Software Engineering
●Testing
●Unit-testing
●JUnit

Why testing at all?

Simplest case:
Development => Production
700
600
500
(random numbers, but you get the idea)
400
Bugs found
300
Bugfix Cost
200
100
0
Development Release

Real world
(no testing)
1600
€ 1,500.00
1400
1200
1000
800
Bugs found
Cost per Bug
435
600
400 321
200
€ 200.00
0
Development Production

Real world
(no testing)
1600
321 x 1500 = € 1,500.00 Total:
1400 €481,500 € 568,500
1200
435 x 200 =
1000
800 €87,000 Bugs found
Cost per Bug
435
600
400 321
200
€ 200.00
0
Development Production

Real world
+ testing
121 x 1500 =
1600
€181,500 € 1,500.00 Total:
1400
€ 308,500
1200
635 x 200 =
€127,000
1000
635
800
Bugs found
600
Cost per Bug
400
€ 200.00
200 121
0
Development Production

no testing vs + testing
600000
€ 568,500.00
500000
about a half!
400000
€ 308,500.00
300000
Cost
200000
100000
0
No testing With testing

In the software eng. process...
Imagination Real world
Design Coding

In the software eng. process...
Imagination Real world
GAP
Design ` Coding

In the software eng. process...
Imagination Real world
Design Testing Coding

Continue with examples
 A living cell:
A quick introduction to JUnit, D. Steinberg
http://www.slideshare.net/sundar22in/junit
 Shopping Cart
Unit testing with JUnit, T. Zimmermann
http://www.slideshare.net/tom.zimmermann/unit-testing-with-junit

Let's try it out!

Create a new Java Project

Let's create a model class ...

... an Ad post

Now, a JUnit Class

Call it PostTest,
to follow a name pattern

Confirm to add JUnit library

First things first:
setup() and tearDown()

Add a couple of methods to
our model class

Let's add some tests!

Here we go: Run As => JUnit Test

All tests passed!

Time for the TestSuite

Let's call it PostTestSuite

Use it with PostTest.class

Let's try it out!

Here you have it:
JUnit's Swing GUI

Introducing new model attribute:
price

Reflect that in our TestCase
and re-run JUnit test ...

Oops! Test failed.
failed
Can you figure out why?

Further reading
 JUnit FAQ
http://junit.sourceforge.net/doc/faq/faq.htm
 JUnit
http://www.junit.org