Starting unit testing on a project can seem like a daunting task, and earning team and leadership buy-in can be challenging. We'll walk-through setup with composer, creating the first test, restructuring existing classes with dependency injection to allow unit testing, and releasing code confidently with test coverage. We'll also discuss overcoming common biases, unit testing challenges, and shortcomings of unit testing. Watch the presentation at https://www.youtube.com/watch?v=6v4_bEajDUk

1. Unit Testing from
Setup to Deployment
Mark Niebergall

2. Thank You!
• Entrata - Venue, Food
• JetBrains - 1 free license
• Platform.sh - Zoom

3. https://analyze.co.za/wp-content/uploads/2018/12/441-1170x500.jpg

4. Objective
• Be familiar with how to setup PHPUnit
• Familiar with how to test existing code
• Know how to write unit tests using PHPUnit with
Prophecy
• Convince team and management to leverage automated
testing

5. Overview
• Bene
fi
ts of Unit Testing
• PHPUnit Setup
• Writing Unit Tests
• Testing Existing Code

6. Bene
fi
ts of Unit Testing

7. Bene
fi
ts of Unit Testing
public static function add($a, $b)
{
return $a + $b;
}

8. Bene
fi
ts of Unit Testing
public static function add($a, $b)
{
return $a + $b;
}
public function add(float ...$numbers): float
{
$return = 0;
foreach ($numbers as $value) {
$return = bcadd(
(string) $return,
(string) $value,
10
);
}
return (float) $return;
}

9. Bene
fi
ts of Unit Testing
http://www.ambysoft.com/artwork/comparingTechniques.jpg

10. Bene
fi
ts of Unit Testing
• Automated way to test code
- Regression Testing

11. Bene
fi
ts of Unit Testing
• Automated way to test code
- Continuous Integration
- Continuous Deployment

12. Bene
fi
ts of Unit Testing
• Automated way to test code
- Other ways to automatically test code beside functional
tests
‣ Behavioral tests (behat)
‣ phpspec (functional)
‣ Selenium (browser automation)
‣ Others?

13. Bene
fi
ts of Unit Testing
• Decrease bugs introduced with code
- Decreased time to deployment
- Better use of QA team time

14. Bene
fi
ts of Unit Testing
• Decrease bugs introduced with code
- High con
fi
dence in delivered code

15. Bene
fi
ts of Unit Testing
• Con
fi
dence when refactoring
- Tests covering code being refactored
- TDD
‣ Change tests
‣ Tests fail
‣ Change code
‣ Tests pass

16. PHPUnit Setup

17. PHPUnit Setup
• Install via composer
• Setup `phpunit.xml` for con
fi
guration (if needed)
• Run unit tests

18. PHPUnit Setup
• phpunit/phpunit
• phpspec/prophecy-phpunit
• fakerphp/faker

19. PHPUnit Setup
composer require --dev phpunit/phpunit
composer require --dev phpspec/prophecy-phpunit
composer require --dev fakerphp/faker

20. PHPUnit Setup
• File phpunit.xml
- PHPUnit con
fi
guration for that project
- Documentation: https://phpunit.readthedocs.io/en/9.5/
con
fi
guration.html
<?xml version="1.0" encoding="UTF-8"?>
<phpunit colors="true"
verbose="true"
bootstrap="./tests/Bootstrap.php">
<testsuite name="All Tests">
<directory>./tests</directory>
</testsuite>
</phpunit>

21. PHPUnit Setup
• Running PHPUnit
vendor/bin/phpunit tests/
PHPUnit 9.5.6 by Sebastian Bergmann and contributors.
Runtime: PHP 8.0.8
Con
fi
guration: /Users/mniebergall/projects/training/phpunit/
phpunit.xml
......... 9 / 9 (100%)
Time: 00:00.032, Memory: 6.00 MB
OK (9 tests, 12 assertions)

22. PHPUnit Setup
• Running PHPUnit
- Within PhpStorm

23. PHPUnit Setup
• Directory Structure
- PHP
fi
les in src/
‣ Ex: src/Math/Adder.php
- tests in tests/src/, ‘Test’ at end of
fi
lename
‣ Ex: tests/src/Math/AdderTest.php

24. Writing Unit Tests

25. Writing Unit Tests
public function add(float ...$numbers): float
{
$return = 0;
foreach ($numbers as $value) {
$return = bcadd(
(string) $return,
(string) $value,
10
);
}
return (float) $return;
}

