Snapshot testing (dpc)

1. A practical intro to snapshot testing
2. About me Freek Van der Herten Partner & developer at SPATIE @freekmurze https://murze.be
3. About me phpantwerp.be Dries Vints @driesvints Frederick Vanbrabant @TheEdonian
4. Since 2003 Websites, applications and webshops Team 4 developers, 1 manager Specialization Laravel development
5. OPEN SOURCE SOFTWARE
6. ± 120 packages on Packagist Laravel, Framework agnostic PHP ± 4 000 000 downloads in total, growing ±450 000 a month We create a lot of it Open source software
7. http://github-awards.com/users?type=world&language=php Open source software
8. LET’S TALK SNAPSHOT TESTING
9. A file on disk, let’s call in snapshot Test succeeds if output matches snapshot If not, test will fail What?
10. Old name: characterization testing Popularized by Facebook Jest Testing interfaces Where does it come from?
11. https://github.com/spatie/phpunit-snapshot-assertions assertMatchesSnapshot assertMatchesJsonSnapshot assertMatchesXmlSnapshot How can we do it in PHP?
12. DEMO
13. WRAPPING UP
14. Advantages Very easy to get started with Can be used to validate complex output Easily update all the tests in one go
15. Disadvantages Brittle Hard to pinpoint exact point of failure Bugs can be easily written in the snapshots
16. https://github.com/spatie/phpunit-snapshot-assertions https://sebastiandedeyne.com/posts/2017/a-package-for-snapshot- testing-in-phpunit https://murze.be/2017/04/practical-introduction-snapshot-testing/ https://www.sitepoint.com/snapshot-testing-viable-php/ https://facebook.github.io/jest/docs/snapshot-testing.html Interesting links
17. QUESTIONS?
18. Thank you! https://speakerdeck.com/freekmurze/snapshot-testing-dpc https://spatie.be/opensource https://murze.be https://murze.be/newsletter/