The document discusses moving away from legacy code using Behavior-Driven Development (BDD) by identifying the goals and minimal viable products through techniques like impact and feature mapping. It emphasizes the importance of continuous refactoring and delivery strategies while providing options such as full rewrites, functional refactoring, or business-oriented rewrites via a BDD pipeline. Additionally, it outlines the steps to implement and automate BDD processes within development projects, including real-world applications and lessons learned.

1. Moving away from
legacy code
with BDD

2. Who?
!
BDD Evangelist
!
BDD Practice Manager @Inviqa
!
Creator of Behat, Mink, PhpSpec2,
Prophecy
!
Contributor to Symfony2, Composer
!
Host of the “Elephant in the Room”
podcast

3. This talk is about
•
Solving purely technical “TCIAM” problem with agile
business analysis and discovery processes
•
Building a delivery strategy on the idea of constant
change
•
Real-life experience

4. This talk is not about
•
Greenfield projects
•
Solutions for everyone
•
How to write code

5. This talk is not about
•
Greenfield projects
•
Maintenance-mode projects
•
Solutions for everyone
•
How to write code (well, mostly)

6. Legacy projects

7. How most developers see
their next project

8. My next
project

9. My next
project
His actual next
project

10. Agile, TDD, BDD,
General QA, etc…
// TODO: refactor this
later

11. Is it really that bad?

12. If the project can afford at least one full-time
specialist on a payroll that whines how horrible
this project is, then surely it did something right.

13. // TODO: refactor this
later

14. // TODO: refactor this
later

15. // TODO: refactor this
later

16. This world is full of brilliant projects that nobody
wants to whine about. Sadly, it’s often simply
because there’s no one left to pay for that.

17. The truth is:
You deliver value!
Just not as effectively as you could

18. Agile, TDD, BDD,
General QA, etc…
// TODO: refactor this
later

19. How?

20. Three options
1. Rewrite an entire application using “the right way”
2. Do functional refactoring
3. Do business-oriented rewrite using “BDD pipeline”

21. #1: Full Rewrite

22. #1: Full Rewrite
•
Scrum / Kanban
•
TDD / BDD / DDD / Pair-programming
•
New everything
•
Mirroring functionality

23. #1: Income

24. 6 Months later…

25. #1: Almost there…

26. #1: Full Rewrite
Just spaghetti, please: 4 man years
Full London meal (TDD, BDD, Agile, QA): ??? man years

27. #2: FUNCTIONAL
Refactoring

28. #2: Functional Refactoring
•
Blackbox testing
•
New routing
•
New templating system
•
Migration of model layer (MySQL -> Mongo)

29. #2: Income

30. 6 Months later…

31. #2: Ta-da!!!

32. “Exactly what did you do here?”
– Your client. (most likely)

33. #3: BDD PIPELINE
AKA Business-Oriented rewrite

34. Why do some legacy
projects suck?

35. Cost
Because of the
cost of change
Time

36. … Of change where?

37. Why do applications
change?

38. Welcome to the
wonderland
of Agile Business Analysis

39. Questionnaire
1. What is the goal and minimal valuable product?
2. What is the minimal set of features to support it?
3. Which features are more likely to change?
4. How fully those features should be implemented?
5. How to avoid gold plating?

40. “BDD Pipeline”
1. Impact Mapping
2. Feature Mapping
3. Prioritisation
4. Example Workshop
5. Full-stack BDD

41. 1. What is the Goal &
minimal valuable product?
Impact Mapping

42. “Impact mapping is a strategic planning technique
that prevents organisations from getting lost
while building products and delivering projects,
by clearly communicating assumptions, helping
teams align their activities with overall business
objectives and make better roadmap decisions.”
– Gojko Adzic

43. Four levels of Impact Map
1. Why? are we doing all this (rewrite)? What is the
goal we’re trying to achieve?
2. Who? will be impacted by it?
3. How? can they help us to achieve the goal?
4. What? can we do to support them?

45. MVP

46. impactmapping.org

47. 2. What is the minimal set
of features to support it?
Feature Mapping

48. “Feature mapping is a backlog grooming
technique. It is a graphical process which helps
teams in finding features that are necessary to
support discovered MVP”
– Marcello Duarte

49. Three levels of feature map
1. What? is the minimal marketable feature?
2. Who? will be impacted by this feature?
3. What? particular parts of this feature do they need
to create this impact?