26. Writing Unit Tests
use PHPUnitFrameworkTestCase;
class AdderTest extends TestCase
{
protected Adder $adder;
public function setUp(): void
{
$this->adder = new Adder();
}
public function testAdderWithSetup()
{
$sum = $this->adder->add(3, 7);
$this->assertSame(10.0, $sum);
}

27. Writing Unit Tests
public function testAdderThrowsExceptionWhenNotANumber()
{
$this->expectException(TypeError::class);
$adder = new Adder();
$adder->add(7, 'Can't add this');
}

28. Writing Unit Tests
public function testAdderAddsIntegers()
{
$adder = new Adder();
$sum = $adder->add(7, 3, 5, 5, 6, 4, 1, 9);
$this->assertSame(40.0, $sum);
}
public function testAdderAddsDecimals()
{
$adder = new Adder();
$sum = $adder->add(1.5, 0.5);
$this->assertSame(2.0, $sum);
}

29. Writing Unit Tests
/**
* @dataProvider dataProviderNumbers
*/
public function testAdderAddsNumbers(
float $expectedSum,
...$numbers
) {
$adder = new Adder();
$sum = $adder->add(...$numbers);
$this->assertSame($expectedSum, $sum);
}
public function dataProviderNumbers(): array
{
return [
[2, 1, 1],
[2, 1.5, 0.5],
];
}

30. Writing Unit Tests
• Test Coverage
- Percent of code covered by tests
- Not aiming for 100%
- No need to test language constructs

31. Writing Unit Tests
• Code should be self-contained
- No actual database connections
- No API calls should occur
- No external code should be called
‣ Use testing framework

32. Writing Unit Tests
• Assertions
$this->assertInstanceOf(Response::class, $response);
$this->assertEquals(200, $response->getStatusCode());
$this->assertSame(401, $responseActual->getStatusCode());
$this->assertTrue($dispatched);
$this->assertFalse($sent);

33. Writing Unit Tests
• Assertions
$this->expectException(RuntimeException::class);
$this->expectExceptionCode(403);
$this->expectExceptionMessage(‘Configuration not found.');

34. Writing Unit Tests
• Prophecy
- Mock objects
- Expected method calls
- Reveal object when injecting
use PHPUnitFrameworkTestCase;
use ProphecyPhpUnitProphecyTrait;
class RectangleTest extends TestCase
{
use ProphecyTrait;

35. Writing Unit Tests
• Prophecy
$adderMock = $this->prophesize(Adder::class);
$multiplierMock = $this->prophesize(Multiplier::class);
$adderMock->add($length, $width)
->shouldBeCalled()
->willReturn(10.34001);
$multiplierMock->multiply(2, 10.34001)
->shouldBeCalled()
->willReturn(20.68002);
$rectangle = new Rectangle(
$length,
$width,
$adderMock->reveal(),
$multiplierMock->reveal()
);

36. Writing Unit Tests
• Prophecy
$dbMock->fetchRow(Argument::any())
->shouldBeCalled()
->willReturn([]);
$asyncBusMock
->dispatch(
Argument::type(DoSomethingCmd::class),
Argument::type('array')
)
->shouldBeCalled()
->willReturn((new Envelope(new stdClass())));

37. Testing Existing Code

38. Testing Existing Code
• Problematic Patterns
- Long and complex functions

39. Testing Existing Code
• Problematic Patterns
- Missing Dependency Injection (DI)
‣ `new Thing();` in functions to be tested

40. Testing Existing Code
• Problematic Patterns
- exit and die
- print_r
- var_dump
- echo
- other outputs in-line

41. Testing Existing Code
• Problematic Patterns
- Database interactions
- Resources

42. Testing Existing Code
• Problematic Patterns
- Out of classes code execution
- Functional code

43. Testing Existing Code
• Helpful Patterns
- Unit testing promotes good code patterns

44. Testing Existing Code
• Helpful Patterns
- Dependency Injection
- Classes and functions focused on one thing
- Abstraction
- Interfaces
- Clean code

45. Testing Existing Code
• Helpful Patterns
- Code that is SOLID
‣ Single-responsibility: should be open for extension,
but closed for modi
fi
cation
‣ Open-closed: should be open for extension, but
closed for modi
fi
cation
‣ Liskov substitution: in PHP, use interface/abstract
‣ Interface segregation: Many client-speci
fi
c interfaces
are better than one general-purpose interface
‣ Dependency inversion: Depend upon abstractions,
[not] concretions

