Tests Should Tell a Story

Given at Laracon US 2016.

Transcript

1. TESTS SHOULD TELL A STORY
   LARACON US 2016
   

   View Slide

2. STORIES
   

   View Slide

3. WHO KNOWS THIS MAN?
   

   View Slide

4. FRED ROGERS
   

   View Slide

5. THE NEIGHBORHOOD LIVES ON
   

   View Slide

6. We live in a world in which
   we need to share
   responsibility.
   It's easy to say, “It's not my
   child, not my community,
   not my world, not my
   problem.”
   Then there are those who
   see the need and respond. I
   consider those people my
   heroes.
   Fred Rogers
   

   View Slide

7. TAYLOR OTWELL
   

   View Slide

8. View Slide

9. View Slide

10. View Slide

11. View Slide

12. YOUR CODE
    TELLS A STORY
    

    View Slide

13. View Slide

14. TESTS SHOULD TELL A STORY
    DISTILLED SHARED KNOWLEDGE
    ▸ Good naming
    ▸ Good abstractions
    ▸ Details pushed down
    ▸ Intent clearly expressed
    ▸ Test driven (mostly)
    

    View Slide

15. TESTS SHOULD TELL A STORY
    IN STORY FORM
    ▸ Who are the characters? (Subject & Collaborators)
    ▸ What is the setting? (Environment)
    ▸ What is the plot? (Goal of our system)
    ▸ What is the conflict? (Task at hand)
    ▸ What is the resolution? (Solution)
    

    View Slide

16. STORIES ARE NOT JUST TOLD
    THEY ARE INTERPRETED
    

    View Slide

17. I NEED MAYO
    Coheed and Cambria
    HEADSHOT KID DISASTER FROM SECOND STAGE TURBINE BLADE
    

    View Slide

18. WHAT DO YOU SEE?
    

    View Slide

19. View Slide

20. EVEN FUTURE-YOU WILL
    INTERPRET CODE DIFFERENTLY
    

    View Slide

21. TESTS SHOULD TELL A STORY
    COMMUNICATIVE CONCERNS TO CONSIDER
    ▸ Skill level
    ▸ Ambiguous intent
    ▸ Cultural differences
    ▸ Language differences
    ▸ Contextual differences
    ▸ Mood at the time of reading
    ▸ Knowledge of area/domain of code
    

    View Slide

22. View Slide

23. TESTS SHOULD TELL A STORY
    EXPECTATIONS
    ▸ Ex: A method named read in a CSV parsing library
    ▸ Load the entire file into memory into an array
    ▸ Stream the file, each line as an array
    ▸ Load the file into a lazily evaluated collection - each row
    lazily loaded in an array
    

    View Slide

24. AMBIGUITY LEAVES ROOM FOR
    INTERPRETATION
    

    View Slide

25. We don’t make
    mistakes, we
    have happy
    accidents.
    Bob Ross
    

    View Slide

26. WE ARE NOT BOB ROSS
    

    View Slide

27. WE MAKE MISTAKES
    

    View Slide

28. OUR MISTAKES HAVE
    CONSEQUENCES
    

    View Slide

29. WRITE TESTS
    TO PREVENT HAPPY ACCIDENTS
    

    View Slide

30. YOU DO WRITE TESTS, DON’T YOU?
    

    View Slide

31. ಠ_ಠ
    

    View Slide

32. ಠ_ಠ
    

    View Slide

33. ಠ_ಠ
    

    View Slide

34. View Slide

35. KEYNOTE !"
    

    View Slide

36. View Slide

37. TESTS
    

    View Slide

38. ANATOMY OF A TEST
    

    View Slide

39. TESTS SHOULD TELL A STORY
    ANATOMY OF A TEST - FOUR PHASE
    ▸ Setup environment and preconditions
    ▸ Exercise the method/system under test
    ▸ Verify the result
    ▸ Tear down the environment
    

    View Slide

40. TESTS SHOULD TELL A STORY
    ANATOMY OF A TEST - AAA
    ▸ Arrange preconditions and input
    ▸ Act on the object/method/system under test
    ▸ Assert what you expect the result to be
    

    View Slide

41. TESTS SHOULD TELL A STORY
    ANATOMY OF A TEST - GIVEN-WHEN-THEN
    ▸ Arrange - Given
    ▸ Act - When
    ▸ Assert - Then
    

    View Slide

42. SETTING A BASELINE
    

    View Slide

43. TESTS SHOULD TELL A STORY
    PHPUNIT
    class UserRepositoryTest extends PHPUnit_Framework_TestCase {
    public function setup() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    }
    public function teardown() {
    $this->subject->clear();
    }
    public function testCanFindAUserByName() {
    $user = $this->subject->findByName($this->name);
    $this->assertEquals($this->name, $user->name);
    }
    }
    

    View Slide

44. XUNIT
    

    View Slide

45. TESTS SHOULD TELL A STORY
    XUNIT - PHPUNIT
    class UserRepositoryTest extends PHPUnit_Framework_TestCase {
    public function setup() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    }
    public function teardown() {
    $this->subject->clear();
    }
    public function testCanFindAUserByName() {
    $user = $this->subject->findByName($this->name);
    $this->assertEquals($this->name, $user->name);
    }
    }
    

    View Slide

46. TESTS SHOULD TELL A STORY
    XUNIT - PHPUNIT
    class UserRepositoryTest extends PHPUnit_Framework_TestCase {
    public function setup() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    }
    public function teardown() {
    $this->subject->clear();
    }
    public function testCanFindAUserByName() {
    $user = $this->subject->findByName($this->name);
    $this->assertEquals($this->name, $user->name);
    }
    }
    

    View Slide

47. TESTS SHOULD TELL A STORY
    XUNIT - PHPUNIT
    class UserRepositoryTest extends PHPUnit_Framework_TestCase {
    public function setup() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    }
    public function teardown() {
    $this->subject->clear();
    }
    public function testCanFindAUserByName() {
    $user = $this->subject->findByName($this->name);
    $this->assertEquals($this->name, $user->name);
    }
    }
    

    View Slide

48. TESTS SHOULD TELL A STORY
    XUNIT - PHPUNIT
    class UserRepositoryTest extends PHPUnit_Framework_TestCase {
    public function setup() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    }
    public function teardown() {
    $this->subject->clear();
    }
    public function testCanFindAUserByName() {
    $user = $this->subject->findByName($this->name);
    $this->assertEquals($this->name, $user->name);
    }
    }
    

    View Slide

49. TESTS SHOULD TELL A STORY
    XUNIT - PHPUNIT
    class UserRepositoryTest extends PHPUnit_Framework_TestCase {
    public function setup() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    }
    public function teardown() {
    $this->subject->clear();
    }
    public function testCanFindAUserByName() {
    $user = $this->subject->findByName($this->name);
    $this->assertEquals($this->name, $user->name);
    }
    }
    

    View Slide

50. TESTS SHOULD TELL A STORY
    XUNIT - PHPUNIT
    class UserRepositoryTest extends PHPUnit_Framework_TestCase {
    public function setup() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    }
    public function teardown() {
    $this->subject->clear();
    }
    public function testCanFindAUserByName() {
    $user = $this->subject->findByName($this->name);
    $this->assertEquals($this->name, $user->name);
    }
    }
    

    View Slide

51. TESTS SHOULD TELL A STORY
    XUNIT - PHPUNIT
    class UserRepositoryTest extends PHPUnit_Framework_TestCase {
    public function setup() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    }
    public function teardown() {
    $this->subject->clear();
    }
    public function testCanFindAUserByName() {
    $user = $this->subject->findByName($this->name);
    $this->assertEquals($this->name, $user->name);
    }
    }
    

    View Slide

52. TESTS SHOULD TELL A STORY
    XUNIT - PHPUNIT
    class UserRepositoryTest extends PHPUnit_Framework_TestCase {
    public function setup() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    }
    public function teardown() {
    $this->subject->clear();
    }
    public function testCanFindAUserByName() {
    $user = $this->subject->findByName($this->name);
    $this->assertEquals($this->name, $user->name);
    }
    }
    

    View Slide

53. SPEC/BDD STYLE
    

    View Slide

54. AT A BASIC LEVEL
    VERY SIMILAR
    

    View Slide

55. TESTS SHOULD TELL A STORY
    XUNIT - PHPUNIT
    class UserRepositoryTest extends PHPUnit_Framework_TestCase {
    public function setup() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    }
    public function teardown() {
    $this->subject->clear();
    }
    public function testCanFindAUserByName() {
    $user = $this->subject->findByName($this->name);
    $this->assertEquals($this->name, $user->name);
    }
    }
    

    View Slide

56. TESTS SHOULD TELL A STORY
    SPEC/BDD - PHO
    describe(‘A User Repository’, function() {
    beforeEach(function() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    });
    afterEach(function() {
    $this->subject->clear();
    });
    it(‘can find a user by name’, function() {
    $user = $this->subject->findByName($this->name);
    expect($user->name)->toEqual($this->name);
    });
    });
    