51. Product Backlog

53. In order to buy more products
As a customer
I need to have a product autocompletion in the search field

54. 3. Which features are
more likely to change?
Prioritisation workshop

55. In order to maintain my shopping history
As a site visitor
I need to be able to register on this site

56. In order to maintain my shopping history
As a site visitor
I need to be able to register on this site
benefit
!
actor

57. SELECT s.*
FROM backlog as s
ORDER BY s.role, s.benefit
LIMIT 25

58. 4. How fully those features
should be implemented?
Example workshops

59. Three layers of a User-Story
•
Business rule(s)
•
Communication
•
Acceptance criteria

60. Three layers of a User-Story
•
Business rule(s) == Acceptance criteria
•
Communication

61. Three layers of a User-Story
•
Business rule(s) == Acceptance criteria
•
Communication == Examples

62. Three layers of a User-Story
•
Business rule(s)
•
Communication == Examples == Acceptance criteria

63. Feature: registration
in order to maintain my shopping history
as a site visitor
i need to be able to register on this site

64. Feature: registration
in order to maintain my shopping history
as a site visitor
i need to be able to register on this site
Scenario: Successful registration when visitor provides all the required info

65. Feature: registration
in order to maintain my shopping history
as a site visitor
i need to be able to register on this site
Scenario: Successful registration when visitor provides all the required info
Scenario: Unable to register when visitor misses required info

66. Feature: registration
in order to maintain my shopping history
as a site visitor
i need to be able to register on this site
Scenario: Successful registration when visitor provides all the required info
Scenario: Unable to register when visitor misses required info
Scenario: ...

67. Feature: registration
in order to maintain my shopping history
as a site visitor
i need to be able to register on this site
Scenario: Successful registration when visitor provides all the required info
Scenario: Unable to register when visitor misses required info
Scenario: ...
Scenario: ...
Scenario: ...
Scenario: ...
Scenario: ...

68. Feature: registration
in order to maintain my shopping history
as a site visitor
i need to be able to register on this site
Scenario: Successful registration when visitor provides all the required info
Given I am on the homepage
When I follow “sign up”
And I fill in registration form
And I submit it
Then I should be successfully registered
And I should be on the homepage again

69. 5. How to avoid
gold plating?
Delivery

70. Architecture

71. Architecture
HTTP layering

72. [GET] /products
Infrastructure
Legacy system

73. [GET] /products
[GET] /products/123
Infrastructure
Legacy system

74. [GET] /products
[GET] /products/123
New system
Infrastructure
Legacy system

75. [GET] /products
[GET] /products/123
New system
Infrastructure
Legacy system
New system

76. Implementation

77. Implementation
Full-stack BDD

78. Stories
Examples
Describe
Design
Implement

79. Stories
Examples
Describe
Scenario-BDD
Design
Implement

80. Feature: registration
in order to maintain my shopping history
as a site visitor
i need to be able to register on this site
Scenario: Successful registration when visitor provides all the required info
Given I am on the homepage
When I follow “sign up”
And I fill in registration form
And I submit it
Then I should be successfully registered
And I should be on the homepage again

81. Feature:
in order
as a
i need
Scenario: Successful registration when visitor provides
Given I am on the
When
And I fill in
And I submit it
Then
And I should be on the homepage
What could be automated
should be automated

83. assertEquals(Your Feature, Your App)

84. Setup
1. Dump your sprint features into text files
2. Put those text files into the `features/` folder inside
project
3. Install behat (via composer or behat.phar)
4. Initialize behat test suite by running `bin/behat —init`

85. Feature Context
<?php
!
use BehatBehatContextClosuredContextInterface,
BehatBehatContextTranslatedContextInterface,
BehatBehatContextBehatContext,
BehatBehatExceptionPendingException;
use BehatGherkinNodePyStringNode,
BehatGherkinNodeTableNode;
!
class FeatureContext extends BehatContext
{
}

86. First run
$> bin/behat
...
You can implement step definitions for undefined steps with these snippets:
!
/**
* @Then I should see :arg1
*/
public function iShouldSee($arg1)
{
throw new PendingException();
}
...