46. Testing Existing Code
• Helpful Patterns
- KISS

47. Testing Existing Code
• Test Coverage
- Percent of code covered by tests
- Not aiming for 100%
- No need to test language constructs
- Outputs report in various formats
- Uses Xdebug as driver

48. Testing Existing Code
class ShapeService
{
public function create(string $shape): int
{
$db = new Db();
return $db->insert('shape', ['shape' => $shape]);
}
public function smsArea(Rectangle $shape, string $toNumber): bool
{
$sms = new Sms([
'api_uri' => 'https://example.com/sms',
'api_key' => 'alkdjfoasifj0392lkdsjf',
]);
$sent = $sms->send($toNumber, 'Area is ' . $shape->area());
(new Logger())
->log('Sms sent to ' . $toNumber . ': Area is ' . $shape->area());
return $sent;
}
}

49. Testing Existing Code
class ShapeService
{
public function create(string $shape): int
{
$db = new Db();
return $db->insert('shape', ['shape' => $shape]);
}
public function smsArea(Rectangle $shape, string $toNumber): bool
{
$sms = new Sms([
'api_uri' => 'https://example.com/sms',
'api_key' => 'alkdjfoasifj0392lkdsjf',
]);
$sent = $sms->send($toNumber, 'Area is ' . $shape->area());
(new Logger())
->log('Sms sent to ' . $toNumber . ': Area is ' . $shape->area());
return $sent;
}
}

50. Testing Existing Code
class ShapeServiceCleanedUp
{
public function __construct(
protected Db $db,
protected Sms $sms
) {}
public function create(string $shape): int
{
return $this->db->insert('shape', ['shape' => $shape]);
}
public function smsArea(ShapeInterface $shape, string $toNumber): bool
{
$area = $shape->area();
return $this->sms->send($toNumber, 'Area is ' . $area);
}

51. Testing Existing Code
use ProphecyTrait;
protected Generator $faker;
public function setUp(): void
{
$this->faker = Factory::create();
}
public function testCreate()
{
$dbMock = $this->prophesize(Db::class);
$smsMock = $this->prophesize(Sms::class);
$shape = $this->faker->word;
$dbMock->insert('shape', ['shape' => $shape])
->shouldBeCalled()
->willReturn(1);
$shapeServiceCleanedUp = new ShapeServiceCleanedUp(
$dbMock->reveal(),
$smsMock->reveal()
);
$shapeServiceCleanedUp->create($shape);
}

52. Testing Existing Code
public function testSmsArea()
{
$dbMock = $this->prophesize(Db::class);
$smsMock = $this->prophesize(Sms::class);
$shapeMock = $this->prophesize(ShapeInterface::class);
$area = $this->faker->randomFloat();
$shapeMock->area()
->shouldBeCalled()
->willReturn($area);
$toNumber = $this->faker->phoneNumber;
$smsMock->send($toNumber, 'Area is ' . $area)
->shouldBeCalled()
->willReturn(1);
$shapeServiceCleanedUp = new ShapeServiceCleanedUp(
$dbMock->reveal(),
$smsMock->reveal()
);
$shapeServiceCleanedUp->smsArea(
$shapeMock->reveal(),
$toNumber
);
}

53. Live Examples

54. Discussion Items
• Convincing Teammates
• Convincing Management

55. Discussion Items
• Does unit testing slow development down?

56. Discussion Items
• “I don’t see the bene
fi
t of unit testing”

57. Discussion Items
• Unit tests for legacy code

58. Discussion Items
• Other?

59. Review
• Bene
fi
ts of Unit Testing
• PHPUnit Setup
• Writing Unit Tests
• Testing Existing Code

60. Unit Testing from Setup to Deployment
• Questions?

61. Mark Niebergall @mbniebergall
• PHP since 2005
• Masters degree in MIS
• Senior Software Engineer
• Drug screening project
• Utah PHP Co-Organizer
• CSSLP, SSCP Certi
fi
ed and SME
• Endurance sports, outdoors

62. References
• https://analyze.co.za/wp-content/uploads/
2018/12/441-1170x500.jpg
• http://www.ambysoft.com/artwork/
comparingTechniques.jpg
• https://en.wikipedia.org/wiki/SOLID