Introduction to Testing and TDD

INTRODUCTION TO
TESTING
Presented by Sarah Dutkiewicz
sarah@cletechconsulting.com

AGENDA
• What is Testing?
• Test Driven Development – What does this mean?
• Gathering Requirements
• Gherkin
• Tools for TDD in the Workplace
• Testing & Legacy Code

WHAT IS TESTING?
• Identifying as many use cases as possible
• Making sure actual interactions match expected interactions

Extra Lines of Code
More Time to Write

UI Tests
Service Tests
Unit Tests
More integration
More isolation
Slower
Faster
The Test Pyramid - Succeeding with Agile, Mike Cohn

UI Tests
Integration
Unit Tests
More integration
More isolation
Slower
Faster

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

TYPES OF TESTS
• Unit Tests
• Integration Tests
• Regression / End-to-End Tests
• Performance Tests
• Stress/Load Tests
• Functional Tests
• Acceptance Tests
• Usability Tests
• Manual Testing
• Alpha / Beta Tests
• Exploratory Testing

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

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

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

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

WHAT IS
TEST DRIVEN
DEVELOPMENT?

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

Write the test
Write the
code to pass
the test
Improve the
code while
keeping the
test passing
RED-GREEN-
REFACTOR

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

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.

CODING KATAS
• Ways to practice testing and TDD
• Good for doing pair programming
• Have someone write the test
• Have someone else write the code to pass the test

DEMO – FIZZBUZZ KATA
Live Coding Example

MORE *-DRIVEN DEVELOPMENT
Related philosophies and methodologies

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

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

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

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

• 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.
DISCUSS

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

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

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

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.

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

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

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

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 greater-than and
less-than symbols.

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 |

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
" " "

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

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

DEMO – BOWLING KATA WITH SPECFLOW
SpecFlow Demos at: github.com/techtalk/SpecFlow-Examples

“WRITE AS YOU GO”
Existing
Code Base

TOOLS FOR TDD IN THE
WORKPLACE

TESTING, GHERKIN LANGUAGE RESOURCES AND
GENERAL TDD RESOURCES
• Ministry of Testing
• Gherkin Language Reference
• The Art of Agile Development: Test-Driven
Development
• Test first != TDD
• Let’s Explore – Exploratory Testing

.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
• TestStack.White – UI automation testing
• Visual Studio and Testing Tools
• Nunit
• MbUnit
• NCover
• TypeMock
• Rhino Mocks

JAVASCRIPT TDD RESOURCES
• QUnit
• Jasmine
• Zombie.js
• Mocha
• Chai

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

JAVA TDD RESOURCES
• JUnit
• Watij – Web Application
Testing in Java
• Mockito

PYTHON TESTING RESOURCES
• Obey the Testing
Goat
• pytest docs
• Python unit testing
with Pytest and
Mock
• The Hitchhiker’s
Guide to Python:
Testing Your Code

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

CODING KATAS
• Coding Dojo Kata Catalogue
• Soap UI Testing Katas
• CodeKatas.org
• CodeKata.com
• Testing-Challenges.org

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

Introduction to Testing and TDD

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