An Introduction to Snapshot testing

1. AN INTRODUCTION TO SNAPSHOT TESTING Freek Van der Herten
2. About me Freek Van der Herten Developer at SPATIE @freekmurze freek.dev spatie.be/products ohdear.app
3. spatie.be/open-source 300+ open source packages PHP & Laravel 175 million downloads total 9 million downloads per month
4. LET’S TALK ABOUT 
 SNAPSHOT TESTING
5. What? A file on disk – let’s call it a snapshot Test succeeds if the output matches the snapshot If not, the test will fail
6. Where does it come from? Characterisation testing Popularized by Facebook Jest Testing interfaces
7. How can we do it in PHP? github.com/spatie/phpunit-snapshot-assertions github.com/spatie/pest-plugin-snapshots assertMatchesSnapshot assertMatchesJsonSnapshot assertMatchesXmlSnapshot
8. DEMO
9. WRAPPING UP
10. Advantages Very easy to get started with Can be used to validate complex output Easily update all the tests in one go
11. Disadvantages Brittle Hard to pinpoint exact point of failure Bugs can be easily written in the snapshots
12. Interesting links github.com/spatie/phpunit-snapshot-assertions github.com/spatie/pest-plugin-snapshots github.com/spatie/shiki-php github.com/spatie/laravel-markdown torchlight.dev
13. ONE MORE THING
14. testing-laravel.com Premium video course, 6+ hours of video Learn how to tests a Laravel app from scratch Tips and tricks to sharpen your skills Two courses in one: Pest & PHPUnit 10 % discount with SPATIE-LOVES-LARACON
15. Thank you! spatie.be spatie.be/products spatie.be/open-source testing-laravel.com freek.dev