TestingTrust your code

About me

MANEL SELLÉS

Software engineerat Ulabox

FIBer

@manelselles

Testing

Do the right thing VS

do the thing right

Testing

What is testing?

Testing

Testing

Why is it usefull?

Testing

● Say it once, check every time automatically.○ “Don’t do repetitive checks”

● Increase reliability and quality of software.○ “I didn’t think of that!”

● Discover regressions in software.○ “Why did it break?”

● Improve confidence in our code.○ “I think this will work.”

Testing

TestingVS

Debugging

Testing

Testing

Example

Testing

Fibonacci● 0 : 0● 1 : 1● 2 : 1● 3 : 2● 4 : 3● 5 : 5● 30 : 832040● 40 : 102334155● 102 : 927372692193078999

Testing

/**

* Fibonacci using an iterative approach

*/

public function fibonacci($n)

{

$a = 0;

$b = 1;

for ($i = 0; $i < $n; $i++) {

$c = $a;

$a = $b;

$b += $c;

}

return $a;

}

Testing

function testFibonacci()

{

echo ($this->fibonacci(0) === 0) === TRUE;

echo ($this->fibonacci(1) === 1) === TRUE;

echo ($this->fibonacci(2) === 1) === TRUE;

echo ($this->fibonacci(3) === 2) === TRUE;

echo ($this->fibonacci(4) === 3) === TRUE;

echo ($this->fibonacci(5) === 5) === TRUE;

echo ($this->fibonacci(30) === 832040) === TRUE;

echo ($this->fibonacci(40) === 102334155) === TRUE;

echo ($this->fibonacci(102) === 927372692193078999) === TRUE;

}

Testing

class FibonacciTest extends PHPUnit_Framework_TestCase{

function testFibonacci(){

$this->assertEquals($this->fibonacci(0), 0);

$this->assertEquals($this->fibonacci(1), 1);

$this->assertEquals($this->fibonacci(2), 1);

$this->assertEquals($this->fibonacci(3), 2);

$this->assertEquals($this->fibonacci(4), 3);

$this->assertEquals($this->fibonacci(5), 5);

$this->assertEquals($this->fibonacci(30), 832040);

$this->assertEquals($this->fibonacci(40), 102334155);

$this->assertEquals($this->fibonacci(102), 927372692193078999);

}}

Testing

/**

* Fibonacci using recursion

*/

public function fibonacci($n)

{

if ($n == 0) {

return 0;

}

if ($n == 1) {

return 1;

}

return $this->fibonacci($n - 1) + $this->fibonacci($n - 2);

}

Testing

Assertions● assertEquals● assertEmpty● assertSame● assertInstanceOf ● assertArrayHasKey● assertArrayHasSubset● assertCount● assertNull

Testing

Coverage

Testing

Testing

Test doubles(to substitute dependencies)

Testing

Without behaviour● Dummy -> no content● Stub -> to guide the test

With behaviour● Fake -> to simulate● Spy -> a call has been made● Mock -> ensure expectation

Testing

Testable Code

Testing

● Global can not be substituted○ Avoid static and singleton

● It’s easier to fake collaborators○ Composition over inheritance○ Isolate dependencies○ Inject dependencies

● It’s easier to test small and one-responsibility classes○ Single responsibility principle

Testing

Test Driven Development

(TDD)

Testing

Testing

QA/tester/developer

ThanksMay the test be with you