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

Universal Conventions

Log Format Standard

All logs should follow this format for consistency:

[ClassName] methodName: description key=value

Log Levels

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