jangrui
@jangrui
Public Skills
golang-pkg-go-dev
by jangrui
"Golang package and module lookup via godig, a pkg.go.dev API client (CLI + MCP server). Use for any Go/Golang library's documentation, API signatures, symbols, usage examples, which versions exist, licenses, whether a dependency has CVEs, or who imports a package — prefer this over Context7 for any Go package or module. Read-only, no auth. Not for upgrading dependencies (→ See samber/cc-skills-golang@golang-dependency-management skill), choosing a library (→ See samber/cc-skills-golang@golang-popular-libraries skill), or local symbols and an already-used dependency's resolved source, call sites, and generic instantiations (→ See samber/cc-skills-golang@golang-gopls skill)."
golang-popular-libraries
by jangrui
"Golang library and framework selection — vetted production-ready options by category (web, database, testing, logging, messaging), new and experimental stdlib packages, standard-library-first tradeoffs, and maturity signals (maintenance, license, importer counts). Apply when the user asks for library suggestions, wants to compare alternatives, needs to choose a library for a specific task, or when a new dependency is being added to the project. Not for a specific library's API once chosen (→ See that library's dedicated skill, e.g. samber/cc-skills-golang@golang-samber-lo), nor for go.mod mechanics, upgrades, or vulnerability audits (→ See samber/cc-skills-golang@golang-dependency-management skill)."
golang-security
by jangrui
"Security best practices and vulnerability prevention for Golang — injection (SQL, command, XSS), cryptography, path traversal, SSRF and HTTP security headers, cookies, secrets management, memory safety, PII in logs, STRIDE/DREAD threat modeling, plus gosec SAST, race detection, and fuzz testing. Apply when writing, reviewing, or auditing Go code for security, or when touching crypto, file or network I/O, secrets, user input, or authentication. Not for non-exploitable defensive bugs such as nil panics or slice aliasing (→ See samber/cc-skills-golang@golang-safety skill), dependency vulnerability scanning with govulncheck (→ See samber/cc-skills-golang@golang-dependency-management skill), or wiring security scanners into CI pipelines (→ See samber/cc-skills-golang@golang-continuous-integration skill)."
golang-grpc
by jangrui
"Provides gRPC usage guidelines, protobuf organization, and production-ready patterns for Golang microservices. Use when implementing, reviewing, or debugging gRPC servers/clients, writing proto files, setting up interceptors, handling gRPC errors with status codes, configuring TLS/mTLS, testing with bufconn, or working with streaming RPCs."
golang-dependency-management
by jangrui
"Dependency management for Golang projects — go.mod and go.sum, go get install and upgrade flows, Minimal Version Selection, conflict resolution with replace/exclude/retract, govulncheck scanning of the module tree, outdated dependency and binary size auditing, vendoring, tool directives, and go.work workspaces. Use when adding, removing, or upgrading Go dependencies, deciding whether to take on a package, resolving version conflicts, or auditing what a module pulls in. Covers choosing and upgrading dependency versions, not the surrounding tooling: do NOT use for fixing an exploitable vulnerability in code (→ See samber/cc-skills-golang@golang-security skill) or for wiring Dependabot/Renovate update bots into CI workflows (→ See samber/cc-skills-golang@golang-continuous-integration skill)."
golang-spf13-cobra
by jangrui
"Golang CLI command tree library using spf13/cobra — cobra.Command, RunE vs Run, PersistentPreRunE hook chain, Args validators (NoArgs, ExactArgs, MatchAll, custom), persistent vs local flags, command groups, ValidArgsFunction, RegisterFlagCompletionFunc, ShellCompDirective, usage/help template customization, man-page and markdown doc generation, and testing with SetArgs/SetOut/SetErr. Apply when using or adopting spf13/cobra, or when the codebase imports github.com/spf13/cobra. For configuration layering alongside cobra, see the samber/cc-skills-golang@golang-spf13-viper skill. For general CLI architecture (project layout, exit codes, signal handling, I/O patterns), see samber/cc-skills-golang@golang-cli."
golang-spf13-viper
by jangrui
"Golang configuration library using spf13/viper — layered precedence (flag > env > file > KV > default), BindPFlag/BindPFlags, SetEnvPrefix + SetEnvKeyReplacer + AutomaticEnv, ReadInConfig + ConfigFileNotFoundError, Unmarshal + mapstructure struct tags, Sub for sub-trees, WatchConfig + OnConfigChange for hot reload, viper.New() for test isolation, and remote KV integration. Apply when using or adopting spf13/viper, or when the codebase imports github.com/spf13/viper. For CLI command structure alongside viper, see the samber/cc-skills-golang@golang-spf13-cobra skill. For general CLI architecture, see samber/cc-skills-golang@golang-cli."