    View Slide

57. TESTS SHOULD TELL A STORY
    XUNIT - PHPUNIT
    class UserRepositoryTest extends PHPUnit_Framework_TestCase {
    public function setup() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    }
    public function teardown() {
    $this->subject->clear();
    }
    public function testCanFindAUserByName() {
    $user = $this->subject->findByName($this->name);
    $this->assertEquals($this->name, $user->name);
    }
    }
    

    View Slide

58. TESTS SHOULD TELL A STORY
    SPEC/BDD - PHO
    describe(‘A User Repository’, function() {
    beforeEach(function() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    });
    afterEach(function() {
    $this->subject->clear();
    });
    it(‘can find a user by name’, function() {
    $user = $this->subject->findByName($this->name);
    expect($user->name)->toEqual($this->name);
    });
    });
    

    View Slide

59. TESTS SHOULD TELL A STORY
    SPEC/BDD - PHO
    describe(‘A User Repository’, function() {
    beforeEach(function() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    });
    afterEach(function() {
    $this->subject->clear();
    });
    it(‘can find a user by name’, function() {
    $user = $this->subject->findByName($this->name);
    expect($user->name)->toEqual($this->name);
    });
    });
    

    View Slide

60. TESTS SHOULD TELL A STORY
    SPEC/BDD - PHO
    describe(‘A User Repository’, function() {
    beforeEach(function() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    });
    afterEach(function() {
    $this->subject->clear();
    });
    it(‘can find a user by name’, function() {
    $user = $this->subject->findByName($this->name);
    expect($user->name)->toEqual($this->name);
    });
    });
    

    View Slide

61. TESTS SHOULD TELL A STORY
    SPEC/BDD - PHO
    describe(‘A User Repository’, function() {
    beforeEach(function() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    });
    afterEach(function() {
    $this->subject->clear();
    });
    it(‘can find a user by name’, function() {
    $user = $this->subject->findByName($this->name);
    expect($user->name)->toEqual($this->name);
    });
    });
    

    View Slide

62. TESTS SHOULD TELL A STORY
    SPEC/BDD - PHO
    describe(‘A User Repository’, function() {
    beforeEach(function() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    });
    afterEach(function() {
    $this->subject->clear();
    });
    it(‘can find a user by name’, function() {
    $user = $this->subject->findByName($this->name);
    expect($user->name)->toEqual($this->name);
    });
    });
    

    View Slide

63. TESTS SHOULD TELL A STORY
    SPEC/BDD - PHO
    describe(‘A User Repository’, function() {
    beforeEach(function() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    });
    afterEach(function() {
    $this->subject->clear();
    });
    it(‘can find a user by name’, function() {
    $user = $this->subject->findByName($this->name);
    expect($user->name)->toEqual($this->name);
    });
    });
    

    View Slide

64. TESTS SHOULD TELL A STORY
    SPEC/BDD - PHO
    describe(‘A User Repository’, function() {
    beforeEach(function() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    });
    afterEach(function() {
    $this->subject->clear();
    });
    it(‘can find a user by name’, function() {
    $user = $this->subject->findByName($this->name);
    expect($user->name)->toEqual($this->name);
    });
    });
    

    View Slide

65. TESTS SHOULD TELL A STORY
    SPEC/BDD - PHO
    describe(‘A User Repository’, function() {
    beforeEach(function() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    });
    afterEach(function() {
    $this->subject->clear();
    });
    it(‘can find a user by name’, function() {
    $user = $this->subject->findByName($this->name);
    expect($user->name)->toEqual($this->name);
    });
    });
    

    View Slide

66. TESTS SHOULD TELL A STORY
    SPEC/BDD - PHO
    describe(‘A User Repository’, function() {
    beforeEach(function() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    });
    afterEach(function() {
    $this->subject->clear();
    });
    it(‘can find a user by name’, function() {
    $user = $this->subject->findByName($this->name);
    expect($user->name)->toEqual($this->name);
    });
    });
    

    View Slide

67. TESTS SHOULD TELL A STORY
    NESTED CONTEXTS
    describe(‘A User Repository’, function() {
    beforeEach(function() {
    $this->subject = new UserRepository();
    $this->name = ‘Machuga’;
    $this->subject->save(new User($this->name));
    });
    afterEach(function() {
    $this->subject->clear();
    });
    context(‘when finding a user’, function() {
    it(‘can find an existing user by name’, function() {
    $user = $this->subject->findByName($this->name);
    expect($user->name)->toEqual($this->name);
    });
    it(‘returns null when given an invalid name’, function() {
    $user = $this->subject->findByName(‘Santa Claus’);
    expect($user)->toEqual(null);
    });
    });
    });
    

    View Slide

68. TESTS SHOULD TELL A STORY
    SPEC OR DOCUMENTATION FORMATTER PRINTS AS
    A User Repository
    when finding a user
    can find an existing user by name
    returns null when given an invalid username
    

    View Slide

69. TESTS SHOULD TELL A STORY
    SUBJECTIVE PREFERENCE TO BDD SPECS OVER XUNIT
    ▸ Generally written out in sentences
    ▸ Easily mapped to user stories
    ▸ Easily mapped to acceptance criteria
    ▸ Easily readable by stakeholders
    ▸ Allow for contexts to be described easily
    ▸ Allow for nested contexts
    ▸ Handles multiple cases well
    ▸ I work with them day-to-day
    

    View Slide

70. HOW ARE YOU FEELING
    ABOUT THE SPEC DSL?
    

    View Slide

71. HOW ARE YOU FEELING
    ABOUT THE SPEC DSL?
    

    View Slide

72. SPEC LIBRARIES
    WE’LL BE USING
    

    View Slide

73. SPEC LIBRARIES
    WE’LL BE USING
    

    View Slide

74. JASMINE
    &
    RSPEC
    

    View Slide

75. TESTS SHOULD TELL A STORY
    JASMINE
    describe(‘A User Repository’, function() {
    const subject = new UserRepository();
    const name = ‘Machuga’;
    beforeEach(function() {
    subject.save(new User(name));
    });
    afterEach(function() {
    subject.clear();
    });
    it(‘can find a user by name’, function() {
    const user = subject.findByName(name);
    expect(user.name).toEqual(name);
    });
    });
    

    View Slide

76. TESTS SHOULD TELL A STORY
    JASMINE
    describe(‘A User Repository’, function() {
    const subject = new UserRepository();
    const name = ‘Machuga’;
    beforeEach(function() {
    subject.save(new User(name));
    });
    afterEach(function() {
    subject.clear();
    });
    it(‘can find a user by name’, function() {
    const user = subject.findByName(name);
    expect(user.name).toEqual(name);
    });
    });
    const defines a variable
    that cannot be redefined
    

    View Slide

77. TESTS SHOULD TELL A STORY
    JASMINE
    describe(‘A User Repository’, function() {
    const subject = new UserRepository();
    const name = ‘Machuga’;
    beforeEach(function() {
    subject.save(new User(name));
    });
    afterEach(function() {
    subject.clear();
    });
    it(‘can find a user by name’, function() {
    const user = subject.findByName(name);
    expect(user.name).toEqual(name);
    });
    });
    dot syntax rather than ->
    

    View Slide

78. TESTS SHOULD TELL A STORY
    JASMINE
    describe(‘A User Repository’, function() {
    const subject = new UserRepository();
    const name = ‘Machuga’;
    beforeEach(function() {
    subject.save(new User(name));
    });
    afterEach(function() {
    subject.clear();
    });
    it(‘can find a user by name’, function() {
    const user = subject.findByName(name);
    expect(user.name).toEqual(name);
    });
    });
    lexical scope for variables
    

    View Slide

79. TESTS SHOULD TELL A STORY
    RSPEC
    describe ‘A User Repository’ do
    subject { UserRepository.new }
    let(:name) { ‘Machuga’ }
    before do
    subject.save(User.new(name))
    end
    after do
    subject.clear!
    end
    it ‘can find a user by name’ do
    user = subject.find_by_name(name)
    expect(user.name).to eq(name)
    end
    end
    

    View Slide

80. TESTS SHOULD TELL A STORY
    RSPEC
    describe ‘A User Repository’ do
    subject { UserRepository.new }
    let(:name) { ‘Machuga’ }
    before do
    subject.save(User.new(name))
    end
    after do
    subject.clear!
    end
    it ‘can find a user by name’ do
    user = subject.find_by_name(name)
    expect(user.name).to eq(name)
    end
    end
    blocks denoted by { } or do..end
    

    View Slide

81. TESTS SHOULD TELL A STORY
    RSPEC
    describe ‘A User Repository’ do
    subject { UserRepository.new }
    let(:name) { ‘Machuga’ }
    before do
    subject.save(User.new(name))
    end
    after do
    subject.clear!
    end
    it ‘can find a user by name’ do
    user = subject.find_by_name(name)
    expect(user.name).to eq(name)
    end
    end
    optional syntax
    

    View Slide

82. TESTS SHOULD TELL A STORY
    RSPEC
    describe ‘A User Repository’ do
    subject { UserRepository.new }
    let(:name) { ‘Machuga’ }
    before do
    subject.save(User.new(name))
    end
    after do
    subject.clear!
    end
    it ‘can find a user by name’ do
    user = subject.find_by_name(name)
    expect(user.name).to eq(name)
    end
    end
    new is a method on the class
    

    View Slide

83. TESTS SHOULD TELL A STORY
    RSPEC
    describe ‘A User Repository’ do
    subject { UserRepository.new }
    let(:name) { ‘Machuga’ }
    before do
    subject.save(User.new(name))
    end
    after do
    subject.clear!
    end
    it ‘can find a user by name’ do
    user = subject.find_by_name(name)
    expect(user.name).to eq(name)
    end
    end
    can use ! and ? in method names
    

    View Slide

84. 5 TIPS FOR SPEC
    STORYTELLING
    OR: I TRIED THESE 5 WEIRD TRICKS ON MY TESTS;
    YOU’LL NEVER GUESS WHAT HAPPENED NEXT!
    

