Upgrade to Pro — share decks privately, control downloads, hide ads and more …
Sign up for free

Property-based testing: The lazy programmer's g...

Sponsored · Ship Features Fearlessly Turn features on and off without deploys. Used by thousands of Ruby developers. →
Avatar for Pierre GOUDJO Pierre GOUDJO
January 20, 2022
Programming
130
0

Property-based testing: The lazy programmer's guide to writing thousands of tests

Avatar for Pierre GOUDJO

Pierre GOUDJO

January 20, 2022

More Decks by Pierre GOUDJO

See All by Pierre GOUDJO
Simplicity matters
Avatar for Pierre GOUDJO pierregoudjo
0
83
Always available workspaces: Dotfiles, Github and other shenanigans
Avatar for Pierre GOUDJO pierregoudjo
0
67
Amazon Virtual Private Cloud
Avatar for Pierre GOUDJO pierregoudjo
0
91
Service Discovery: Fundamentals
Avatar for Pierre GOUDJO pierregoudjo
0
89
Relational Databases on AWS: Amazon RDS and Aurora
Avatar for Pierre GOUDJO pierregoudjo
0
110
Object storage: An exploration of AWS S3
Avatar for Pierre GOUDJO pierregoudjo
0
81
Load Balancing: A strategy for scalable internet applications
Avatar for Pierre GOUDJO pierregoudjo
0
100
Boring Technologies
Avatar for Pierre GOUDJO pierregoudjo
0
66
CDN: Caching and edge computing on AWS
Avatar for Pierre GOUDJO pierregoudjo
0
73

Other Decks in Programming

See All in Programming
AI駆動開発にグラフDBを重ねてみた
Avatar for Satoshi Kaneyasu satoshi256kbyte
2
790
From 6 People Classroom Meetup to 100 People Regional Conference / FOSS4G Hiroshima 2026
Avatar for YFurukawa furukawayasuto
0
190
ゲームコントローラやキーボードのファームウェアをSwiftで書く
Avatar for Kishikawa Katsumi kishikawakatsumi
1
230
iOSDC2026登壇資料.pdf
Avatar for RioFujimon riofujimon
0
150
【高い買い物LT会】初任給で話題の国産フィジカルAIを買った話
Avatar for 赤神青空 akagami
PRO
0
150
AI × TiDD / 2026.09.05 Redmine 大阪
Avatar for tokudiro tokudiro
1
150
AIエージェント時代のコードレビューを設計する
Avatar for nogu nogu66
6
2.7k
新人はどこまで自力でやり、どこからAIに頼るべきか／エンジニア育成に向き合う_先輩たちの悩みと知見共有会
Avatar for TOPPAN ict toppan_digital_dev
1
620
一人だけ、Kiroが静止する日
Avatar for Hideyuki Nagata hideg
0
100
XHTMLが残したもの
Avatar for Yosuke Furukawa yosuke_furukawa
PRO
2
780
The Past, Present, and Future of Enterprise Java
Avatar for ivargrimstad ivargrimstad
0
340
モバイル交通系ICへのチャージ実例から考える、クロスプラットフォーム開発におけるiOS実機テスト設計とCI運用
Avatar for Yu Sugawara yusuga
1
450

Featured

See All Featured
Fight the Zombie Pattern Library - RWD Summit 2016
Avatar for Marcelo Somers marcelosomers
234
17k
Designing Experiences People Love
Avatar for Jonathan Moore moore
143
24k
Context Engineering - Making Every Token Count
Avatar for Addy Osmani addyosmani
9
1.1k
How to Align SEO within the Product Triangle To Get 
Buy-In & Support - #RIMC
Avatar for Aleyda Solis aleyda
2
1.8k
Believing is Seeing
Avatar for Spiro Bolos oripsolob
1
220
職位にかかわらず全員がリーダーシップを発揮するチーム作り / Building a team where everyone can demonstrate leadership regardless of position
Avatar for MADOX madoxten
69
65k
How to Grow Your eCommerce with AI & Automation
Avatar for Katarina Dahlin katarinadahlin
PRO
1
270
The MySQL Ecosystem @ GitHub 2015
Avatar for Sam Lambert samlambert
251
13k
Claude Code のすすめ
Avatar for schroneko schroneko
67
230k
Unlocking the hidden potential of vector embeddings in international SEO
Avatar for Frank van Dijk frankvandijk
0
930
The Hidden Cost of Media on the Web [PixelPalooza 2025]
Avatar for Tammy Everts tammyeverts
2
500
Art, The Web, and Tiny UX
Avatar for Lynn Fisher lynnandtonic
304
22k

Transcript

  1. Pierre Goudjo Property-based testing The lazy programmer's guide to writing

    thousands of tests

  2. “Real-life” Scenario

  3. None
  4. None
  5. None
  6. None
  7. None
  8. None
  9. None
  10. None
  11. None
  12. None
  13. None
  14. None
  15. None
  16. None
  17. None
  18. None
  19. None
  20. None
  21. None
  22. None
  23. None
  24. None
  25. None

  26. Solution

  27. What’s an addition?

  28. None
  29. None

  30. Properties Addition • Associativity: x+(y+z) = (x+y)+z • Commutativity: x

    + y = y + x • Identity Element: x+0 = x

  31. This is property-based testing

  32. for any (x, y, …) such as precondition(x, y, …)

    holds property(x, y, …) is true

  33. Let’s implement this!!!!

  34. Is it useful?

  35. Avg • for any number (a and b ) •

    such a <= b • a <= avg(a, b) and avg(a, b) <= b • for any number (a and b ) • such a <= b • avg(a, b) == avg(a, b)

  36. Zip/Unzip • for any string (x) • such as x

    not “” • unzip(zip(x)) == x is true