Test driven development (TDD) involves writing tests before writing code to define requirements and ensure code meets those requirements. The presentation introduces TDD and related concepts like the red-green-refactor cycle, unit tests, integration tests, Gherkin for requirements gathering, and popular tools for TDD in different programming languages.

1. INTRODUCTION TO
TEST DRIVEN DEVELOPMENT
Presented by Sarah Dutkiewicz
sarah@cletechconsulting.com

2. AGENDA
• Test Driven Development – What does this mean?
• Gathering Requirements
• Gherkin
• Tools for TDD in the Workplace

3. WHAT IS
TEST DRIVEN
DEVELOPMENT?

4. TEST DRIVEN DEVELOPMENT
• Define {something} first through a test
• Write the code to pass the test
• Verify that the test succeeds
• Improve upon the code and keep the test passing

5. Write the
test
Write the
code to
pass the test
Improve the
code while
keeping the
test passing
RED-GREENREFACTOR

6. EXAMPLE – RUBY KOANS

7. EXAMPLE – RUBY KOANS

8. TDD CONCEPT - ASSERTIONS
• Verify whether a certain condition has been met
• Asserts come in many forms:
•
•
•
•
•
•
(Not) Equal
Contains / Any
Is a Type
Is an Instance of a Type
Is (Not) Null
Is (True/False)
• Design Guideline – One assert per test

9. TDD CONCEPT –
ARRANGE/ACT/ASSERT
• Pattern for arranging a test
1. Arrange all preconditions and inputs.
2. Act on the object or method.
3. Assert that the results have occurred.

10. TEST-DRIVEN – TYPES OF TESTS
Tests, Tests, and More Tests… Oh My!

11. TYPES OF TESTS
• Unit Tests
• Integration Tests
• End-to-End Tests
• Exploratory Testing

12. UNIT TESTS
• Focus on a class or a method
• Tests the smallest unit possible
• Typically tests simple objects; does not
test things such as:
• Database communication
• Network communication
• File system manipulation

13. INTEGRATION TESTS
• Tests functions, “does things”
• Tests interactions with the outside world, include:
• Database communication
• Network communication
• File system manipulation
• Focused integration tests isolate the testing to
one interaction at a time
• Integration tests should run on their own, with a
little help from 2 fundamental units:
• Setup – run at the beginning of the test to set
up the test environment
• Tear-down – run at the end of the test or upon
error to clean up the test environment

14. END-TO-END TESTS
• The most brittle of tests –
dependent on the big picture
• Verifies that the unit tests and
integration tests are working like
they should
• Start at the beginning and go
through the whole process
• Includes:
• Acceptance testing
• Functional testing

15. EXPLORATORY TESTING
• Not an automated process; manual testing
• Sometimes better to go this route rather than end-to-end tests – depending
on the design and architecture of your application
• EXPLORE!
• Discovery
• Investigation
• Learning

16. MORE *-DRIVEN DEVELOPMENT
Related philosophies and methodologies

17. OTHER RELATED *-DRIVEN
DEVELOPMENT
• Behavior Driven Development
• Acceptance Test Driven Development
• Specification by Example

18. ACCEPTANCE TEST DRIVEN DEVELOPMENT CYCLE
Discuss the
requirements
Distill the tests in
a friendly
format
Demo the code
Develop the
code (and
hook the code
to the tests)

19. ATDD AND THE TDD CYCLE
REFACTOR
Discuss the
requirements
Distill the tests in
a friendly
format
Demo the code
GREEN
RED
Develop the
code (and
hook the code
to the tests)
GREEN

20. GATHERING
REQUIREMENTS
The Importance of TDD & ATDD for the UX Realm and an Intro to Gherkin

21. DISCUSS
• Conducted by all who are involved:
•
•
•
•
Product owners
Business analysts
Developers
QA
• Requirements are explicitly spelled out.
• Include use cases.
• Include required behaviors or designs.

22. GHERKIN
• Common language for gathering requirements
• Written in “plain English” following a particular cadence
• Can then be hooked up to various programming languages and testing
tools
• Serves as guidelines for automated tests as well as project documentation

23. GHERKIN COMPONENTS
• Features
• Scenarios & Scenario
Outlines
• Backgrounds
• Steps
• Multiline Arguments
• Tags

24. FEATURES
• Define a feature of an application
• Starts with the Feature keyword and contains a few lines to define the feature
Example:
Feature: Short, concise, descriptive text of the goal
In order to do something
As someone related to this system
I want to gain something out of this
* Features are stored in a *.feature file

25. FEATURE EXAMPLE
Feature: Checking out books
In order to read eBooks on my eBook reader,
As a library patron,
I want to check out eBooks.

