Unit Testing Subhash Chandran S WizTools.org A Java Programmer's Approach

Testing What the program is supposed to do == What the program actually does

Types Unit Integration / Functional System

Unit

Integration / Functional

System

Unit Testing, Java Style JUnit TestNG (Will not be discussed in this session)

JUnit

TestNG (Will not be discussed in this session)

JUnit Version 3.x Version 4.x – Java 5 and above features

Version 3.x

Version 4.x – Java 5 and above features

What we want to do? Add Remove

How we did it // ShoppingCart.java public class ShoppingCart{ public void add(Product p, int quantity){ ... } public void remove(Product p, int quantity){ ... } } // Tomato.java public class Tomato implements Product{ ... }

Add Test in JUnit 3.x import junit.framework.TestCase; public class ShoppingCartTest extends TestCase { private ShoppingCart cart; public void testAdd (){ cart = new ShoppingCart(); Tomato t = new Tomato(); cart.add(t, 10); // Product and quantity assertEquals (cart.count(), 10); } }

Add Test in JUnit 4.x import org.junit.Test; import static org.junit.Assert.*; public class ShoppingCartTest{ private ShoppingCart cart; @Test public void testAdd() { cart = new ShoppingCart(); Tomato t = new Tomato(); cart.add(t, 10); assertEquals (cart.count(), 10); } }

Remove Test // Add @Test annotation for JUnit 4.x public void testRemove(){ cart = new ShoppingCart(); Tomato t = new Tomato(); cart.add(t, 10); cart.remove(t, 6); assertEquals(cart.count(), 4); }

Test Class public class ShoppingCartTest ... { private ShoppingCart cart; public void testAdd(){ cart = new ShoppingCart(); ... } public void testRemove(){ cart = new ShoppingCart(); ... } } Duplication!

Lifecycle 3.x setUp () testXXX1() tearDown () setUp () testXXX2() tearDown () setUp () testXXX3() tearDown ()

Lifecycle 4.x @ Before @Test XXX1 @ After @ Before @Test XXX2 @ After @ Before @Test XXX3 @ After

Final Test Class public class ShoppingCartTest ... { ... // @org.junit.Before to be added for JUnit 4.x protected void setUp (){ cart = new ShoppingCart(); } // @org.junit.After to be added for JUnit 4.x protected void tearDown (){ cart = null; } // test* methods follow }

Other Assert Methods assertNull(...) assertArrayEquals(..., ...) assertEquals(..., ...) assertSame(..., ...) assertTrue(...) and ”Not” of all the above.

assertNull(...)

assertArrayEquals(..., ...)

assertEquals(..., ...)

assertSame(..., ...)

assertTrue(...)

and ”Not” of all the above.

Our Approach (so far)... We created the domain classes then the test cases to unit test them Another approach...

We created the domain classes

then

the test cases to unit test them

Test Driven Development (TDD) First write the test case Then program domain classes to comply to it What the #@&*?

First write the test case

Then program domain classes to comply to it

When programming... Details, details and more implementation details...

What Tests Do? Tests define the behavior Tests define what you want to achieve Tests define what your program should do

Tests define the behavior

Tests define what you want to achieve

Tests define what your program should do

When All These Are Defined... Your design is beautiful When dealing with implementation details, you will not loose focus You have a execution environment for running your code

Your design is beautiful

When dealing with implementation details, you will not loose focus

You have a execution environment for running your code

So TDD! And save enough time to enjoy Life!

What we covered? Meaning and types of testing JUnit 3.x and 4.x TDD

Meaning and types of testing

JUnit 3.x and 4.x

TDD

Action Item Practice TDD :-) Thanks and Bye! Subhash. subwiz (at) gmail.com

Practice TDD :-)