Diagnosing Compose Stability

# Diagnosing Compose Stability — Read the Compiler Reports First

Compose skips recomposition by comparing parameters. When a parameter is unstable, skipping is disabled — this skill tells Claude how to find out which parameters are unstable and why. The output is a prioritized list of unstable types and non-skippable composables; the fix lives in `../stabilizing-compose-types/SKILL.md`.

## When to use this skill

- The developer asks "why does this recompose?", reports jank, dropped frames, or scroll stutter.
- A `@TraceRecomposition` log shows recomposition counts that exceed the number of meaningful state changes.
- The developer mentions Compose Compiler Reports, `classes.txt`, `composables.txt`, `composables.csv`, `module.json`, or "non-skippable".
- The developer asks how to find unstable parameters, or whether `List<Foo>`, `LocalDateTime`, or a domain type is stable.
- A reviewer asks for evidence that a perf-sensitive composable is skippable.

## When NOT to use this skill

- The unstable types are already known — jump straight to `../stabilizing-compose-types/SKILL.md`.
- The symptom is a wrong-phase state read (`Modifier.alpha(state.value)`); use `../../recomposition/deferring-state-reads/SKILL.md`.
- The symptom is a `derivedStateOf` misuse; use `../../recomposition/choosing-derivedstateof/SKILL.md`.
- The developer wants CI gating instead of one-shot diagnosis; use `../enforcing-stability-in-ci/SKILL.md`.

## Prerequisites

- Kotlin **2.0.0+** with the Compose Compiler Gradle plugin applied: `id("org.jetbrains.kotlin.plugin.compose")`. The pre-2.0 `kotlinCompilerExtensionVersion` flow is obsolete.
- A buildable **release** variant of the target module. Reports MUST be produced in release; debug adds Live Literals which makes constants look dynamic and skews every report.
- Apply the `org.jetbrains.kotlin.plugin.compose` Gradle plugin (Kotlin 2.0+). The `composeCompiler { … }` extension is owned by that plugin; AGP version is incidental.
- Optional but **PREFERRED:** the developer has a stability baseline goal, not a 100-percent-skippable goal (skydoves hot take #1 — skippability is a diagnostic, not a KPI).

## Workflow

- [ ] **1. Enable the reports in the module's `build.gradle.kts`.** Scope to release only — debug builds emit misleading data.

```kotlin
// app/build.gradle.kts (or any compose module)
plugins {
    id("com.android.application")
    id("org.jetbrains.kotlin.android")
    id("org.jetbrains.kotlin.plugin.compose")
}

composeCompiler {
    // Only emit reports for release to avoid Live Literals noise.
    val isReleaseBuild = providers.gradleProperty("composeCompilerReports").orNull == "true"
    if (isReleaseBuild) {
        reportsDestination = layout.buildDirectory.dir("compose_compiler")
        metricsDestination = layout.buildDirectory.dir("compose_compiler")
    }
}
```

Or the always-on form: