# Introducing Dejavu: Recomposition Testing for Jetpack Compose

DevFeed: [Introducing Dejavu: Recomposition Testing for Jetpack Compose](<https://devfeed.tech/articles/introducing-dejavu-recomposition-testing-for-jetpack-compose-27344.md>)

Original publisher: [Read original article](<https://blog.mmckenna.me/introducing-dejavu>)

Author: Matt McKenna

Published: 2026-03-09T19:26:54Z

Content type: release

Language: en

Sources: [Matt McKenna](<https://devfeed.tech/sources/matt-mckenna.md>)

Topics: [Jetpack Compose](<https://devfeed.tech/topics/jetpack-compose.md>), [Testing](<https://devfeed.tech/topics/testing.md>), [AI Agent](<https://devfeed.tech/topics/ai-agent.md>)

Tags: [ai-agent](<https://devfeed.tech/tags/ai-agent.md>), [android](<https://devfeed.tech/tags/android.md>), [compose](<https://devfeed.tech/tags/compose.md>), [diagnostics](<https://devfeed.tech/tags/diagnostics.md>), [error-messages](<https://devfeed.tech/tags/error-messages.md>), [jetpack](<https://devfeed.tech/tags/jetpack.md>), [jetpack-compose](<https://devfeed.tech/tags/jetpack-compose.md>), [kotlin](<https://devfeed.tech/tags/kotlin.md>), [recomposition](<https://devfeed.tech/tags/recomposition.md>), [testing](<https://devfeed.tech/tags/testing.md>), [ui](<https://devfeed.tech/tags/ui.md>)

## AI overview

The article introduces Dejavu, a testing tool for Jetpack Compose that turns recomposition behavior into test assertions. It describes asserting expected recomposition counts, receiving diagnostic information on failures, and using CompositionTracer without production-code instrumentation, a compiler plugin, bytecode manipulation, or a Gradle plugin.

## Source excerpt

Where This Idea Came From At Square, most of the app is built on Workflow. There is an internal testing framework that lets you assert exactly how many render passes are triggered for a given interact