The document discusses best practices for unit testing PHP code with PHPUnit. It provides examples of unit tests for an Account class and demonstrates how to structure tests to focus on testing one thing at a time, use data providers for repetitive tests, isolate dependencies, and annotate tests with @covers to specify code coverage. Following these practices helps ensure tests are maintainable, readable, and effective at testing code functionality.

1. Practical Approach
for testing your
software with PHPUnit
Mario Bittencourt

2. Agenda
 Current situation
 PHPUnit as part of the solution
 Best Practices

3. Current situation

4. Complexity, dependencies
and pace over time

5. Software Development
Life Cycle

6. Testing
 Tedious
 Can only cover a small subset of the use cases
 Takes a lot of time
 Change the code to test it

7. Automation is key
Goal is to create tests that can be executed
automatically to verify that the expected behaviour
is met

8. PHPUnit as part
of the solution

9. Example
class Account
{
protected $balance;
public function __construct($initialAmount)
{
$this->balance = $initialAmount;
}
public function getBalance()
{
return $this->balance;
}
public function deposit($amount)
{
$this->balance += $amount;
}
}

10. Unit Test
class AccountTest extends PHpUnit_Framework_TestCase
{
public function testDepositIncreasesBalance()
{
$account = new Account(10);
$account->deposit(1);
$this->assertEquals(11, $account->getBalance());
}
}

11. Unit Test
PHPUnit 4.3.1 by Sebastian Bergmann.
Account
[x] Deposit increases balance

12. Best Practices

13. Give meaningful names to your
tests
public function testDeposit()
{
$account = new Account(10);
$account->deposit(1);
$this->assertEquals(
11,
$account->getBalance()
);
}
 DON’T

14. Give meaningful names to your
tests
PHPUnit 4.3.1 by Sebastian Bergmann.
Account
[ ] Deposit

15. Give meaningful names to your
tests
public function testDepositIncreaseBalance()
{
$account = new Account(10);
$account->deposit(1);
$this->assertEquals(
11,
$account->getBalance()
);
}

16. Use the most specific
assertion available
public function testDepositIncreasesBalance()
{
$account = new Account(10);
$account->deposit(10);
$this->assertGreaterThan(
10,$account->getBalance()
);
}
 DON’T

17. Use the most specific
assertion available
public function testDepositIncreasesBalance()
{
$account = new Account(10);
$account->deposit(10);
$this->assertEquals(20, $account->getBalance());
}

18. Use the most specific
assertion available
public function deposit($amount)
{
$this->balance += $amount;
if ($amount >= 10) {
$this->balance += 1;
}
return true;
}

19. Use the most specific
assertion available
There was 1 failure:
1) AccountTest::testDepositIncreasesBalance
Failed asserting that 21 matches expected 20.
AccountTest.php:14

20. Don’t forget about protected
methods
class Account
{
public function deposit($amount)
{
if ($this->validateAmount($amount)) {
$this->balance += $amount;
} else {
throw new Exception('Invalid amount');
}
}
}

21. Don't forget about
your protected methods
protected function validateAmount($amount)
{
if ($amount < 0) {
return false;
} else {
return true;
}
}

22. Don't forget about
your protected methods
public function testValidateAmountWithNegativeIsFalse()
{
$account = new Account(10);
$this->assertFalse($account->validateAmount(-1));
}
Fatal error: Call to protected method Account::validateAmount()

23. Don't forget about
your protected methods
public function testValidateAmountWithNegativeIsFalse()
{
$account = new Account(10);
$reflection = new ReflectionObject($account);
$method = $reflection->getMethod('validateAmount');
$method->setAccessible(true);
$this->assertFalse(
$method->invokeArgs($account, array(-1))
);
}

24. Don't forget about
your protected methods
PHPUnit 4.3.1 by Sebastian Bergmann.
Account
[x] Deposit increases balance
[x] Validate amount with negative is false

25. Test just one thing at a time
public function deposit($amount)
{
if ($amount == 0) {
return false;
}
$this->balance += $amount;
return true;
}

26. Test just one thing at a time
public function testDepositIncreasesBalance()
{
$account = new Account(10);
$this->assertTrue($account->deposit(1));
$this->assertEquals(11, $account->getBalance());
$this->assertFalse($account->deposit(0));
}

27. Test just one thing at a time
PHPUnit 4.3.1 by Sebastian Bergmann.
.
Time: 35 ms, Memory: 3.00Mb
OK (1 test, 3 assertions)

28. Test just one thing at a time
public function deposit($amount)
{
if ($amount < 0) {
NEW CRITERIA
return false;
}
$this->balance += $amount;
return true;
}

29. Test just one thing at a time
PHPUnit 4.3.1 by Sebastian Bergmann.
There was 1 failure:
1) AccountTest::testDepositIncreasesBalance
Failed asserting that true is false.
AccountTest.php:15
FAILURES!
Tests: 1, Assertions: 3, Failures: 1.