    View Slide

85. 1. BE EXPRESSIVE
    

    View Slide

86. CUSTOM ACTIONS
    FOR COMPLEX BEHAVIOR
    

    View Slide

87. TESTS SHOULD TELL A STORY
    RSPEC ACCEPTANCE TEST
    describe 'items' do

    it 'should be able to be dragged into categories' do

    drag_item_to_category_with_text 'apple', 'a-f'
    expect('apple').to be_in_category_with_text(‘a-f')

    end

    end
    

    View Slide

88. TESTS SHOULD TELL A STORY
    LAYOUT
    CHECK NEXT
    

    View Slide

89. TESTS SHOULD TELL A STORY
    LAYOUT
    CHECK NEXT
    

    View Slide

90. TESTS SHOULD TELL A STORY
    RSPEC CUSTOM ACTION
    # Perform drag and drop on item by name to category by name

    def drag_item_to_category_with_text(item_text, category_text)

    item(item_text).drag_to category_with_text(category_text)

    end
    

    View Slide

91. TESTS SHOULD TELL A STORY
    RSPEC CUSTOM ACTION
    # Perform drag and drop on item by name to category by name

    def drag_item_to_category_with_text(item_text, category_text)

    item(item_text).drag_to category_with_text(category_text)

    end
    

    def item(text)

    sel = “#{item_prefix}_categorizable_selector”

    page.find(send(sel), text: text)

    end
    

    def category_with_text(text)

    sel = “#{category_prefix}_category_selector”

    page.find(send(sel), text: text)

    end
    

    View Slide

92. TESTS SHOULD TELL A STORY
    RSPEC ACCEPTANCE TEST REPRISE
    describe 'items' do

    it 'should be able to be dragged into categories' do

    drag_item_to_category_with_text 'apple', 'a-f'
    expect('apple').to be_in_category_with_text(‘a-f')

    end

    end
    

    View Slide

93. TESTS SHOULD TELL A STORY
    RSPEC ACCEPTANCE TEST UNFOLDED
    describe 'items' do

    it 'should be able to be dragged into categories' do

    item = page.find(

    send(#{item_prefix}_categorizable_selector”),

    text: ‘apple’)

    category = page.find(

    send(“#{category_prefix}_category_selector”),

    text: ‘a-f’)

    

    item.drag_to category
    expect('apple').to be_in_category_with_text(‘a-f')

    end

    end
    

    View Slide

94. TESTS SHOULD TELL A STORY
    RSPEC ACCEPTANCE TEST DOUBLED DOWN
    describe 'items' do
    it 'should be able to be dragged into categories' do

    item1 = page.find(

    send("#{item_prefix}_categorizable_selector"),

    text: 'apple')
    item2 = page.find(

    send("#{item_prefix}_categorizable_selector"),

    text: 'oranges')
    item3 = page.find(

    send("#{item_prefix}_categorizable_selector"),

    text: 'bananas')
    item4 = page.find(

    send("#{item_prefix}_categorizable_selector"),

    text: 'kiwis')
    category = page.find(

    send('#{category_prefix}_category_selector'),

    text: 'a-f')

    item1.drag_to category
    item2.drag_to category
    item3.drag_to category
    item4.drag_to category
    expect(uncategorized_items).to be_empty

    end

    end
    

    View Slide

95. TESTS SHOULD TELL A STORY
    RSPEC ACCEPTANCE TEST DOUBLED DOWN
    describe 'items' do
    it 'should be able to be dragged into categories' do

    item1 = page.find(

    send("#{item_prefix}_categorizable_selector"),

    text: 'apple')
    item2 = page.find(

    send("#{item_prefix}_categorizable_selector"),

    text: 'oranges')
    item3 = page.find(

    send("#{item_prefix}_categorizable_selector"),

    text: 'bananas')
    item4 = page.find(

    send("#{item_prefix}_categorizable_selector"),

    text: 'kiwis')
    category = page.find(

    send('#{category_prefix}_category_selector'),

    text: 'a-f')

    item1.drag_to category
    item2.drag_to category
    item3.drag_to category
    item4.drag_to category
    expect(uncategorized_items).to be_empty

    end

    end
    

    View Slide

96. TESTS SHOULD TELL A STORY
    RSPEC ACCEPTANCE TEST NOPE
    describe 'items' do
    it 'should be able to be dragged into categories' do

    item1 = page.find(

    send("#{item_prefix}_categorizable_selector"),

    text: 'apple')
    item2 = page.find(

    send("#{item_prefix}_categorizable_selector"),

    text: 'oranges')
    item3 = page.find(

    send("#{item_prefix}_categorizable_selector"),

    text: 'bananas')
    item4 = page.find(

    send("#{item_prefix}_categorizable_selector"),

    text: 'kiwis')
    category1 = page.find(

    send('#{category_prefix}_category_selector'),

    text: 'a-f')

    category2 = page.find(

    send('#{category_prefix}_category_selector'),

    text: 'g-n')

    category3 = page.find(

    send('#{category_prefix}_category_selector'),

    text: 'o-w')

    category4 = page.find(

    send('#{category_prefix}_category_selector'),

    text: 'x-z')

    item1.drag_to category1
    item2.drag_to category2
    item3.drag_to category3
    item4.drag_to category4
    check_button.click
    expect(next_button).to be_enabled

    end

    end
    

    View Slide

97. TESTS SHOULD TELL A STORY
    RSPEC ACCEPTANCE TEST NOPE
    describe 'items' do
    it 'should be able to be dragged into categories' do

    item1 = page.find(

    send("#{item_prefix}_categorizable_selector"),

    text: 'apple')
    item2 = page.find(

    send("#{item_prefix}_categorizable_selector"),

    text: 'oranges')
    item3 = page.find(

    send("#{item_prefix}_categorizable_selector"),

    text: 'bananas')
    item4 = page.find(

    send("#{item_prefix}_categorizable_selector"),

    text: 'kiwis')
    category1 = page.find(

    send('#{category_prefix}_category_selector'),

    text: 'a-f')

    category2 = page.find(

    send('#{category_prefix}_category_selector'),

    text: 'g-n')

    category3 = page.find(

    send('#{category_prefix}_category_selector'),

    text: 'o-w')

    category4 = page.find(

    send('#{category_prefix}_category_selector'),

    text: 'x-z')

    item1.drag_to category1
    item2.drag_to category2
    item3.drag_to category3
    item4.drag_to category4
    check_button.click
    expect(next_button).to be_enabled

    end

    end
    

    View Slide

98. TESTS ARE CODE
    REFACTOR!
    

    View Slide

99. USE THE BEST
    MATCHER / ASSERTION
    

    View Slide

100. expect((2+2).to_s == 4).to eq true
     

     View Slide

101. Failures:
     1) Hi, Laracon! #
     Failure/Error: expect((2+2).to_s == 4).to eq true
     expected true
     got false
     (compared using ==)
     # ./testing_spec.rb:3:in `block (2 levels) in '
     Finished in 0.02861 seconds (files took 0.16021 seconds to load)
     1 example, 1 failure
     Failed examples:
     rspec ./testing_spec.rb:2 # My awesome example group works
     

     View Slide

102. expect((2+2).to_s).to eq 4
     

     View Slide

103. Failures:
     1) Hi, Laracon! #
     Failure/Error: expect((2+2).to_s).to eq 4
     expected: 4
     got: "4"
     (compared using ==)
     # ./testing_spec.rb:3:in `block (2 levels) in '
     Finished in 0.01195 seconds (files took 0.13384 seconds to load)
     1 example, 1 failure
     Failed examples:
     rspec ./testing_spec.rb:2 # My awesome example group works
     

     View Slide

104. CUSTOM
     MATCHERS / ASSERTIONS
     

     View Slide

105. TESTS SHOULD TELL A STORY
     LARAVEL CUSTOM ASSERTION
     /**
     * Asserts that the response contains the given header
     * and equals the optional value.
     *
     * @param string $headerName
     * @param mixed $value
     * @return $this
     */
     protected function seeHeader($headerName, $value = null)
     {
     $headers = $this->response->headers;
     $this->assertTrue($headers->has($headerName), "Header [{$headerName}] not present on
     response.");
     if (! is_null($value)) {
     $this->assertEquals(
     $headers->get($headerName), $value,
     "Header [{$headerName}] was found, but value [{$headers->get($headerName)}] does
     not match [{$value}]."
     );
     }
     return $this;
     }
     

