS - REFACTORING MADE EASY
    "Oh, I just remembered!"
    - Ma'am
    namespace spec\OrientExpress\Suspect;
    use PhpSpec\ObjectBehavior;
    use Prophecy\Argument;
    class SuspectSpec extends ObjectBehavior
    {
    // ...
    function it_should_confess_to_key_question_if_guilty()
    {
    $this->setGuilty(true);
    $this->answer('It was you!')
    ->shouldReturn('Mmmkay I confess');
    }
    }
    

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15. THE SUSPECTS
    namespace OrientExpress\Suspect;
    class Suspect
    {
    protected $keyQuestion = 'It was you!';
    protected $guilty = false;
    public function answer($question)
    {
    if ($this->guilty && $question == $this->keyQuestion) {
    return 'Mmmkay I confess';
    }
    return 'Nope, not me';
    }
    // ...
    }
    

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16. SIR! CAN YOU DESCRIBE WHO SOLVED IT?
    ./bin/phpspec desc Detective
    

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17. THE OLDSCHOOL DETECTIVE
    // Oppa PHPUnit style
    function testSolve()
    {
    // ...
    $crime = $this->getMock('OrientExpress\Crime\Crime',
    array('getSuspects'));
    $crime->expects($this->any())
    ->method('getSuspects')
    ->will($this->returnValue(array($suspect1, $suspect2));
    // NoOoOoooOoOoOoo!!!
    }
    

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18. THE DETECTIVE
    class DetectiveSpec extends ObjectBehavior
    {
    // ...
    /**
    * @param OrientExpress\Crime\Crime $crime
    * @param OrientExpress\Suspect\Suspect $suspect1
    * @param OrientExpress\Suspect\Suspect $suspect2
    */
    function it_should_be_able_to_solve_crimes($crime, $suspect1,
    $suspect2)
    {
    $crime->getSuspects()
    ->willReturn(array($suspect1, $suspect2));
    $suspect1->answer('It was you!')
    ->willReturn('Nope, not me');
    $suspect2->answer('It was you!')
    ->willReturn('Mmmkay I confess');
    $this->solve($crime)->shouldReturn($suspect2);
    }
    }
    

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19. THE DETECTIVE
    namespace OrientExpress\Investigators;
    use OrientExpress\Crime\Crime;
    class Detective
    {
    public function solve(Crime $crime)
    {
    foreach ($crime->getSuspects() as $suspect) {
    $answer = $suspect->answer('It was you!');
    if (preg_match('/confess/', $answer)) {
    return $suspect;
    }
    }
    }
    }
    

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20. WORKS AS DESCRIBED
    

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21. WHAT ABOUT THE SCOTLAND YARD?
    

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22. DOES THE POLICE FUNCTION PROPERLY?
    Feature:
    In order to know the crimes on orient express
    As a Scotland Yard API client
    I want to get access to the archives
    

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23. DOES THE POLICE FUNCTION PROPERLY?
    Background:
    Given the following crimes exist:
    | name |
    | "Murder on the Orient Express" |
    And the following detectives exist:
    | name |
    | "Herculse Poirot" |
    And the following suspects exist:
    | name |
    | "Princess Dragomiroff" |
    | "Count Adrenyi" |
    

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24. DOES THE POLICE FUNCTION PROPERLY?
    

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25. Scenario: Getting data from the Scotland Yard's archives
    Given crime "Murder on the Orient Express" was solved by "Hercules P
    oirot"
    And crime "Murder on the Orient Express" had suspects:
    | name |
    | "Princess Dragomiroff" |
    | "Count Adrenyi" |
    When I send GET request to "/api/crimes/ORIENT_EXPRESS_CRIME_ID"
    Then the response should contain json:
    """
    {
    "crime": {
    "name": "Murder on the Orient Express",
    "detective": {
    "name": "Hercules Poirot"
    },
    "suspects": [
    {
    "name": "Princes Dragomiroff"
    },
    {
    "name": "Count Adrenyi"
    }
    ]
    }
    }
    """
    

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26. WHY IS THIS SO IMPORTANT?
    BECAUSE EVERY CODE TELLS A STORY
    OR AT LEAST
    IT SHOULD!
    

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27. ?
    PhpSpec:
    Behat:
    Specs:
    ABOUT ME
    Karol Sójko
    Lead Software Architect @
    Twitter:
    Github:
    https://github.com/phpspec/phpspec
    https://github.com/Behat/Behat
    https://github.com/karolsojko/bdd-in-practice
    Comet Cult
    @karolsojko
    karolsojko
    

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