Pure Reducers in Kotlin: Why Your Android Unit Tests Should Run in 5 Milliseconds

📰 Dev.to · Ouday khaled

Learn how to write pure reducers in Kotlin for fast Android unit tests

intermediate Published 21 Apr 2026
Action Steps
  1. Write pure reducer functions in Kotlin
  2. Remove dispatcher setup from unit tests
  3. Avoid using MockK for reducer tests
  4. Use Kotlin's built-in testing features for reducer tests
  5. Measure test execution time to ensure it's under 5 milliseconds
Who Needs to Know This

Android developers and testers can benefit from this approach to improve test efficiency and reduce setup time

Key Insight

💡 Pure reducers can significantly improve unit test performance by reducing setup time and dependencies

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🚀 Speed up your Android unit tests with pure reducers in Kotlin! 💡
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