87. Append snippets
$> bin/behat --append-snippets

88. Feedback loop
$> bin/behat
!
Feature: registration
in order to maintain my shopping history
as a site visitor
i need to be able to register on this site
!
Scenario: Successful registration when visitor provides all the required info
Given I am on the homepage
TODO: write pending definition
When I follow “sign up”
And I fill in registration form
And I submit it
Then I should be successfully registered
And I should be on the homepage again

89. Stories
Examples
Describe
Scenario-BDD
Design
Implement

90. Colour it Red

91. Colour it red
/**
* @Given /^I am on the homepage$/
*/
public function iAmOnTheHomepage()
{
$crawler = new SomeCrawlerLibCrawler();
$crawler->goto(“http://localhost:8080/”);
if (200 !== $crawler->getCurrentStatusCode())
{
throw new RuntimeException(‘Can not open homepage’);
}
}

92. Colour it red
$> bin/behat
!
Feature: registration
in order to maintain my shopping history
as a site visitor
i need to be able to register on this site
!
Scenario: Successful registration when visitor provides all the required info
Given I am on the homepage
Can not open homepage (RuntimeException)
When I follow “sign up”
And I fill in registration form
And I submit it
Then I should be successfully registered
And I should be on the homepage again

93. Stories
Examples
Describe
Scenario-BDD
Design
Implement

94. Change the message
As quickly as possible

95. Change the message
$> bin/behat
!
Feature: registration
in order to maintain my shopping history
as a site visitor
i need to be able to register on this site
!
Scenario: Successful registration when visitor provides all the required info
Given I am on the homepage
Can not open homepage (RuntimeException)
When I follow “sign up”
And I fill in registration form
And I submit it
Then I should be successfully registered
And I should be on the homepage again

96. Change the message
$> bin/behat
!
Feature: registration
in order to maintain my shopping history
as a site visitor
i need to be able to register on this site
!
Scenario: Successful registration when visitor provides all the required info
Given I am on the homepage
Route … not found (FrameworkException)
When I follow “sign up”
And I fill in registration form
And I submit it
Then I should be successfully registered
And I should be on the homepage again

97. Change the message
$> bin/behat
!
Feature: registration
in order to maintain my shopping history
as a site visitor
i need to be able to register on this site
!
Scenario: Successful registration when visitor provides all the required info
Given I am on the homepage
Template … not found (FrameworkException)
When I follow “sign up”
And I fill in registration form
And I submit it
Then I should be successfully registered
And I should be on the homepage again

98. Change the message
$> bin/behat
!
Feature: registration
in order to maintain my shopping history
as a site visitor
i need to be able to register on this site
!
Scenario: Successful registration when visitor provides all the required info
Given I am on the homepage
When I follow “sign up”
TODO: write pending definition
And I fill in registration form
And I submit it
Then I should be successfully registered
And I should be on the homepage again

99. behat.org

100. Change the message
$> bin/behat
!
Feature: registration
in order to maintain my shopping history
as a site visitor
i need to be able to register on this site
!
Scenario: Successful registration when visitor provides all the required info
Given I am on the homepage
When I follow “sign up”
And I fill in registration form
And I submit it
Then I should be successfully registered
Object `User` and its method `isRegistered` does not exist (RuntimeException)
And I should be on the homepage again

101. Stories
Spec-BDD
Examples
Describe
Design
Implement

103. Setup
1. Install phpspec via composer
2. use it

104. Stories
Spec-BDD
Examples
Describe
Design
Implement

105. Prepare your first spec
$> bin/phpspec desc Acme/Userbase/User

106. Describe your first message
<?php
!
namespace specAcmeUserbase;
!
class User extends ObjectBehavior
{
function it_is_registered_by_default()
{
$this->shouldBeRegistered();
}
}

107. Colour it red
$> bin/phpspec
!
Class “AcmeUserbaseUser” does not exist. Create? [Y/n]
y
!
Method `AcmeUserbaseUser::isRegistered()` does not exist. Create? [Y/n]
y

108. Stories
Spec-BDD
Examples
Describe
Design
Implement

109. Stories
Spec-BDD
Examples
Describe
Design
Implement

110. Stories
Spec-BDD
Examples
Describe
Design
Implement

111. phpspec.net

112. Verify feature
$> bin/behat
!
Feature: registration
in order to maintain my shopping history
as a site visitor
i need to be able to register on this site
!
Scenario: Successful registration when visitor provides all the required info
Given I am on the homepage
When I follow “sign up”
And I fill in registration form
And I submit it
Then I should be successfully registered
And I should be on the homepage again

113. Verify feature
$> bin/behat
!
Feature: registration
in order to maintain my shopping history
as a site visitor
i need to be able to register on this site
!
Scenario: Successful registration when visitor provides all the required info
Given I am on the homepage
When I follow “sign up”
And I fill in registration form
And I submit it
Then I should be successfully registered
And I should be on the homepage again

114. Stories
Examples
Describe
Design
Implement

115. #3: Income

116. 6 months later…

117. #3: Same ashtrays, better car

118. We do that for clients

119. http://
.com
We do that for clients
And teach others in those rare
moments when we don’t