Unit Testing is for
Weenies.
Important lessons learned from being a bullheaded developer...

Unit Testing 101
What are these units and why do they need testing?

What is Unit
Testing?
In computer programming, unit testing is a soft ware verification and
validation method where the programmer gains confidence that individual
units of source code are fit for use. A unit is the smallest testable part of an
application. In procedural programming a unit may be an individual program,
function, procedure, etc., while in object-oriented programming, the smallest
unit is a method, which may belong to a base/super class, abstract class or
derived/child class.
http://en.wikipedia.org/wiki/Unit_testing

No, really. What is
Unit Testing...?

Assertion Testing
IF the assertion fails,
THEN display an error message...

Why should we test?
To ensure repeatability of desired behaviors
To identify and remove undesired behaviors
To provide specifications for expected behavior

Why should I spend time
testing my code?
How do you know that it works, particularly if
it’s part of a big system?
How do you know which part is broken when it
breaks?
How do you know that you know which part is
broken?

There just isn’t enough time
for testing!
How much time do we spend...
Debugging a script or application?
Finding the actual bug?
How many billable hours do we lose?
!?!
Don’t we make our own schedules?

I always test my code...
$newThing = new Thing();
$newThing->doSomething();
$newThing->doSomething($else);
if ( $newThing->something == $else ) {
echo “All done!”
}

I always test my code...
How can anyone ever repeat that test?
What did it test, anyway?
What do you have to show for the effort?

How should we test?
With the least amount of required human
inter vention
In a manner that is reliably repeatable, AKA
“precise”
In a manner that demonstrates desirable
behavior, AKA “
accurate”

No, really. HOW?

How to Perform Unit
Tests on Objects

1. Pick a test fixture...
2. Start writing tests...
3. Run your tests...
4. Repeat until done...

Gee, Thanks.
How about an example?

Doesn’t that seem
repetitive?
I’m glad you asked...

Testing is so repetitive...

Testing is so repetitive...
Unit Tests test Objects.
Objects have Inheritance.
Unit Tests are themselves Objects.
Don’t Repeat Yourself.

How to Sell Your Boss
on Unit Testing
It’s not me, it’s the psycho I work for...

The Essence of Quality
Control is Testing
Testing adds value to work and products
Lessons from other industries...
Toyota makes Good Automobiles.
Sam Adams makes Good Beer.
Unit Testing is Quality Control.

Quality Control Testing
MUST BE
Rigorous, by testing everything,
Repeatable, via automated tests,
Producible upon demand,
Rigorous, repeatable, producible tests generate a more
stable code base and a more accountable project.

Testing actually saves time
and money
Spend less time on tail-end debugging and finding
those bugs,
Expose logical flaws and assumptions that we all
unintentionally build on,
Build dependencies that work since they’re based
on proven assumptions.

Topics to ask Google and
Wikipedia about...
JUnit - The granddaddy of ‘em all.
phpUnit - My torture chamber of choice.
RSpec - Unit Testing for Ruby.
Selenium - Graphical Unit Testing.
Test-Driven Development - Way of Life.

Who is this guy?
linkedin.com/in/althex
t witter.com/al_the_x
ethos-development.com David Rogers
orlandophp.org