30. Test just one thing at a time
public function testDepositIncreasesBalance()
{
$account = new Account(10);
$this->assertTrue($account->deposit(1));
$this->assertEquals(11, $account->getBalance());
}
public function
testDepositWithNegativeShouldReturnFalse()
{
$account = new Account(10);
$this->assertFalse($account->deposit(-1));
}

31. Test just one thing at a time
PHPUnit 4.3.1 by Sebastian Bergmann.
..
Time: 49 ms, Memory: 3.00Mb
OK (2 tests, 3 assertions)

32. Use Data Providers for
repetitive tests
class Score
{
protected $score;
public function update($balance, $numberCc,
$amountInLoans)
{
// do something ...
return $newScore;
}
}

33. Use Data Providers for
repetitive tests
class ScoreTest extends PHpUnit_Framework_TestCase
{
public function testScoreSomething1()
{
$score = new Score(10);
$this->assertEquals(300, $score->update(100, 0, 1));
}
public function testScoreSomething2()
{
$score = new Score(10);
$this->assertEquals(99, $score->update(100, 1, 2));
}
}

34. Use Data Providers for
repetitive tests
/**
* @dataProvider scoreProvider
*/
public function testScore($balance, $numberCc,
$amountInLoans, $expectedScore)
{
$score = new Score(10);
$this->assertEquals(
$expectedScore,
$score->update($balance, $numberCc, $amountInLoans)
);
}

35. Use Data Providers for
repetitive tests
public function scoreProvider()
{
return array(
array(100, 0, 1, 300),
array(100, 1, 2, 99),
);
}

36. Use Data Providers for
repetitive tests
PHPUnit 4.3.1 by Sebastian Bergmann.
..
Time: 25 ms, Memory: 3.00Mb
OK (2 tests, 2 assertions)

37. Isolate your test
public function wire($amount, SwiftInterface $targetBank)
{
if ($targetBank->transfer($amount)) {
$this->balance -= $amount;
return true;
} else {
return false;
}
}

38. Isolate your test
class Hsbc implements SwiftInterface {
public function transfer($amount)
{
// slow method
}
}

39. Isolate your test
public function
testWireTransferShouldReturnTrueIfSuccessful()
{
$account = new Account(10);
$bank = new Hsbc();
$this->assertTrue($account->wire(5, $bank));
}

40. Isolate your test
public function
testWireTransferShouldReturnFalseIfFailed()
{
// how to fail?
$account = new Account(10);
$bank = new Hsbc();
$this->assertFalse($account->wire(5, $bank));
}

41. Isolate your test
public function
testWireTransferShouldReturnTrueIfSuccessful()
{
$account = new Account(10);
$bank = $this->getMock(‘Hsbc');
$bank->expects($this->any())
->method('transfer')
->will($this->returnValue(true));
$this->assertTrue($account->wire(5, $bank));
}

42. Isolate your test
public function
testWireTransferShouldReturnFalseIfFailed()
{
$account = new Account(10);
$bank = $this->getMock('Hsbc');
$bank->expects($this->any())
->method('transfer')
->will($this->returnValue(false));
$this->assertFalse($account->wire(5, $bank));
}

43. Specify what you are testing
with @covers
 Use --coverage-html to generate the code
coverage report of your code

44. Specify what you are testing
with @covers

45. Specify what you are testing
with @covers
class Exchange {
public function convert($amountUsd, $targetCurrency)
{
// Do some conversion
}
}

46. Specify what you are testing
with @covers
public function convertBalance($targetCurrency)
{
$exchange = new Exchange();
return $exchange->convert($this->balance, $targetCurrency);
}

47. Specify what you are testing
with @covers
public function testConvertBalance()
{
$account = new Account(10);
$this->assertLessThan(
10, $account->convertBalance('GBP')
);
}

48. Specify what you are testing
with @covers

49. Specify what you are testing
with @covers

50. Specify what you are testing
with @covers
/**
* @covers Account::convertBalance
*/
public function testConvertBalance()
{
…
}

51. Specify what you are testing
with @covers

52. That is all folks!
Contacts
 Twitter -@bicatu
 Email – mbneto@gmail.com
 https://joind.in/12279
 http://slidesha.re/1xtcT4y