gcon: Skill for Claude Code

Go Code Review

Quick Reference

Issue Type	Reference
Missing error checks, wrapped errors	references/error-handling.md
Race conditions, channel misuse	references/concurrency.md
Interface pollution, naming	references/interfaces.md
Resource leaks, defer misuse	references/common-mistakes.md

Review Checklist

• All errors are checked (no _ = err)
• Errors wrapped with context (fmt.Errorf("...: %w", err))
• Resources closed with defer immediately after creation
• No goroutine leaks (channels closed, contexts canceled)
• Interfaces defined by consumers, not producers
• Interface names end in -er (Reader, Writer, Handler)
• Exported names have doc comments
• No naked returns in functions > 5 lines
• Context passed as first parameter
• Mutexes protect shared state, not methods

When to Load References

• Reviewing error return patterns → error-handling.md
• Reviewing goroutines/channels → concurrency.md
• Reviewing type definitions → interfaces.md
• General Go review → common-mistakes.md

Review Questions

1. Are all error returns checked and wrapped?
2. Are goroutines properly managed with context cancellation?
3. Are resources (files, connections) closed with defer?
4. Are interfaces minimal and defined where used?

Valid Patterns (Do NOT Flag)

These patterns are acceptable and should NOT be flagged as issues:

• _ = err with reason comment - Intentionally ignored errors with explanation

  _ = conn.Close() // Best effort cleanup, already handling primary error
  

• Empty interface interface{} - For truly generic code (pre-generics codebases)
• Naked returns in short functions - Acceptable in functions < 5 lines with named returns
• Channel without close - When consumer stops via context cancellation, not channel close
• Mutex protecting struct fields - Even if accessed only via methods, this is correct encapsulation
• //nolint directives with reason - Acceptable when accompanied by explanation

  //nolint:errcheck // Error logged but not returned per API contract
  

• Defer in loop - When function scope cleanup is intentional (e.g., processing files in batches)
• Functional options pattern - type Option func(*T) with With* constructors is idiomatic for configurable types

  func NewServer(addr string, opts ...Option) *Server { ... }
  

• sync.Pool for hot paths - Acceptable for reducing allocation pressure in performance-critical code

  var bufPool = sync.Pool{New: func() any { return new(bytes.Buffer) }}