Mutation Testing - Backend Meetup @ STRV

Transcript

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   MUTATION TESTING Ruan Martinelli, Backend Developer at STRV

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   2 https://en.wikipedia.org/wiki/Category:Software_testing

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   1. REPLACE "AND" WITH "OR" 3

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   2. REPLACE "+" WITH "-" 4

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   3. CODE COVERAGE 5

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   3. CODE COVERAGE 6

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   3. CODE COVERAGE 7

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   “What if I told you there is a codebase that

   is not yours and it passes all your tests? What if told you there are 200?” 8
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   Mutations are small "faults" or "bugs" inserted into your code.

   When a mutation is applied to the code, a mutant is created. Mutation testing: 1. Change your code in small ways 2. Run the test suite once for each changed version 3. Analyze results - If one or more test breaks, it’s said that the mutant was killed - If all tests passes, it’s said that the mutant survived MUTATIONS, MUTANTS & MUTATION TESTING 9
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    4. LIST OF COMMON MUTATIONS 10

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    List of Mutation Testing tools: • Java - PIT •

    Ruby - Mutant • PHP - Infection • C# - VisualMutator & Stryker.NET • Python - MutPy • JavaScript - Stryker TOOLING 11
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    DEMO 12

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    KOA.JS 13 • Koa.js has 345 tests which take ~3s

    to run • 4 files were mutated, 793 mutants were created • Total execution time was 12m28s (8 cores)
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    KOA.JS 14

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    KOA.JS 15

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    KOA.JS 16

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    KOA.JS 17

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    KOA.JS 18

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    KOA.JS 19

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    KOA.JS 20

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    Mutation testing is resource and time-consuming • Run tests in

    the cloud periodically • Parallelism and distributed computing • Diff-based approach • AI & Machine learning • Run only on critical parts of your system GOING FURTHER 21
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    THANK YOU! Ruan Martinelli / ruan.martinelli@strv.com / @ruanmartinelli 22

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    QUESTIONS