snapshot testing (phplimburg)

Transcript

1. A practical intro to
   snapshot testing
   and PHPUnit-watcher
   

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2. About me
   Freek Van der Herten
   Partner & developer at SPATIE
   Blogging at https://murze.be
   https://murze.be/newsletter
   

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3. OPEN SOURCE SOFTWARE
   

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4. https://spatie.be/en/opensource/laravel
   

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5. Open source software
   ± 160 public repositories on GitHub
   August 2016: ± 800 000 downloads
   August 2017: ± 5 000 000 downloads
   ± 500 000 downloads a month
   

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6. LET’S TALK SNAPSHOT TESTING
   

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7. A file on disk, let’s call in snapshot
   Test succeeds if output matches snapshot
   If not, test will fail
   What?
   

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8. Another name: characterization testing
   Popularized by Facebook
   Jest
   Testing interfaces
   Where does it come from?
   

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9. https://github.com/spatie/phpunit-snapshot-assertions
   assertMatchesSnapshot
   assertMatchesJsonSnapshot
   assertMatchesXmlSnapshot
   How can we do it in PHP?
   

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10. DEMO
    

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11. WRAPPING UP
    

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12. Advantages
    Very easy to get started with
    Can be used to validate complex output
    Easily update all the tests in one go
    

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13. Disadvantages
    Brittle
    Hard to pinpoint exact point of failure
    Bugs can be easily written in the snapshots
    

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14. 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

    

    https://github.com/spatie/phpunit-watcher
    Interesting links
    

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15. Thank you!
    https://speakerdeck.com/freekmurze/snapshot-testing-phplimburg
    https://spatie.be/opensource
    https://murze.be
    https://murze.be/newsletter/
    

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16. QUESTIONS?
    

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