Java 201 Intro to Test Driven Development in Java

Java 201 – Intro to Test-Driven
Development in Java

Agenda
• TDD Overview
• Test Frameworks
• Setting Up your IDE
• Writing your first Unit Test
• Anatomy of a Unit Test
• Hands-on Exercise

Intro to Test-Driven Development
in Java
TDD Overview

TDD Overview
• What is TDD
• Why TDD
• Feedback Loop
• TDD Workflow

What is TDD?
• Technique for specifying system features with
tests
• Tests are written before production code
• Simple, repeated, short-cycled mechanism
• Automated mechanism for regression testing
of code changes

Why TDD?
• Improves code quality
• Minimises defects
• Increases code maintainability
• Reduces the cost of change
• Provides a quick feedback
• Acts as documentation for your code
• Reduces fear of breaking things
• It is fun and infectious 

PDCA Explained
• PLAN
– Establish the objectives
– Identify steps required to meet the objective
• DO
– Execute the steps to meet the objective
• CHECK
– Study actual results and compare against expected results
– Look for completeness in meeting the objectives
• ACT
– If CHECK step shows objectives met vs. with the plan,
repeat with next objective else rework and CHECK again

in Java
Test Frameworks

What is a Test Framework?
• An abstract set of…
– concepts, processes, procedures, environments
• Where automated tests are…
– designed, implemented and executed
• Includes physical structures for…
– test creation
– test execution
• As well as…
– logical interactions amongst components

Why Test Frameworks?
• Provides the basis of test automation
• Simplifies test automation efforts
• Provides concepts and tools that support
automated testing

Common Test Frameworks
• Code Testing
– Junit (http://www.junit.org)
– TestNG (http://testng.org)
• UI Testing
– Selenium (www.selenium.org)
– Appium (http://appium.io/)
• API Testing
– SoapUI (http://www.soapui.org)
– RestAssured (https://code.google.com/p/rest-assured)

in Java
Setting Up your IDE

Setting Up
• Required Software
• Download JUnit
• Create Java201 Project
• Add JUnit to the Classpath
• Create HelloGreetingTest
• Run the HelloGreetingTest
• Create the HelloGreeting class
• Re-run the HelloGreetingTest

Required Software
• IDE
• Java SDK
– http://www.oracle.com/technetwork/java/javase/
downloads/jdk8-downloads-2133151.html
• JUnit
– www.junit.org

Download JUnit
• Download the following files from
www.junit.org to a folder on your hard drive
– junit.jar
– hamcrest-core.jar

Create Java201 Project
• Create new project named Java201
• Create a new source folder named test in the
java201 project
• Create a lib folder in the Java201 project
• In the test source folder, create the
java201.greetings package

Add JUnit to the Classpath
• Copy the junit.jar and hamcrest-core.jar files to
the lib folder of your project
• Refresh the project to import the new contents
of the lib folder
• In Eclipse, click on the Java201 project, select
File>Properties>Build Path and click on
Libraries tab
• Click Add JARs, browse to the project lib folder,
select both jar files and click OK twice

Create HelloGreetingTest.java
• In Eclipse, Right-click the test folder, select New>JUnit Test Case,
enter HelloGreetingTest in the Name field and click Finish

Implement HelloGreetingTest.java

Run the HelloGreetingTest
• In Eclipse, Right-click the HelloGreetingTest and select
Run As>JUnit Test

Create HelloGreeting class
• In Eclipse, right-click the src folder and select New>Class, enter
HelloGreeting as class name and click Finish
• Create a sayHello() method that returns the String “Hello, TDD!”

Re-run the HelloGreetingTest
• Declare and initialise HelloGreeting object and
assert it returns “Hello, TDD!” and rerun the test

Java 201 Intro to Test Driven Development in Java

in Java
Anatomy of a Unit Test

Anatomy of a Unit Test
Declaration of
class under test
setUp() runs once
before each test method
A test method
Initialization of
class under test
tearDown() runs once
after each test method
Checking test results

in Java
Hands-on Exercise

Exercise: Game of Cards
• Using TDD, create the following building blocks of a
typical card game
– Card
• Has a suite (Club, Heart, Diamond, Spade) and rank (2-10, Jack,
Queen, King, Ace)
• Ace is highest card
– Hand
• Consists of one or more Cards
– Deck
• Contains 52 Cards, 13 cards per suite
– Dealer
• Deals cards from a deck
• Each player will be dealt a Hand of Cards

Card
rank
suite
getRank() : Rank
setRank() : void
getSuite() : Suite
setSuite() : void
Hand
cards
maxCards
getNoOfCards() : int
drawCard(): Card
addCard() : void
Deck
cards
getCards(int noOFCards) :
List<Card>
Dealer
deck
deal(noOfCards) : Hand
Game of Cards Domain Model

Solution: Game of Cards
https://github.com/hawkmanacademy/java201

Resources
• UML Distilled - http://amzn.to/1BBHcXi
• Test Driven Development –
http://amzn.to/1xqPllN
• XUnit Patterns - http://xunitpatterns.com/
• Junit – www.junit.org

Java 201 Intro to Test Driven Development in Java

More Related Content

What's hot (12)

Viewers also liked (20)

Similar to Java 201 Intro to Test Driven Development in Java (20)

Recently uploaded (20)

Java 201 Intro to Test Driven Development in Java

Editor's Notes