     View Slide

106. TESTS SHOULD TELL A STORY
     PHPUNIT CUSTOM ASSERTIONS BLESSED METHOD
     use PHPUnit\Framework\TestCase;
     abstract class PHPUnit_Framework_Assert {
     public static function assertTrue($condition, $message = ‘') {
     self::assertThat($condition, self::isTrue(), $message);
     }
     public static function isTrue()
     {
     return new PHPUnit_Framework_Constraint_IsTrue;
     }
     }
     class PHPUnit_Framework_Constraint_IsTrue extends PHPUnit_Framework_Constraint {
     public function matches($other) {
     return $other === true;
     }
     public function toString() {
     return 'is true';
     }
     }
     

     View Slide

107. TESTS SHOULD TELL A STORY
     RSPEC CUSTOM MATCHER
     require 'rspec/expectations'
     RSpec::Matchers.define :be_a_multiple_of do |expected|
     match do |actual|
     actual % expected == 0
     end
     failure_message do |actual|
     "expected that #{actual} would be a multiple of #{expected}"
     end
     end
     RSpec.describe 9 do
     it ‘should blow up and be helpful’ do
     expect(9).to be_a_multiple_of(4)
     end
     end
     Failures:
     1) 9 should blow up and be helpful
     Failure/Error: expect(9).to be_a_multiple_of(4)
     expected that 9 would be a multiple of 4
     

     View Slide

108. 2. RESPECT THE CUKES
     

     View Slide

109. TESTS SHOULD TELL A STORY
     CUCUMBER
     

     View Slide

110. TESTS SHOULD TELL A STORY
     USER STORIES AS GHERKIN SPECS
     Feature: Getting Laracon attendees test their code
     In order to convince Laracon attendees to test their code

     As a speaker

     I want to provide helpful information and entertainment
     Scenario: Adam Wathan gives a TDD talk prior to my talk

     Given that attendees recently saw Adam’s talk

     And I was in the audience

     When I go to give my talk

     Then I can make some assumptions on what attendees know

     And I can weep as a rearrange my slide deck
     

     View Slide

111. TESTS SHOULD TELL A STORY
     USER STORIES AS RSPEC SPECS
     describe ‘Convincing Laracon attendees to test their code’ do
     describe ‘Giving a talk as a speaker’ do
     context ‘Adam Wathan gives a TDD talk the day before’ do
     it ‘can make some assumptions on what attendees know’
     it ‘can weep while rearranging slide deck’
     end
     end
     end
     

     View Slide

112. TESTS SHOULD TELL A STORY
     BEHAVIOR-DRIVEN DEVELOPMENT
     ‣ Describing/designing an application as how it appears to the
     stakeholder
     ‣ Feature-driven workflow
     ‣ Embraces concepts of the Agile Manifesto
     ‣ Individuals and interactions over processes and tools
     ‣ Working software over comprehensive documentation
     ‣ Customer collaboration over contract negotiation
     ‣ Responding to change over following a plan
     

     View Slide

113. 3. BAD STORIES ARE SIGNALS
     

     View Slide

114. TESTS SHOULD TELL A STORY
     SMELLS OF BAD STORIES
     ▸ Plot holes
     ▸ Lack of Character Development
     ▸ No Descriptions
     ▸ Switching narrative
     

     View Slide

115. TESTS SHOULD TELL A STORY
     PLOT HOLES
     ▸ Mocking the object under test
     ▸ Global state mutations out of view
     ▸ Implicit Behavior
     

     View Slide

116. TESTS SHOULD TELL A STORY
     NO DESCRIPTIONS
     ▸ Creating abstractions that provide no benefit
     ▸ No explanation why the environment is in current state
     ▸ The world is bland and empty
     

     View Slide

117. TESTS SHOULD TELL A STORY
     LACK OF CHARACTER DEVELOPMENT
     ▸ Performing transformations on characters out of view
     ▸ Mocking collaborators without clear reason
     

     View Slide

118. TESTS SHOULD TELL A STORY
     SWITCHING NARRATIVES
     ▸ Setting expectations on collaborators
     ▸ Blurring lines between suites
     

     View Slide

119. 4. UNIT TEST IN ISOLATION
     

     View Slide

120. MORE ON THIS SOON
     

     View Slide

121. 5. TRY TDD/BDD
     

     View Slide

122. TWO WEEKS
     

     View Slide

123. TESTS SHOULD TELL A STORY
     FEATURE-FIRST
     ▸ Build only what your client needs at that moment
     ▸ Supports slice plans
     ▸ Waste few resources to test an idea
     ▸ Provides readable, agreed upon specs for stakeholders
     ▸ Encourages collaboration
     

     View Slide

124. TESTS SHOULD TELL A STORY
     DRIVING YOUR DESIGN & CODE
     

     View Slide

125. TESTS SHOULD TELL A STORY
     DRIVING YOUR DESIGN & CODE
     ▸ Write failing test first
     ▸ Evidence feature is incomplete
     ▸ Evidence feature is not coincidently passing
     

     View Slide

126. TESTS SHOULD TELL A STORY
     DRIVING YOUR DESIGN & CODE
     ▸ Write failing test first
     ▸ Evidence feature is incomplete
     ▸ Evidence feature is not coincidently passing
     ▸ Write smallest amount of code
     ▸ Evidence necessary code to solve that use-case is implemented
     

     View Slide

127. TESTS SHOULD TELL A STORY
     DRIVING YOUR DESIGN & CODE
     ▸ Write failing test first
     ▸ Evidence feature is incomplete
     ▸ Evidence feature is not coincidently passing
     ▸ Write smallest amount of code
     ▸ Evidence necessary code to solve that use-case is implemented
     ▸ Listen to feedback & refactor code & test in pieces
     ▸ Confidence nothing is broken
     ▸ Aids in better design
     

     View Slide

128. TESTS SHOULD TELL A STORY
     DRIVING YOUR DESIGN & CODE
     ▸ Write failing test first
     ▸ Evidence feature is incomplete
     ▸ Evidence feature is not coincidently passing
     ▸ Write smallest amount of code
     ▸ Evidence necessary code to solve that use-case is implemented
     ▸ Listen to feedback & refactor code & test in pieces
     ▸ Confidence nothing is broken
     ▸ Aids in better design
     ▸ Taking small steps
     ▸ Ensures frequent save points
     

     View Slide

129. TIME FOR A STORY
     WARNING: MATH AHEAD
     

     View Slide

130. View Slide

131. TESTS SHOULD TELL A STORY
     LMS
     ▸ Per School Year
     ▸ ~ 3 Million Students
     ▸ ~ 2 Million Live Help Sessions
     ▸ ~ 1 Billion Math Problems
     ▸ Math Content Quantity Comparable to Khan Academy
     ▸ A gigantic Rails monolith + two SPA’s
     

     View Slide

132. View Slide

133. TESTS SHOULD TELL A STORY
     LIVE HELP
     ▸ Teachers available to help students
     ▸ Voice
     ▸ Text
     ▸ Whiteboard
     

     View Slide

134. View Slide

135. View Slide

136. TESTS SHOULD TELL A STORY
     LIVE HELP
     ▸ Originally in Flash
     ▸ Reimagined & Rewritten in 2013
     ▸ Goals of rewrite
     ▸ Decrease wait time of over 2 minutes
     ▸ Work on iPad
     ▸ Improve performance and maintainability
     ▸ Better pairing of teachers to students
     

     View Slide

137. TESTS SHOULD TELL A STORY
     LIVE HELP
     ▸ Rewrote in CoffeeScript with Node & Angular
     ▸ Great Success
     ▸ Throughput bumped to the current level
     ▸ Wait times decreased to typically < 15 seconds
     ▸ Compatible with iPad
     ▸ Improved pairing students to teachers
     

     View Slide

138. TESTS SHOULD TELL A STORY
     LIVE HELP
     ▸ Left largely untouched until big update in late 2015
     ▸ Compiled all CoffeeScript to JS, switched to ES2015
     ▸ Simplified server-side to boost performance + scaling
     

     View Slide

139. THE PAIRING ALGORITHM
     

     View Slide

140. View Slide

141. TESTS SHOULD TELL A STORY
     LIVE HELP PAIRING ALGORITHM
     ▸ Time-based weighting queue
     ▸ Grows linearly over time
     ▸ Those who are waiting longer get selected first
     ▸ Bonus weighting for teachers/students speaking same language
     ▸ Adds large offset that tapers over time
     ▸ Offset becomes 0 at threshold
     ▸ Fastpass match weight - Guaranteed win
     

     View Slide

142. TESTS SHOULD TELL A STORY
     GRAPHS!
     Weight Points
     0
     5000
     10000
     15000
     20000
     Seconds
     0 5 10 15 20
     Student w/ Language Mismatch
     Student w/ Language Match
     

     View Slide

143. TESTS SHOULD TELL A STORY
     LIVE HELP PAIRING ALGORITHM - WITHIN THRESHOLD
     Given a language boost threshold of 15000

     And EnglishStudent1 has waited 11s

     And SpanishStudent1 has waited 6s (13.5s)

