Getting the most of PHPUnit assertions

Do you know, when you are writing a test, something isn't going right and you get a failure message "Failed asserting that false is true"? Let's see how we can improve our test's assertion in other to get more helpful errors by using dedicated PHPUnit assertions. We're going to see how we can make our suite of tests stricter, avoiding PHP's false-positives weakness. Also, we'll be seeing how PHPUnit works under the hood, from the assertion method to the verification itself.

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1. Getting the most of PhPUnit assertions by Gabriel Caruso PHPers Summit 2019
7. Who am I? • Backend Developer at Usabilla • PHP Core Member • Community(ies) member • OSS contributor • Refactor/Stickers/ELEPHANTS lover
8. Assertions Test Framework way to check if a result of something matches an expectation.
9. What is an Assertion in PHPUnit?
10. self::assertEquals($expected, $actual);
11. Should I use self:: or $this->?
13. self::assertEquals($expected, $actual); Assertion What you expect to be returned What was actually returned
14. self::assertTrue($actual);
15. self::assertTrue($actual); Assertion The value we are checking
16. But, what does happen inside PHPunit to judge these assertions?
19. self::assertEquals() PHPUnit's Magic?
20. Let's take a look at some PHPunit Internals Code
21. Recap What does happen under the hood to PHPUnit judge assertEquals? $expected == $actual
22. I want to implement a assertIsCountable assertion How would you do that?
24. What if we use PHPUnit's ABI for that?
25. Let's Code ‍
26. Who does use PHPunit's ABI to write custom assertions?
27. PHP Frameworks Database, HTTP, Cache, etc. - Symfony: HTTP Assertions - Laravel: Database Assertions
28. Do we just have assertEquals and assertTrue as assertions?
29. PHPUnit has 100+ assertions Booleans, comparisons, files, XML, jSON, etc.
30. How do I know if I am using the best assertion for each test?
31. $this->assertTrue($expected == $actual); Failed asserting that false is true.
32. $this->assertTrue($expected == $actual); Assertion What you expect to be returned What was actually returned Assertion
33. self::assertEquals($expected, $actual); Failed asserting that $actual matches expected $expected.
34. $this->assertFalse(in_array(‘foo’, $array); Failed asserting that true is false.
35. $this->assertFalse(in_array(‘foo’, $array)); Assertion Assertion
36. $this->assertNotContains(‘foo’, $array); Failed asserting that an array does not contains ‘foo’.
37. How can I ensure that my project always uses the best assertion?
38. Tools that you can use to automate these refactorings - FriendsOfPHP/PHP-CS-F ixer - rectorphp/rector
39. @carusogabriel Questionings? Thank you ♡