golang-safety
by jangrui
"Defensive Golang coding against accidental bugs — nil panics, typed-nil interfaces, append backing-array aliasing, silent int64-to-int32 truncation, float == comparison, defer inside loops, defensive copies of slices and maps, and usable zero values. Use when a Go program panics on a nil map write or nil pointer dereference, when reviewing code for nil-safety, numeric conversion overflow, or resource lifecycle, or when designing a type whose zero value must be safe. Not for designing concurrent access with goroutines, channels, or sync primitives (→ See samber/cc-skills-golang@golang-concurrency skill), not for exploitable vulnerabilities such as injection, weak crypto, or leaked secrets (→ See samber/cc-skills-golang@golang-security skill), and not for debugging an already-failing program (→ See samber/cc-skills-golang@golang-troubleshooting skill)."
golang-modernize
by jangrui
"Modernize Golang code to use recent language features, standard library improvements, and idiomatic patterns. Use when reviewing Go code with old-style patterns, when encountering a deprecation warning, or when the user asks for modernization, a Go version upgrade (e.g. to Go 1.27), or a CI/tooling refresh. Not for structural refactors, extracting functions, or moving code between packages (→ See samber/cc-skills-golang@golang-refactoring skill)."
golang-stretchr-testify
by jangrui
"Comprehensive guide to stretchr/testify for Golang testing. Covers assert, require, mock, and suite packages in depth. Use when writing tests with testify, creating mocks, setting up test suites, or choosing between assert and require. Covers testify assertions, mock expectations, argument matchers, call verification, suite lifecycle, and advanced patterns like Eventually, JSONEq, and custom matchers. Apply when the codebase imports github.com/stretchr/testify."
golang-documentation
by jangrui
"Comprehensive documentation guide for Golang projects, covering godoc comments, README, CONTRIBUTING, CHANGELOG, Go Playground, Example tests, API docs, and llms.txt. Use when writing or reviewing doc comments, documentation, adding code examples, setting up doc sites, or discussing documentation best practices. Triggers for both libraries and applications/CLIs."
golang-samber-do
by jangrui
"Dependency injection in Golang using samber/do — service containers, lifecycle management, scopes, health checks, graceful shutdown, and module organization. Apply when using or adopting samber/do, when the codebase imports github.com/samber/do or github.com/samber/do/v2, or when refactoring manual constructor injection into a DI container."
golang-concurrency
by jangrui
"Golang concurrency design — goroutine lifecycle and leak prevention, channels and select, channel ownership and direction, sync.Mutex/RWMutex/sync.Map/sync.Once/atomics, errgroup, singleflight, worker pools, and fan-out/fan-in pipelines. Use when writing or reviewing concurrent Go code, when choosing between channels and mutexes, when protecting a shared map or counter, or when a goroutine has no clear exit. Not for defensive coding unrelated to concurrency such as nil panics, slice aliasing, or numeric overflow (→ See samber/cc-skills-golang@golang-safety skill), and not for debugging a specific hung, crashing, or racing program after the fact (→ See samber/cc-skills-golang@golang-troubleshooting skill)."
golang-uber-fx
by jangrui
"Golang application framework using uber-go/fx — fx.New, fx.Provide, fx.Invoke, fx.Module, fx.Lifecycle hooks, fx.Annotate (name/group/As), fx.Decorate, fx.Supply, fx.Replace, fx.WithLogger, and signal-aware Run(). Apply when using or adopting uber-go/fx, when the codebase imports go.uber.org/fx, or when wiring services with fx.New. For raw DI without lifecycle, see samber/cc-skills-golang@golang-uber-dig skill."
golang-benchmark
by jangrui
"Golang benchmarking, profiling, and performance measurement. Use when writing, running, or comparing Go benchmarks, profiling hot paths with pprof, interpreting CPU/memory/trace profiles, analyzing results with benchstat, setting up CI benchmark regression detection, or investigating production performance with Prometheus runtime metrics. Also use when the developer needs deep analysis on a specific performance indicator - this skill provides the measurement methodology, while samber/cc-skills-golang@golang-performance provides the optimization patterns."
golang-samber-oops
by jangrui
"Structured error handling in Golang with samber/oops — error builders, stack traces, error codes, error context, error wrapping, error attributes, user-facing vs developer messages, panic recovery, and logger integration. Apply when using or adopting samber/oops, or when the codebase already imports github.com/samber/oops."