     When a Spanish Teacher pulls in another student

     Then that student will be SpanishStudent1
     Weight
     Points
     0
     15000
     30000
     Seconds
     0 5 10 15 20 25 30
     English Student Spanish Student
     

     View Slide

144. TESTS SHOULD TELL A STORY
     LIVE HELP PAIRING ALGORITHM - WITHIN THRESHOLD
     Given a language boost threshold of 15000

     And EnglishStudent1 has waited 11s

     And SpanishStudent1 has waited 6s (13.5s)

     When a Spanish Teacher pulls in another student

     Then that student will be SpanishStudent1
     Weight
     Points
     0
     15000
     30000
     Seconds
     0 5 10 15 20 25 30
     English Student Spanish Student
     

     View Slide

145. TESTS SHOULD TELL A STORY
     LIVE HELP PAIRING ALGORITHM - PAST THRESHOLD
     Given a language boost threshold of 15000

     And EnglishStudent1 has waited 20s

     And SpanishStudent1 has waited 15s (15s)

     When a Spanish Teacher pulls in another student

     Then that student will be EnglishStudent1
     Weight
     Points
     0
     15000
     30000
     Seconds
     0 5 10 15 20 25 30
     English Student Spanish Student
     

     View Slide

146. REFACTORING SPECS
     

     View Slide

147. TESTS SHOULD TELL A STORY
     PREVIOUS SPEC (COMPILED FROM COFFEESCRIPT)
     describe("PairMatcher", function() {
     describe("Pair scoring order", function() {
     describe("Spanish speaking teachers", function() {
     beforeEach(function() {
     this.students = [
     this.helper.createSpanishStudent(), this.helper.createEnglishStudent(),
     this.helper.createSpanishStudent(), this.helper.createStudent()
     ];
     this.matcher = new PairMatcher(this.students);
     });
     it("will prefer new Spanish speaking students", function() {
     var match1, match2;
     this.offsetStudentTimes();
     match1 = this.matcher.getNextStudentFor(this.spanishTeacher);
     this.removeStudent(match1);
     match2 = this.matcher.getNextStudentFor(this.spanishTeacher);
     expect(match1.getLanguage()).toBe('es');
     expect(match2.getLanguage()).toBe('es');
     });
     });
     });
     });
     

     View Slide

148. TESTS SHOULD TELL A STORY
     EXISTING SPEC
     describe(“PairMatcher Pair scoring order for Spanish speaking teachers", function() {
     beforeEach(function() {
     this.students = [
     this.helper.createSpanishStudent(),
     this.helper.createEnglishStudent(),
     this.helper.createSpanishStudent(),
     this.helper.createStudent()
     ];
     this.matcher = new PairMatcher(this.students);
     });
     it("will prefer new Spanish speaking students", function() {
     this.offsetStudentTimes();
     var match1 = this.matcher.getNextStudentFor(this.spanishTeacher);
     this.removeStudent(match1);
     var match2 = this.matcher.getNextStudentFor(this.spanishTeacher);
     expect(match1.getLanguage()).toBe(‘es’);
     expect(match2.getLanguage()).toBe('es');
     });
     });
     

     View Slide

149. TESTS SHOULD TELL A STORY
     EXISTING SPEC
     describe(“PairMatcher Pair scoring order for Spanish speaking teachers", function() {
     beforeEach(function() {
     this.students = [
     this.helper.createSpanishStudent(),
     this.helper.createEnglishStudent(),
     this.helper.createSpanishStudent(),
     this.helper.createStudent()
     ];
     this.matcher = new PairMatcher(this.students);
     });
     it("will prefer new Spanish speaking students", function() {
     this.offsetStudentTimes();
     var match1 = this.matcher.getNextStudentFor(this.spanishTeacher);
     this.removeStudent(match1);
     var match2 = this.matcher.getNextStudentFor(this.spanishTeacher);
     expect(match1.getLanguage()).toBe(‘es’);
     expect(match2.getLanguage()).toBe('es');
     });
     });
     

     View Slide

150. TESTS SHOULD TELL A STORY
     EXISTING SPEC
     describe(“PairMatcher Pair scoring order for Spanish speaking teachers", function() {
     beforeEach(function() {
     this.students = [
     this.helper.createSpanishStudent(),
     this.helper.createEnglishStudent(),
     this.helper.createSpanishStudent(),
     this.helper.createStudent()
     ];
     this.matcher = new PairMatcher(this.students);
     });
     it("will prefer new Spanish speaking students", function() {
     this.offsetStudentTimes();
     var match1 = this.matcher.getNextStudentFor(this.spanishTeacher);
     this.removeStudent(match1);
     var match2 = this.matcher.getNextStudentFor(this.spanishTeacher);
     expect(match1.getLanguage()).toBe(‘es’);
     expect(match2.getLanguage()).toBe('es');
     });
     });
     

     View Slide

151. TESTS SHOULD TELL A STORY
     EXISTING SPEC
     describe(“PairMatcher Pair scoring order for Spanish speaking teachers", function() {
     beforeEach(function() {
     this.students = [
     this.helper.createSpanishStudent(),
     this.helper.createEnglishStudent(),
     this.helper.createSpanishStudent(),
     this.helper.createStudent()
     ];
     this.matcher = new PairMatcher(this.students);
     });
     it("will prefer new Spanish speaking students", function() {
     this.offsetStudentTimes();
     var match1 = this.matcher.getNextStudentFor(this.spanishTeacher);
     this.removeStudent(match1);
     var match2 = this.matcher.getNextStudentFor(this.spanishTeacher);
     expect(match1.getLanguage()).toBe(‘es’);
     expect(match2.getLanguage()).toBe('es');
     });
     });
     WHAT LANGUAGE DOES
     STUDENT SPEAK?
     

     View Slide

152. TESTS SHOULD TELL A STORY
     EXISTING SPEC
     describe(“PairMatcher Pair scoring order for Spanish speaking teachers", function() {
     beforeEach(function() {
     this.students = [
     this.helper.createSpanishStudent(),
     this.helper.createEnglishStudent(),
     this.helper.createSpanishStudent(),
     this.helper.createStudent()
     ];
     this.matcher = new PairMatcher(this.students);
     });
     it("will prefer new Spanish speaking students", function() {
     this.offsetStudentTimes();
     var match1 = this.matcher.getNextStudentFor(this.spanishTeacher);
     this.removeStudent(match1);
     var match2 = this.matcher.getNextStudentFor(this.spanishTeacher);
     expect(match1.getLanguage()).toBe(‘es’);
     expect(match2.getLanguage()).toBe('es');
     });
     });
     

     View Slide

153. TESTS SHOULD TELL A STORY
     EXISTING SPEC
     describe(“PairMatcher Pair scoring order for Spanish speaking teachers", function() {
     beforeEach(function() {
     this.students = [
     this.helper.createSpanishStudent(),
     this.helper.createEnglishStudent(),
     this.helper.createSpanishStudent(),
     this.helper.createStudent()
     ];
     this.matcher = new PairMatcher(this.students);
     });
     it("will prefer new Spanish speaking students", function() {
     this.offsetStudentTimes();
     var match1 = this.matcher.getNextStudentFor(this.spanishTeacher);
     this.removeStudent(match1);
     var match2 = this.matcher.getNextStudentFor(this.spanishTeacher);
     expect(match1.getLanguage()).toBe(‘es’);
     expect(match2.getLanguage()).toBe('es');
     });
     });
     

     View Slide

154. TESTS SHOULD TELL A STORY
     EXISTING SPEC
     describe(“PairMatcher Pair scoring order for Spanish speaking teachers", function() {
     beforeEach(function() {
     this.students = [
     this.helper.createSpanishStudent(),
     this.helper.createEnglishStudent(),
     this.helper.createSpanishStudent(),
     this.helper.createStudent()
     ];
     this.matcher = new PairMatcher(this.students);
     });
     it("will prefer new Spanish speaking students", function() {
     this.offsetStudentTimes();
     var match1 = this.matcher.getNextStudentFor(this.spanishTeacher);
     this.removeStudent(match1);
     var match2 = this.matcher.getNextStudentFor(this.spanishTeacher);
     expect(match1.getLanguage()).toBe(‘es’);
     expect(match2.getLanguage()).toBe('es');
     });
     });
     WTF IS THIS?
     

