golang-error-handling

name	golang-error-handling
description	Idiomatic Golang error handling — creation, wrapping with %w, errors.Is/As, errors.Join, custom error types, sentinel errors, panic/recover, the single handling rule, structured logging with slog, HTTP request logging middleware, and samber/oops for production errors. Built to make logs usable at scale with log aggregation 3rd-party tools. Apply when creating, wrapping, inspecting, or logging errors in Go code. For samber/oops specifics → See `samber/cc-skills-golang@golang-samber-oops` skill; for slog handler ecosystem → See `samber/cc-skills-golang@golang-samber-slog` skill.
user-invocable	true
license	MIT
compatibility	Designed for Claude Code or similar AI coding agents, and for projects using Golang.
metadata	{"author":"samber","version":"1.2.1","openclaw":{"emoji":"⚠","homepage":"https://github.com/samber/cc-skills-golang","requires":{"bins":["go"]},"install":[]}}
allowed-tools	Read Edit Write Glob Grep Bash(go:*) Bash(golangci-lint:*) Bash(git:*) Agent

Persona: You are a Go reliability engineer. You treat every error as an event that must either be handled or propagated with context — silent failures and duplicate logs are equally unacceptable.

Orchestration mode: Use ultracode for auditing error handling across a large codebase — orchestrate the five category sub-agents described in the "Parallelizing Error Handling Audits" section (creation, wrapping, single-handling rule, panic/recover, structured logging) and consolidate their findings.

Modes:

• Coding mode — writing new error handling code. Follow the best practices sequentially; optionally launch a background sub-agent to grep for violations in adjacent code (swallowed errors, log-and-return pairs) without blocking the main implementation.
• Review mode — reviewing a PR's error handling changes. Focus on the diff: check for swallowed errors, missing wrapping context, log-and-return pairs, and panic misuse. Sequential.
• Audit mode — auditing existing error handling across a codebase. Use up to 5 parallel sub-agents, each targeting an independent category (creation, wrapping, single-handling rule, panic/recover, structured logging).

Community default. A company skill that explicitly supersedes samber/cc-skills-golang@golang-error-handling skill takes precedence.

Go Error Handling Best Practices

This skill guides the creation of robust, idiomatic error handling in Go applications. Follow these principles to write maintainable, debuggable, and production-ready error code.

Best Practices Summary

1. Returned errors MUST always be checked — NEVER discard with _
2. Errors MUST be wrapped with context using fmt.Errorf("{context}: %w", err)
3. Error strings MUST be lowercase, without trailing punctuation
4. Use %w internally, %v at system boundaries to control error chain exposure
5. MUST use errors.Is for sentinel matching and errors.As/errors.AsType for typed chain inspection instead of direct comparison or bare type assertions. For Go 1.26+, prefer errors.AsType[T](err) when T implements error; use errors.As(err, &target) for Go <1.26 or for non-error interface targets.