26. SCENARIOS
• Possibilities of situations (scenarios) that apply to a feature
• Scenarios are included in *.feature files with their relevant feature
• Created with one or more steps

27. SCENARIO EXAMPLE
Scenario: Checking out a book
Given the library collection has the book I want to check out
When I check out the book
Then the library collection’s available count is reduced by 1

28. STEPS
• Given a certain given condition
• When a certain behavior happens
• Then a certain outcome is expected
• Additional keywords include But and And
•
•
•
•
Given a certain given condition
And another given condition
When a certain behavior happens
Then a certain outcome is expected

29. SCENARIO OUTLINES
• Scenario Outlines eliminate the need for copying and pasting like scenarios
and collapsing values into variables.
• Rather than starting with Scenario, it starts with Scenario Outline.
• Variables (placeholders) are denoted with names sandwiched in greaterthan and less-than symbols.

30. SCENARIO OUTLINE EXAMPLE
Scenario Outline: Checking book checkout expiration
Given a checkout period of <checkout_period> days
When I open the book at day <open>
Then the book should expire in <left> days
Examples:
| checkout_period | open
| left |
|7
|2
|5
|
| 14
| 10
|2
|
| 21
| 18
|3
|

31. MULTILINE ARGUMENTS
• Tables
Example:
Scenario:
Given the following accounts exist:
|name
|email
|account_type|
| Laura
|laura@domain.com | Admin
|
| Sarah
|sarah@domain.com | Admin
|
| Kevin
| kevin@domain.com | User
|

32. MULTILINE ARGUMENTS
• Large paragraph of text
Example:
Scenario:
Given a description search with:
"""
It was the best of times
It was the worst of times
"""

33. BACKGROUNDS
• Backgrounds setup the environment for all scenarios in a feature file.
• Starts with the Background keyword and is typically made up of Given, And,
and But clauses
• Runs before individual scenario setup routines

34. BACKGROUND EXAMPLE
Feature: Checkout eMaterials
Background:
Given a customer named “Sarah Dutkiewicz“
And a library card numbered “12345678901”
And a checkout queue of books:
| title
| author
|
| Hop on Pop
| Dr. Seuss
|
| Harold and the Purple Crayon
| Crockett Johnson |
| Shark Tales: How I Turned $1,000 into a Billion Dollar Business | Barbara Corcoran|

35. TAGS
• Used for grouping like tests, scenarios, and/or features together
• Starts with a @, followed by the tag name
Examples:
@UI @accounting @security
• Many test runners support tags and allow collections of tests to be run by tag

36. TOOLS FOR TDD IN THE
WORKPLACE

37. GHERKIN LANGUAGE RESOURCES
AND GENERAL TDD RESOURCES
• Behat – Writing Features – Gherkin Language
• The Art of Agile Development: Test-Driven Development
• Test first != TDD
• Driving Development with Tests: ATDD and TDD
• Let’s Explore – Exploratory Testing

38. .NET TDD RESOURCES
• SpecFlow – Behavior Driven Development,
Acceptance Test Driven Development,
Specification by Example; includes support for
Silverlight, Windows Phone, and Mono
• TestDriven.Net – Visual Studio integration for unit
tests
• WatiN – Web Application Testing in .NET
• TestStack.White – UI automation testing
• Telerik Test Studio
• Nunit
• MbUnit
• MSTest
• NCover
• TypeMock

39. JAVASCRIPT TDD RESOURCES
• QUnit
• Jasmine
• Zombie.js
• Mocha
• Tutti
• JSTestDriver
• jsUnity
• CasperJS

40. RUBY TDD RESOURCES
• Cucumber – behavior driven
development
• Watir – Web Application Testing in
Ruby
• Ruby Koans – learn Ruby via testing
• Rspec – primary Ruby testing tool

41. PHP TDD RESOURCES
• Behat – behavior driven development
• Mink – web acceptance testing
• PHPUnit
• SimpleTest
• Phpt
• Gouette – headless browser, web scraper

42. JAVA TDD RESOURCES
• JUnit
• Watij – Web Application
Testing in Java
• AppPerfect Java Unit Test

43. ADDITIONAL *DD RESOURCES
• Sahi – JavaScript browser controller
• Selenium – supports C#, Java, Perl,
PHP, Python, Ruby
• Fitnesse – supports multiple languages
• Windmill – supports Python, JavaScript,
Ruby
• Canoo WebTest – supports Python,
JavaScript
• TSQLUnit – TDD for Transact-SQL
• TST – the T-SQL Test Tool

44. CONTACT INFORMATION
Sarah Dutkiewicz
Cleveland Tech Consulting, LLC
sarah@cletechconsulting.com
Twitter: @sadukie
Blog: http://codinggeekette.com