     View Slide

155. TESTS SHOULD TELL A STORY
     EXISTING SPEC
     describe(“PairMatcher Pair scoring order for Spanish speaking teachers", function() {
     beforeEach(function() {
     this.students = [
     this.helper.createSpanishStudent(),
     this.helper.createEnglishStudent(),
     this.helper.createSpanishStudent(),
     this.helper.createStudent()
     ];
     this.matcher = new PairMatcher(this.students);
     });
     it("will prefer new Spanish speaking students", function() {
     this.offsetStudentTimes();
     var match1 = this.matcher.getNextStudentFor(this.spanishTeacher);
     this.removeStudent(match1);
     var match2 = this.matcher.getNextStudentFor(this.spanishTeacher);
     expect(match1.getLanguage()).toBe(‘es’);
     expect(match2.getLanguage()).toBe('es');
     });
     });
     WTF IS THIS?
     ADD OPTIONAL OFFSET

     STAGGER WAIT TIMES

     REVERSE CHRONOLOGICALLY
     

     View Slide

156. TESTS SHOULD TELL A STORY
     EXISTING SPEC
     describe(“PairMatcher Pair scoring order for Spanish speaking teachers", function() {
     beforeEach(function() {
     this.students = [
     this.helper.createSpanishStudent(),
     this.helper.createEnglishStudent(),
     this.helper.createSpanishStudent(),
     this.helper.createStudent()
     ];
     this.matcher = new PairMatcher(this.students);
     });
     it("will prefer new Spanish speaking students", function() {
     this.offsetStudentTimes();
     var match1 = this.matcher.getNextStudentFor(this.spanishTeacher);
     this.removeStudent(match1);
     var match2 = this.matcher.getNextStudentFor(this.spanishTeacher);
     expect(match1.getLanguage()).toBe(‘es’);
     expect(match2.getLanguage()).toBe('es');
     });
     });
     

     View Slide

157. TESTS SHOULD TELL A STORY
     EXISTING SPEC
     describe(“PairMatcher Pair scoring order for Spanish speaking teachers", function() {
     beforeEach(function() {
     this.students = [
     this.helper.createSpanishStudent(),
     this.helper.createEnglishStudent(),
     this.helper.createSpanishStudent(),
     this.helper.createStudent()
     ];
     this.matcher = new PairMatcher(this.students);
     });
     it("will prefer new Spanish speaking students", function() {
     this.offsetStudentTimes();
     var match1 = this.matcher.getNextStudentFor(this.spanishTeacher);
     this.removeStudent(match1);
     var match2 = this.matcher.getNextStudentFor(this.spanishTeacher);
     expect(match1.getLanguage()).toBe(‘es’);
     expect(match2.getLanguage()).toBe('es');
     });
     });
     WUT?
     

     View Slide

158. TESTS SHOULD TELL A STORY
     EXISTING SPEC
     describe(“PairMatcher Pair scoring order for Spanish speaking teachers", function() {
     beforeEach(function() {
     this.students = [
     this.helper.createSpanishStudent(),
     this.helper.createEnglishStudent(),
     this.helper.createSpanishStudent(),
     this.helper.createStudent()
     ];
     this.matcher = new PairMatcher(this.students);
     });
     it("will prefer new Spanish speaking students", function() {
     this.offsetStudentTimes();
     var match1 = this.matcher.getNextStudentFor(this.spanishTeacher);
     this.removeStudent(match1);
     var match2 = this.matcher.getNextStudentFor(this.spanishTeacher);
     expect(match1.getLanguage()).toBe(‘es’);
     expect(match2.getLanguage()).toBe('es');
     });
     });
     

     View Slide

159. TESTS SHOULD TELL A STORY
     THE OLD STORY
     Describe the pair order for Spanish speaking teachers
     Given this list of four students [es, en, es, en]

     And all have wait times within the language threshold

     And each is waiting longer than the previous

     When the teacher pulls two new students

     Then the teacher should receive the Spanish speaking students
     

     View Slide

160. TESTS SHOULD TELL A STORY
     THE OLD STORY
     describe(“PairMatcher Pair scoring order for Spanish speaking teachers", function() {
     beforeEach(function() {
     this.students = [
     this.helper.createSpanishStudent(),
     this.helper.createEnglishStudent(),
     this.helper.createSpanishStudent(),
     this.helper.createStudent()
     ];
     this.matcher = new PairMatcher(this.students);
     });
     it("will prefer new Spanish speaking students", function() {
     this.offsetStudentTimes();
     var match1 = this.matcher.getNextStudentFor(this.spanishTeacher);
     this.removeStudent(match1);
     var match2 = this.matcher.getNextStudentFor(this.spanishTeacher);
     expect(match1.getLanguage()).toBe(‘es’);
     expect(match2.getLanguage()).toBe('es');
     });
     });
     THE PROLOGUE
     

     View Slide

161. TESTS SHOULD TELL A STORY
     THE OLD STORY
     describe(“PairMatcher Pair scoring order for Spanish speaking teachers", function() {
     beforeEach(function() {
     this.students = [
     this.helper.createSpanishStudent(),
     this.helper.createEnglishStudent(),
     this.helper.createSpanishStudent(),
     this.helper.createStudent()
     ];
     this.matcher = new PairMatcher(this.students);
     });
     it("will prefer new Spanish speaking students", function() {
     this.offsetStudentTimes();
     var match1 = this.matcher.getNextStudentFor(this.spanishTeacher);
     this.removeStudent(match1);
     var match2 = this.matcher.getNextStudentFor(this.spanishTeacher);
     expect(match1.getLanguage()).toBe(‘es’);
     expect(match2.getLanguage()).toBe('es');
     });
     });
     THE SUPPORTING CAST
     

     View Slide

162. TESTS SHOULD TELL A STORY
     THE OLD STORY
     describe(“PairMatcher Pair scoring order for Spanish speaking teachers", function() {
     beforeEach(function() {
     this.students = [
     this.helper.createSpanishStudent(),
     this.helper.createEnglishStudent(),
     this.helper.createSpanishStudent(),
     this.helper.createStudent()
     ];
     this.matcher = new PairMatcher(this.students);
     });
     it("will prefer new Spanish speaking students", function() {
     this.offsetStudentTimes();
     var match1 = this.matcher.getNextStudentFor(this.spanishTeacher);
     this.removeStudent(match1);
     var match2 = this.matcher.getNextStudentFor(this.spanishTeacher);
     expect(match1.getLanguage()).toBe(‘es’);
     expect(match2.getLanguage()).toBe('es');
     });
     });
     THE PROTAGONIST
     

     View Slide

163. TESTS SHOULD TELL A STORY
     THE OLD STORY
     describe(“PairMatcher Pair scoring order for Spanish speaking teachers", function() {
     beforeEach(function() {
     this.students = [
     this.helper.createSpanishStudent(),
     this.helper.createEnglishStudent(),
     this.helper.createSpanishStudent(),
     this.helper.createStudent()
     ];
     this.matcher = new PairMatcher(this.students);
     });
     it("will prefer new Spanish speaking students", function() {
     this.offsetStudentTimes();
     var match1 = this.matcher.getNextStudentFor(this.spanishTeacher);
     this.removeStudent(match1);
     var match2 = this.matcher.getNextStudentFor(this.spanishTeacher);
     expect(match1.getLanguage()).toBe(‘es’);
     expect(match2.getLanguage()).toBe('es');
     });
     });
     THE PLOT
     

     View Slide

164. TESTS SHOULD TELL A STORY
     THE OLD STORY
     describe(“PairMatcher Pair scoring order for Spanish speaking teachers", function() {
     beforeEach(function() {
     this.students = [
     this.helper.createSpanishStudent(),
     this.helper.createEnglishStudent(),
     this.helper.createSpanishStudent(),
     this.helper.createStudent()
     ];
     this.matcher = new PairMatcher(this.students);
     });
     it("will prefer new Spanish speaking students", function() {
     this.offsetStudentTimes();
     var match1 = this.matcher.getNextStudentFor(this.spanishTeacher);
     this.removeStudent(match1);
     var match2 = this.matcher.getNextStudentFor(this.spanishTeacher);
     expect(match1.getLanguage()).toBe(‘es’);
     expect(match2.getLanguage()).toBe('es');
     });
     });
     M. NIGHT SHYMALAN TWIST &

     NO CHARACTER DEVELOPMENT
     

     View Slide

165. TESTS SHOULD TELL A STORY
     THE OLD STORY
     describe(“PairMatcher Pair scoring order for Spanish speaking teachers", function() {
     beforeEach(function() {
     this.students = [
     this.helper.createSpanishStudent(),
     this.helper.createEnglishStudent(),
     this.helper.createSpanishStudent(),
     this.helper.createStudent()
     ];
     this.matcher = new PairMatcher(this.students);
     });
     it("will prefer new Spanish speaking students", function() {
     this.offsetStudentTimes();
     var match1 = this.matcher.getNextStudentFor(this.spanishTeacher);
     this.removeStudent(match1);
     var match2 = this.matcher.getNextStudentFor(this.spanishTeacher);
     expect(match1.getLanguage()).toBe(‘es’);
     expect(match2.getLanguage()).toBe('es');
     });
     });
     THE CONFLICT
     

     View Slide

166. TESTS SHOULD TELL A STORY
     THE OLD STORY
     describe(“PairMatcher Pair scoring order for Spanish speaking teachers", function() {
     beforeEach(function() {
     this.students = [
     this.helper.createSpanishStudent(),
     this.helper.createEnglishStudent(),
     this.helper.createSpanishStudent(),
     this.helper.createStudent()
     ];
     this.matcher = new PairMatcher(this.students);
     });
     it("will prefer new Spanish speaking students", function() {
     this.offsetStudentTimes();
     var match1 = this.matcher.getNextStudentFor(this.spanishTeacher);
     this.removeStudent(match1);
     var match2 = this.matcher.getNextStudentFor(this.spanishTeacher);
     expect(match1.getLanguage()).toBe(‘es’);
     expect(match2.getLanguage()).toBe('es');
     });
     });
     PLOT HOLE
     

