@ClareSudbery MenderCon ‘24 Use code coverage and mutation testing to add tests to legacy code 

Useful links from today Useful Links @ClareSudbery 

Untested legacy code Add tests before refactoring @ClareSudbery When would you do this? 

…because safe, confident refactoring rocks! @ClareSudbery When would you do this? 

Landing in a neat pair-synchronized way. https://www.instagram.com/p/BsY1qBeg5Qg @ClareSudbery 

Bamboo, by No Fit State 

@ClareSudbery https://www.geepawhill.org/2021/09/29/many-more-much-smaller-steps-first-sketch/ 

Demo: Using code coverage to add tests to existing code @ClareSudbery Using coverage to add tests 

Code coverage tools @ClareSudbery Using coverage to add tests 

@ClareSudbery Use coverage to find missing test data Doing the exercise yourself • Original code is here: https://github.com/emilybache/GildedRose-Refactoring-Kata • Requirements are in the readme • Run this command to clone the code: • git clone https://github.com/emilybache/GildedRose-Refactoring-Kata.git • Choose your language • My demo code is here: https://github.com/claresudbery/GildedRose-Refactoring- Kata/blob/coverage-demo-complete/csharpcore/GildedRoseTests/GildedRoseTest.cs 

Demo Using mutation testing to improve your test suite @ClareSudbery Using mutation testing to improve tests 

@ClareSudbery • Original code is here: https://github.com/emilybache/GildedRose-Refactoring-Kata • Requirements are in the readme • Run this command to clone the code: • git clone https://github.com/emilybache/GildedRose-Refactoring-Kata.git • Choose your language • My demo code is here: https://github.com/claresudbery/GildedRose-Refactoring- Kata/blob/csharp-mutation-complete/csharpcore/GildedRoseTests/GildedRoseTest.cs Use mutation testing to find missing untested edge cases Doing the exercise yourself 

Questions? @ClareSudbery Using coverage and mutation testing to add and improve tests 

Useful links from today Useful Links @ClareSudbery 

I hosted a podcast… https://www.madetech.com/podcast/ @ClareSudbery 

Relevant podcast episodes… @ClareSudbery Test Driven Development: tinyurl.com/mtb-geepaw-hill Refactoring: tinyurl.com/mtb-emily-bache Balancing Change: tinyurl.com/kevlin-henney-twitter Changing legacy systems: tinyurl.com/meri-williams- twitter 

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Sudbery Software Engineering Ltd Does your team want help to improve their software delivery? Coaching, keynotes & workshops Events and info: tinyurl.com/csudbery Mastodon: mastodon.social/@ClareSudbery LinkedIn: tinyurl.com/lin-csudbery Podcast: tinyurl.com/tech-better-pod 

Thank you!