This document discusses unit testing PHP code. It begins by introducing the author and their experience with PHP and WordPress. It then discusses different types of testing including functionality, integration, and unit testing. The bulk of the document focuses on unit testing PHP code using PHPUnit - it discusses installing and setting up PHPUnit, writing test classes and methods, the three steps of setup, act, and verify in test cases, and using mocks in tests. The document provides examples of writing PHPUnit tests and ends by listing some PHPUnit tips.

1. Unit Testing PHP code
Sudar Muthu
http://sudarmuthu.com
https://github.com/sudar

2. Me
• Programming in PHP for more than a decade
• Programming in WordPress for 8 years
• Big fan of automating process and workflows
• Occasionally contribute to open source projects
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3. What about you?
• What is your typical development environment
looks like?
• What is your experience with PHP?
• What is your experience with Unit Testing?
• What are your expectations out of this talk?
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4. Is there something wrong?
class Sample {
protected $value;
public function initialize($value) {
$this->value = $value;
}
public function execute() {
if (!$this->value) {
throw new Exception("value not set");
}
return $value * 10; // business logic
}
}
$sample = new Sample;
$sample->execute();
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5. Finding bugs is not
easy
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6. Write Tests
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7. Write Tests
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It sounds obvious but getting started is the hardest part!

8. Different types of Testing
• Functionality testing
• Integration testing
• Unit testing
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9. Different types of Testing
• Functionality testing
• Integration testing
• Unit testing
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10. Briefly
• What is PHPUnit?
• Installing PHPUnit
• Setting up folder structure
• phpunit.xml
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11. Test classes, not methods
• Unit testing, is about testing the observable
behaviours of a class!
• Observable from the outside! Nobody cares about
the internal state of a class if it never changes the
outcome of a method call.
• Don’t test getters and setters, unless they have
custom validation

12. Three steps in test cases
• setup
• act
• verify

13. Demo
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14. Writing our first test case
public function test_execute_works_with_initialize() {
// setup
$sample = new Sample();
// act
$sample->initialize(10);
$return = $sample->execute();
// verify
$this->assertEquals(100, $return);
}

15. Testing Exception
/**
* @expectedException Exception
*/
public function test_execute_needs_initialize() {
// setup
$sample = new Sample();
// act
$sample->execute();
// verify
// that it throws and exception
}

16. Let’s add more tests
• Testing decimals
• Testing with negative values
• Testing it work with zero

17. Why use mocks?
• Isolate the test class from its dependencies.
• Test functionality that calls external services.
• Test functionality that depends on class internals.

18. Some PHPUnit Tips
• Have a fast test suite
• Use Continuous Integration
• Use Composer
• Enable code coverage in reports
• phpunit.xml.dist vs phpunit.xml
• Use specific assertions

19. Thank You
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@sudarmuthu
http://sudarmuthu.com
https://github.com/sudar