     View Slide

167. TESTS SHOULD TELL A STORY
     THE OLD STORY
     describe(“PairMatcher Pair scoring order for Spanish speaking teachers", function() {
     beforeEach(function() {
     this.students = [
     this.helper.createSpanishStudent(),
     this.helper.createEnglishStudent(),
     this.helper.createSpanishStudent(),
     this.helper.createStudent()
     ];
     this.matcher = new PairMatcher(this.students);
     });
     it("will prefer new Spanish speaking students", function() {
     this.offsetStudentTimes();
     var match1 = this.matcher.getNextStudentFor(this.spanishTeacher);
     this.removeStudent(match1);
     var match2 = this.matcher.getNextStudentFor(this.spanishTeacher);
     expect(match1.getLanguage()).toBe(‘es’);
     expect(match2.getLanguage()).toBe('es');
     });
     });
     BREAKING DOWN THE 4TH WALL
     

     View Slide

168. TESTS SHOULD TELL A STORY
     THE OLD STORY
     describe(“PairMatcher Pair scoring order for Spanish speaking teachers", function() {
     beforeEach(function() {
     this.students = [
     this.helper.createSpanishStudent(),
     this.helper.createEnglishStudent(),
     this.helper.createSpanishStudent(),
     this.helper.createStudent()
     ];
     this.matcher = new PairMatcher(this.students);
     });
     it("will prefer new Spanish speaking students", function() {
     this.offsetStudentTimes();
     var match1 = this.matcher.getNextStudentFor(this.spanishTeacher);
     this.removeStudent(match1);
     var match2 = this.matcher.getNextStudentFor(this.spanishTeacher);
     expect(match1.getLanguage()).toBe(‘es’);
     expect(match2.getLanguage()).toBe('es');
     });
     });
     THE RESOLUTION
     

     View Slide

169. TESTS SHOULD TELL A STORY
     GOOD THINGS ABOUT THIS SPEC
     

     View Slide

170. TESTS SHOULD TELL A STORY
     GOOD THINGS ABOUT THIS SPEC
     ▸ Mostly clear name for example group and test description
     

     View Slide

171. TESTS SHOULD TELL A STORY
     GOOD THINGS ABOUT THIS SPEC
     ▸ Mostly clear name for example group and test description
     ▸ Using this (disposable context in Jasmine)
     

     View Slide

172. TESTS SHOULD TELL A STORY
     GOOD THINGS ABOUT THIS SPEC
     ▸ Mostly clear name for example group and test description
     ▸ Using this (disposable context in Jasmine)
     ▸ Assertions match description
     

     View Slide

173. TESTS SHOULD TELL A STORY
     NOT-SO-GOOD THINGS ABOUT THIS SPEC
     

     View Slide

174. TESTS SHOULD TELL A STORY
     NOT-SO-GOOD THINGS ABOUT THIS SPEC
     ▸ Helpers cause side-effects (offsetTimes, removeStudent)
     

     View Slide

175. TESTS SHOULD TELL A STORY
     NOT-SO-GOOD THINGS ABOUT THIS SPEC
     ▸ Helpers cause side-effects (offsetTimes, removeStudent)
     ▸ Object under test has dependency mutated after use
     

     View Slide

176. TESTS SHOULD TELL A STORY
     NOT-SO-GOOD THINGS ABOUT THIS SPEC
     ▸ Helpers cause side-effects (offsetTimes, removeStudent)
     ▸ Object under test has dependency mutated after use
     ▸ Character development happens off-screen
     

     View Slide

177. TESTS SHOULD TELL A STORY
     NOT-SO-GOOD THINGS ABOUT THIS SPEC
     ▸ Helpers cause side-effects (offsetTimes, removeStudent)
     ▸ Object under test has dependency mutated after use
     ▸ Character development happens off-screen
     ▸ Expectations are dependent on result of side-effects
     

     View Slide

178. TESTS SHOULD TELL A STORY
     NOT-SO-GOOD THINGS ABOUT THIS SPEC
     ▸ Helpers cause side-effects (offsetTimes, removeStudent)
     ▸ Object under test has dependency mutated after use
     ▸ Character development happens off-screen
     ▸ Expectations are dependent on result of side-effects
     ▸ Three methods of creating a student are used
     

     View Slide

179. TESTS PASS
     SPANISH STUDENTS ARE PULLED FIRST
     

     View Slide

180. TESTS SHOULD TELL A STORY
     THE NEW STORY
     Describe A Spanish Speaking teacher pulling students with
     the same language
     Given all wait times are within the threshold

     And englishStudent1 has been waiting 3s

     And spanishStudent2 has been waiting 2s

     And spanishStudent1 has been waiting 1s

     When the teacher pulls the next student

     Then the teacher should receive spanishStudent2
     

     View Slide

181. TESTS SHOULD TELL A STORY
     THE NEW STORY
     describe('StudentTeacherScorer', function() {
     var sessions = [];
     //…
     describe('A teacher speaking same language as a student', function() {
     beforeEach(function() {
     spanishStudent1.waitTime = 1000;
     spanishStudent2.waitTime = 2000;
     englishStudent1.waitTime = 3000;
     sessions.push(englishStudent1);
     sessions.push(spanishStudent2);
     sessions.push(spanishStudent1);
     });
     it('will pick the student waiting longest', function() {
     const chosenStudent = scorer.findBestMatchFor(sessions, spanishTeacher);
     expect(chosenStudent).toEqual(spanishStudent2);
     });
     });
     });
     

     View Slide

182. TESTS SHOULD TELL A STORY
     THE NEW STORY
     describe('StudentTeacherScorer', function() {
     var sessions = [];
     //…
     describe('A teacher speaking same language as a student', function() {
     beforeEach(function() {
     spanishStudent1.waitTime = 1000;
     spanishStudent2.waitTime = 2000;
     englishStudent1.waitTime = 3000;
     sessions.push(englishStudent1);
     sessions.push(spanishStudent2);
     sessions.push(spanishStudent1);
     });
     it('will pick the student waiting longest', function() {
     const chosenStudent = scorer.findBestMatchFor(sessions, spanishTeacher);
     expect(chosenStudent).toEqual(spanishStudent2);
     });
     });
     });
     THE PROLOGUE
     

     View Slide

183. TESTS SHOULD TELL A STORY
     THE NEW STORY
     describe('StudentTeacherScorer', function() {
     var sessions = [];
     //…
     describe('A teacher speaking same language as a student', function() {
     beforeEach(function() {
     spanishStudent1.waitTime = 1000;
     spanishStudent2.waitTime = 2000;
     englishStudent1.waitTime = 3000;
     sessions.push(englishStudent1);
     sessions.push(spanishStudent2);
     sessions.push(spanishStudent1);
     });
     it('will pick the student waiting longest', function() {
     const chosenStudent = scorer.findBestMatchFor(sessions, spanishTeacher);
     expect(chosenStudent).toEqual(spanishStudent2);
     });
     });
     });
     CHARACTER DEVELOPMENT
     

     View Slide

184. TESTS SHOULD TELL A STORY
     THE NEW STORY
     describe('StudentTeacherScorer', function() {
     var sessions = [];
     //…
     describe('A teacher speaking same language as a student', function() {
     beforeEach(function() {
     spanishStudent1.waitTime = 1000;
     spanishStudent2.waitTime = 2000;
     englishStudent1.waitTime = 3000;
     sessions.push(englishStudent1);
     sessions.push(spanishStudent2);
     sessions.push(spanishStudent1);
     });
     it('will pick the student waiting longest', function() {
     const chosenStudent = scorer.findBestMatchFor(sessions, spanishTeacher);
     expect(chosenStudent).toEqual(spanishStudent2);
     });
     });
     });
     THE CHOSEN ONE
     

     View Slide

185. TESTS SHOULD TELL A STORY
     THE NEW STORY
     describe('StudentTeacherScorer', function() {
     var sessions = [];
     //…
     describe('A teacher speaking same language as a student', function() {
     beforeEach(function() {
     spanishStudent1.waitTime = 1000;
     spanishStudent2.waitTime = 2000;
     englishStudent1.waitTime = 3000;
     sessions.push(englishStudent1);
     sessions.push(spanishStudent2);
     sessions.push(spanishStudent1);
     });
     it('will pick the student waiting longest', function() {
     const chosenStudent = scorer.findBestMatchFor(sessions, spanishTeacher);
     expect(chosenStudent).toEqual(spanishStudent2);
     });
     });
     });
     THE PLOT
     

     View Slide

186. TESTS SHOULD TELL A STORY
     THE NEW STORY
     describe('StudentTeacherScorer', function() {
     var sessions = [];
     //…
     describe('A teacher speaking same language as a student', function() {
     beforeEach(function() {
     spanishStudent1.waitTime = 1000;
     spanishStudent2.waitTime = 2000;
     englishStudent1.waitTime = 3000;
     sessions.push(englishStudent1);
     sessions.push(spanishStudent2);
     sessions.push(spanishStudent1);
     });
     it('will pick the student waiting longest', function() {
     const chosenStudent = scorer.findBestMatchFor(sessions, spanishTeacher);
     expect(chosenStudent).toEqual(spanishStudent2);
     });
     });
     });
     THE CONFLICT
     

