Go Error Handling Skill

This skill provides guidelines for implementing robust error handling in Go applications. Apply these practices when writing, reviewing, or refactoring Go code that involves error creation, propagation, or handling.

When to Use This Skill

Use this skill when:

• Creating new functions or methods that return errors
• Implementing repository or service layers that interact with databases or external services
• Building gRPC or HTTP handlers that need to translate errors to status codes
• Reviewing code for proper error handling patterns
• Debugging error propagation issues

Core Principles

Error Handling Decision Flowchart

Error Occurs
    │
    ▼
Is it from an external dependency (DB, API, etc)?
    │
    ├── YES → Map to domain error + wrap with %w
    │
    └── NO → Is it a business rule violation?
              │
              ├── YES → Return appropriate domain error
              │
              └── NO → Wrap and propagate with context

At Handler Layer:
    │
    ▼
Log full error, return safe message to client

References