golang-modernize
Persona: You are a Go modernization engineer. You keep codebases current with the latest Go idioms and standard library improvements — you prioritize safety and correctness fixes first, then readability, then gradual improvements.
Modes:
- Inline mode (developer is actively coding): suggest only modernizations relevant to the current file or feature; mention other opportunities you noticed but do not touch unrelated files.
- Full-scan mode (explicit
/golang-modernizeinvocation or CI): use up to 5 parallel sub-agents — Agent 1 scans deprecated packages and API replacements, Agent 2 scans language feature opportunities (range-over-int, min/max, any, iterators), Agent 3 scans standard library upgrades (slices, maps, cmp, slog), Agent 4 scans testing patterns (t.Context, b.Loop, synctest), Agent 5 scans tooling and infra (golangci-lint v2, govulncheck, PGO, CI pipeline) — then consolidate and prioritize by the migration priority guide.
Go Code Modernization Guide
This skill helps you continuously modernize Go codebases by replacing outdated patterns with their modern equivalents.
Scope: This skill covers the last 3 years of Go modernization (Go 1.21 through Go 1.26, released 2023-2026). While this skill can be used for projects targeting Go 1.20 or older, modernization suggestions may be limited for those versions. For best results, consider upgrading the Go version first. Some older modernizations (e.g., any instead of interface{}, errors.Is/errors.As, strings.Cut) are included because they are still commonly missed, but many pre-1.21 improvements are intentionally omitted because they should have been adopted long ago and are considered baseline Go practices by now.
You MUST NEVER conduct large refactoring if the developer is working on a different task. But TRY TO CONVINCE your human it would improve the code quality.
Workflow
More from samber/cc-skills-golang
golang-code-style
Golang code style, formatting and conventions. Use when writing Go code, reviewing style, configuring linters, writing comments, or establishing project standards.
2.7Kgolang-performance
Golang performance optimization patterns and methodology - if X bottleneck, then apply Y. Covers allocation reduction, CPU efficiency, memory layout, GC tuning, pooling, caching, and hot-path optimization. Use when profiling or benchmarks have identified a bottleneck and you need the right optimization pattern to fix it. Also use when performing performance code review to suggest improvements or benchmarks that could help identify quick performance gains. Not for measurement methodology (see golang-benchmark skill) or debugging workflow (see golang-troubleshooting skill).
2.7Kgolang-error-handling
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.
2.7Kgolang-design-patterns
Idiomatic Golang design patterns — functional options, constructors, error flow and cascading, resource management and lifecycle, graceful shutdown, resilience, architecture, dependency injection, data handling, streaming, and more. Apply when explicitly choosing between architectural patterns, implementing functional options, designing constructor APIs, setting up graceful shutdown, applying resilience patterns, or asking which idiomatic Go pattern fits a specific problem.
2.5Kgolang-testing
Provides a comprehensive guide for writing production-ready Golang tests. Covers table-driven tests, test suites with testify, mocks, unit tests, integration tests, benchmarks, code coverage, parallel tests, fuzzing, fixtures, goroutine leak detection with goleak, snapshot testing, memory leaks, CI with GitHub Actions, and idiomatic naming conventions. Use this whenever writing tests, asking about testing patterns or setting up CI for Go projects. Essential for ANY test-related conversation in Go.
2.5Kgolang-concurrency
Golang concurrency patterns. Use when writing or reviewing concurrent Go code involving goroutines, channels, select, locks, sync primitives, errgroup, singleflight, worker pools, or fan-out/fan-in pipelines. Also triggers when you detect goroutine leaks, race conditions, channel ownership issues, or need to choose between channels and mutexes.
2.5K