Debug Log Patterns

Overview

This skill provides copy-paste-ready logging patterns for common debugging scenarios across multiple languages. Use these patterns when instrumenting code during PDCA debug cycles.

Supported Languages

Language	File	Primary Use Case
Dart/Flutter	references/dart-flutter.md	Flutter mobile/web apps
Kotlin/Android	references/kotlin-android.md	Native Android apps
Swift/iOS	references/swift-ios.md	Native iOS apps
JavaScript/TypeScript	references/javascript-typescript.md	Web apps, Node.js, React Native

Universal Conventions

Log Format Standard

All logs should follow this format for consistency:

[ClassName] methodName: description key=value

Log Levels

Level	When to Use
DEBUG/TRACE	Detailed flow tracing, variable values
INFO	Significant events, state transitions
WARN	Unexpected but recoverable situations
ERROR	Failures that affect functionality

Common Patterns (All Languages)

Pattern: Method Entry/Exit

[ClassName] methodName: ENTER params=(param1, param2)
[ClassName] methodName: EXIT result=value

Pattern: Conditional Branch

[ClassName] methodName: condition branch=TAKEN/SKIPPED reason=why

Pattern: Loop Iteration

[ClassName] methodName: loop iteration=N/total item=current

Pattern: State Transition

[ClassName] methodName: state from=oldState to=newState trigger=event

Pattern: Async Operation

[ClassName] operationName: START
[ClassName] operationName: SUCCESS result=summary
[ClassName] operationName: ERROR error=message

Quick Selection Guide

Debugging Flutter/Dart app? -> See references/dart-flutter.md

Debugging Android native (Kotlin)? -> See references/kotlin-android.md

Debugging iOS native (Swift)? -> See references/swift-ios.md

Debugging web/Node.js/React? -> See references/javascript-typescript.md

Best Practices

1. Be specific - Include actual values, not just "value changed"
2. Be consistent - Use the same format throughout the codebase
3. Be temporary - Remove debug logs after issue is resolved
4. Be contextual - Include enough info to understand without seeing code
5. Be careful with sensitive data - Never log passwords, tokens, PII

References

• references/dart-flutter.md - Dart/Flutter logging patterns
• references/kotlin-android.md - Kotlin/Android logging patterns
• references/swift-ios.md - Swift/iOS logging patterns
• references/javascript-typescript.md - JavaScript/TypeScript logging patterns