Kotlin Code Review

This command invokes the kotlin-reviewer agent for comprehensive Kotlin-specific code review.

What This Command Does

1. Identify Kotlin Changes: Find modified .kt and .kts files via git diff
2. Run Build & Static Analysis: Execute ./gradlew build, detekt, ktlintCheck
3. Security Scan: Check for SQL injection, command injection, hardcoded secrets
4. Null Safety Review: Analyze !! usage, platform type handling, unsafe casts
5. Coroutine Review: Check structured concurrency, dispatcher usage, cancellation
6. Generate Report: Categorize issues by severity

When to Use

Use /kotlin-review when:

• After writing or modifying Kotlin code
• Before committing Kotlin changes
• Reviewing pull requests with Kotlin code
• Onboarding to a new Kotlin codebase
• Learning idiomatic Kotlin patterns

Review Categories

CRITICAL (Must Fix)

• SQL/Command injection vulnerabilities
• Force-unwrap !! without justification
• Platform type null safety violations
• GlobalScope usage (structured concurrency violation)
• Hardcoded credentials
• Unsafe deserialization

HIGH (Should Fix)

• Mutable state where immutable suffices
• Blocking calls inside coroutine context
• Missing cancellation checks in long loops
• Non-exhaustive when on sealed types
• Large functions (>50 lines)
• Deep nesting (>4 levels)

MEDIUM (Consider)

• Non-idiomatic Kotlin (Java-style patterns)
• Missing trailing commas
• Scope function misuse or nesting
• Missing sequence for large collection chains
• Redundant explicit types

Automated Checks Run

# Build check
./gradlew build

# Static analysis
./gradlew detekt

# Formatting check
./gradlew ktlintCheck

# Tests
./gradlew test

Example Usage

User: /kotlin-review

Agent:
# Kotlin Code Review Report

## Files Reviewed
- src/main/kotlin/com/example/service/UserService.kt (modified)
- src/main/kotlin/com/example/routes/UserRoutes.kt (modified)

## Static Analysis Results
✓ Build: Successful
✓ detekt: No issues
WARNING: ktlint: 2 formatting warnings

## Issues Found

[CRITICAL] Force-Unwrap Null Safety
File: src/main/kotlin/com/example/service/UserService.kt:28
Issue: Using !! on nullable repository result
```kotlin
val user = repository.findById(id)!!  // NPE risk
```
Fix: Use safe call with error handling
```kotlin
val user = repository.findById(id)
    ?: throw UserNotFoundException("User $id not found")
```

[HIGH] GlobalScope Usage
File: src/main/kotlin/com/example/routes/UserRoutes.kt:45
Issue: Using GlobalScope breaks structured concurrency
```kotlin
GlobalScope.launch {
    notificationService.sendWelcome(user)
}
```
Fix: Use the call's coroutine scope
```kotlin
launch {
    notificationService.sendWelcome(user)
}
```

## Summary
- CRITICAL: 1
- HIGH: 1
- MEDIUM: 0

Recommendation: FAIL: Block merge until CRITICAL issue is fixed

Approval Criteria

Integration with Other Commands

• Use /kotlin-test first to ensure tests pass
• Use /kotlin-build if build errors occur
• Use /kotlin-review before committing
• Use /code-review for non-Kotlin-specific concerns

Related

• Agent: agents/kotlin-reviewer.md
• Skills: skills/kotlin-patterns/, skills/kotlin-testing/