     View Slide

187. TESTS SHOULD TELL A STORY
     THE NEW STORY
     describe('StudentTeacherScorer', function() {
     var sessions = [];
     //…
     describe('A teacher speaking same language as a student', function() {
     beforeEach(function() {
     spanishStudent1.waitTime = 1000;
     spanishStudent2.waitTime = 2000;
     englishStudent1.waitTime = 3000;
     sessions.push(englishStudent1);
     sessions.push(spanishStudent2);
     sessions.push(spanishStudent1);
     });
     it('will pick the student waiting longest', function() {
     const chosenStudent = scorer.findBestMatchFor(sessions, spanishTeacher);
     expect(chosenStudent).toEqual(spanishStudent2);
     });
     });
     });
     THE RESOLUTION
     

     View Slide

188. TESTS FAIL
     

     View Slide

189. TESTS FAIL
     Expected: spanishStudent2
     Actual: spanishStudent1
     

     View Slide

190. View Slide

191. spanishStudent1.waitTime = 1000;
     spanishStudent2.waitTime = 2000;
     

     View Slide

192. 1000 > 2000?
     spanishStudent1.waitTime = 1000;
     spanishStudent2.waitTime = 2000;
     

     View Slide

193. 1000 > 2000?
     spanishStudent1.waitTime = 1000;
     spanishStudent2.waitTime = 2000;
     

     View Slide

194. EXISTING BEHAVIOR
     VERIFIED BY RUNNING THE OLD SPEC
     WITH NEW ASSERTIONS
     

     View Slide

195. A WILD BUG APPEARS
     MATH TO THE RESCUE!
     

     View Slide

196. TESTS SHOULD TELL A STORY
     I AM AWFUL AT SPREADSHEETS
     Score w/ Language
     Language Weight
     Normal Score
     X-axis: Time
     Y-axis: Score
     

     View Slide

197. TESTS SHOULD TELL A STORY
     I AM AWFUL AT SPREADSHEETS
     Lang score
     decreased
     over time till
     negated
     Score w/ Language
     Language Weight
     Normal Score
     X-axis: Time
     Y-axis: Score
     

     View Slide

198. TESTS SHOULD TELL A STORY
     I AM AWFUL AT SPREADSHEETS
     Score should
     always
     increase
     Lang score
     decreased
     over time till
     negated
     Score w/ Language
     Language Weight
     Normal Score
     X-axis: Time
     Y-axis: Score
     

     View Slide

199. WHAT DID WE DO ABOUT IT?
     

     View Slide

200. TESTS SHOULD TELL A STORY
     HACK THE PLANET
     it('will pick the student waiting longest', function() {
     const chosenStudent = scorer.findBestMatchFor(sessions, spanishTeacher);
     expect(chosenStudent).toEqual(spanishStudent2);
     });
     

     View Slide

201. TESTS SHOULD TELL A STORY
     HACK THE PLANET
     it('will pick the student waiting shortestlongest', function() {
     const chosenStudent = scorer.findBestMatchFor(sessions, spanishTeacher);
     expect(chosenStudent).toEqual(spanishStudent2);
     });
     

     View Slide

202. TESTS SHOULD TELL A STORY
     HACK THE PLANET
     it('will pick the student waiting shortestlongest', function() {
     const chosenStudent = scorer.findBestMatchFor(sessions, spanishTeacher);
     expect(chosenStudent).toEqual(spanishStudent2);
     });
     // TODO: This behavior is probably unintended, but the algorithm has not been changed.
     // It appears as though students who have waited *less* than the ELL threshold are actually
     // processed in the opposite order than we intend. Once they get beyond the ELL threshold
     // then wait time correctly influences the student scoring.
     

     View Slide

203. TALK TO STAKEHOLDERS
     

     View Slide

204. THEY SAID TO PUNT ON IT
     FIX EVENTUALLY
     BUT BEEN LIVING WITH IT FOR YEARS
     

     View Slide

205. View Slide

206. WE ARE A
     PITTSBURGH
     COMPANY
     

     View Slide

207. SO ON THE PUNT RETURN…
     

     View Slide

208. View Slide

209. FOUND THE BUG!
     

     View Slide

210. PAST-SELF FUDGED SOME
     MATH
     I WORK FOR A MATH COMPANY
     i·ro·ny
     /ˈīrənē/ noun
     

     View Slide

211. FIXED THE CALCULATION
     REVERTED THE SPEC
     

     View Slide

212. TESTS PASS
     

     View Slide

213. HOWEVER…
     AN ACCEPTANCE TEST BROKE ELSEWHERE
     UNRELATED TO LANGUAGE
     

     View Slide

214. CURSE JAVASCRIPT
     

     View Slide

215. View Slide

216. View Slide

217. TESTS SHOULD TELL A STORY
     IN THIS ACCEPTANCE TEST
     

     View Slide

218. TESTS SHOULD TELL A STORY
     IN THIS ACCEPTANCE TEST
     ▸ Had an English Speaking teacher accepting fast pass
     

     View Slide

219. TESTS SHOULD TELL A STORY
     IN THIS ACCEPTANCE TEST
     ▸ Had an English Speaking teacher accepting fast pass
     ▸ Enqueued a English speaking student
     

     View Slide

220. TESTS SHOULD TELL A STORY
     IN THIS ACCEPTANCE TEST
     ▸ Had an English Speaking teacher accepting fast pass
     ▸ Enqueued a English speaking student
     ▸ Waited a while
     

     View Slide

221. TESTS SHOULD TELL A STORY
     IN THIS ACCEPTANCE TEST
     ▸ Had an English Speaking teacher accepting fast pass
     ▸ Enqueued a English speaking student
     ▸ Waited a while
     ▸ Enqueued another English speaking student w/ fast pass
     

     View Slide

222. TESTS SHOULD TELL A STORY
     IN THIS ACCEPTANCE TEST
     ▸ Had an English Speaking teacher accepting fast pass
     ▸ Enqueued a English speaking student
     ▸ Waited a while
     ▸ Enqueued another English speaking student w/ fast pass
     ▸ Fast pass ensures second student gets max score, no way
     to lose
     

     View Slide

223. WE LOST
     

     View Slide

224. TEST FIXTURE WASN’T BEING
     SET CORRECTLY
     

     View Slide

225. PATCHED, STILL FAILED
     MEANING THIS WAS A PRODUCTION BUG
     

     View Slide

226. PATCHED CODE
     DESERIALIZATION AND CONSTRUCTION
     DIFFERED
     

     View Slide

227. TESTS PASS
     

     View Slide

228. TESTS SHOULD TELL A STORY
     WHAT HAPPENED?
     

     View Slide

229. TESTS SHOULD TELL A STORY
     WHAT HAPPENED?
     ▸ Earlier bug hid this
     ▸ Forced shorter times to be favored on language match
     ▸ Was documented as working the other way
     

     View Slide

230. TESTS SHOULD TELL A STORY
     WHAT HAPPENED?
     ▸ Earlier bug hid this
     ▸ Forced shorter times to be favored on language match
     ▸ Was documented as working the other way
     ▸ Our acceptance test worked because of order dependency
     ▸ Only two students, last student was under test and won
     favorability
     ▸ Putting another student closer could have prevented failure
     

     View Slide

231. MORALS OF THE STORY
     

     View Slide

232. TESTS SHOULD TELL A STORY
     MORALS OF THE STORY
     

     View Slide

233. TESTS SHOULD TELL A STORY
     MORALS OF THE STORY
     ▸ Favor explicit assertions over potential coincidence
     

     View Slide

234. TESTS SHOULD TELL A STORY
     MORALS OF THE STORY
     ▸ Favor explicit assertions over potential coincidence
     ▸ Favor specs that tell the story you need to know
     

     View Slide

235. TESTS SHOULD TELL A STORY
     MORALS OF THE STORY
     ▸ Favor explicit assertions over potential coincidence
     ▸ Favor specs that tell the story you need to know
     ▸ Beware of coincidental truths
     

     View Slide

236. TESTS SHOULD TELL A STORY
     MORALS OF THE STORY
     ▸ Favor explicit assertions over potential coincidence
     ▸ Favor specs that tell the story you need to know
     ▸ Beware of coincidental truths
     ▸ Don’t be overly clever with fixtures/fake data
     

     View Slide

237. TESTS SHOULD TELL A STORY
     MORALS OF THE STORY
     ▸ Favor explicit assertions over potential coincidence
     ▸ Favor specs that tell the story you need to know
     ▸ Beware of coincidental truths
     ▸ Don’t be overly clever with fixtures/fake data
     ▸ Our careers are founded on math - learn more math
     

     View Slide

238. QUESTIONS?
     

     View Slide

239. I’M MATT MACHUGA
     Twitter, GitHub, Freenode: machuga
     

     View Slide

240. ERIE, PA
     

     View Slide

241. ERIE, PA
     

     View Slide

242. Hiring Software Developers!
     TTM IS HIRING!
     CONSULTING & TEACHING
     Small to medium projects
     

     View Slide