golang-troubleshooting
by jangrui
"Troubleshoot Golang programs systematically - find and fix the root cause. Use when encountering bugs, crashes, deadlocks, races, or unexpected behavior in Go code. Covers debugging methodology, common Go pitfalls, test-driven debugging, pprof setup and capture, Delve, race detection, GODEBUG tracing, and production debugging. Start here for any 'something is wrong' situation. Not for interpreting profiles or benchmarking (→ See samber/cc-skills-golang@golang-benchmark skill), applying optimization patterns (→ See samber/cc-skills-golang@golang-performance skill), or designing new code (→ See samber/cc-skills-golang@golang-safety skill for defensive coding, samber/cc-skills-golang@golang-concurrency skill for concurrency design)."
golang-refactoring
by jangrui
"Golang refactoring — safe, at-scale restructuring of existing Go code: a coverage-adaptive safety net, behavior-preserving transforms (gopls Rename/Extract, gofmt -r, gopatch), the Fowler catalog mapped to Go, breaking import cycles, and small stacked PRs. Apply when a function or type has grown too large, a code smell blocks a feature, or the user asks to refactor Go code — also for renaming at scale, extracting functions or interfaces, moving code between packages, or planning a multi-step refactor. Target styles owned elsewhere → See samber/cc-skills-golang@golang-naming (renames), samber/cc-skills-golang@golang-project-layout (splits), samber/cc-skills-golang@golang-modernize (idioms), samber/cc-skills-golang@golang-code-style (control flow), samber/cc-skills-golang@golang-design-patterns (patterns/DI)."
golang-stay-updated
by jangrui
"Golang ecosystem watch list — official sources (go.dev/blog, pkg.go.dev, tour.golang.org, golang-nuts), newsletters (Golang Weekly, Awesome Go Newsletter), communities (r/golang, gophers.slack.com, Go Forum, go.dev/wiki), blogs (Dave Cheney, Ardan Labs, Rob Pike), YouTube channels (Gopher Academy, GopherCon EU/UK), conferences, and Go contributors to follow on GitHub, X and Bluesky. Use when seeking Golang learning resources, discovering new libraries or tools, finding community channels or meetups, picking Go people to follow, or keeping up with Go language changes and releases. Not for querying a specific module's versions, docs, or vulnerabilities from the CLI (→ See samber/cc-skills-golang@golang-pkg-go-dev skill)."
golang-error-handling
by jangrui
"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."
golang-naming
by jangrui
"Go (Golang) naming conventions — covers packages, constructors, structs, interfaces, constants, enums, errors, booleans, receivers, getters/setters, functional options, acronyms, test functions, and subtest names. Use this skill when writing new Go code, reviewing or refactoring, choosing between naming alternatives (New vs NewTypeName, isConnected vs connected, ErrNotFound vs NotFoundError, StatusReady vs StatusUnknown at iota 0), debating Go package names (utils/helpers anti-patterns), or asking about Go naming best practices. Also trigger when the user mentions MixedCaps vs snake_case, ALL_CAPS constants, Get-prefix on getters, or error string casing. Do NOT use for general Go implementation questions that don't involve naming decisions."
golang-dependency-injection
by jangrui
"Comprehensive guide for dependency injection (DI) in Golang. Covers why DI matters (testability, loose coupling, separation of concerns, lifecycle management), manual constructor injection, and DI library comparison (google/wire, uber-go/dig, uber-go/fx, samber/do). Use this skill when designing service architecture, setting up dependency injection, refactoring tightly coupled code, managing singletons or service factories, or when the user asks about inversion of control, service containers, or wiring dependencies in Go. For a specific DI library, → See samber/cc-skills-golang@golang-google-wire, samber/cc-skills-golang@golang-uber-dig, samber/cc-skills-golang@golang-uber-fx, or samber/cc-skills-golang@golang-samber-do skills."
golang-design-patterns
by jangrui
"Idiomatic Golang design patterns — functional options, constructor APIs, init() and global-state avoidance, enums, panic vs error decisions, resource management and lifecycle, graceful shutdown, timeouts and retries, streaming and iterators, and architecture styles (clean, hexagonal, DDD, flat). Apply when 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. Not for wiring a DI container or comparing DI libraries (→ See samber/cc-skills-golang@golang-dependency-injection skill), nor for error wrapping, errors.Is/As, or logging mechanics (→ See samber/cc-skills-golang@golang-error-handling skill)."
golang-lint
by jangrui
"Linting best practices and golangci-lint configuration for Golang projects — running linters, configuring .golangci.yml, suppressing warnings with nolint directives, interpreting lint output, and selecting linters. Use when configuring golangci-lint, asking about lint warnings or nolint suppressions, setting up code quality tooling, or choosing linters. Also use when the user mentions golangci-lint, go vet, staticcheck, or revive. Not for wiring a lint step into a GitHub Actions pipeline (→ See samber/cc-skills-golang@golang-continuous-integration skill)."