---

name: "kotlin-code-review" description: "Review a Kotlin change for coroutine cancellation, lifecycle-aware flows, and null assertions. Use for a Kotlin code review. Do not use for a non-Kotlin repository or to swallow CancellationException."

Kotlin Code Review Skill for Copilot

Copilot skill kotlin-code-review for Kotlin. The description decides when Copilot loads it. Keep this copy under .github/skills.

When to run

Run this review for a Kotlin coroutine, a Flow, a Compose screen, or an Android lifecycle change.

When to leave it

Stop for a non-Kotlin repository. Do not upgrade Kotlin or Compose unless the user asked.

Steps

1. Read the Kotlin version in the version catalog or build.gradle. A 2.4-only API on an older compiler is a high finding.
2. Search for GlobalScope, runBlocking, and catch (e: Exception) that does not rethrow CancellationException. Each is a high finding on app code.
3. Check Flow collection. A collection that ignores the lifecycle is a finding.
4. Search for !!. Each one on external data is a finding.
5. Run the unit test task only if the user asked. Otherwise write not run. Do not claim a device run you did not do.

Output

Findings with severity, file, line, the cancellation or null bug, and a fix.

## Findings
- high | path:line | what is wrong | what to do instead

## No findings
Say "No findings" and list the files you opened. A search you skipped is not a clean result.

## Example
Input: `catch (e: Exception) { }` around a `viewModelScope.launch` body that can throw `CancellationException`.
Output: high | NotesViewModel.kt:19 | the catch swallows cancellation | rethrow `CancellationException`, then handle the other failures.

Do not flag the valid pattern named in the standards. Flag the mistake next to it.

Stop

Stop when the user asks you to swallow cancellation so a job "always finishes".

Severity

high is a bug a caller can hit or a secret that leaks. medium is a broken contract that needs a specific input. low is a cleanup that does not change behaviour.