golang-code-style

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

Go Code Style

Style rules that require human judgment — linters handle formatting, this skill handles clarity. For naming see samber/cc-skills-golang@golang-naming skill; for design patterns see samber/cc-skills-golang@golang-design-patterns skill; for struct/interface design see samber/cc-skills-golang@golang-structs-interfaces skill.

"Clear is better than clever." — Go Proverbs

When ignoring a rule, add a comment to the code.

Line Length & Breaking

No rigid line limit, but lines beyond ~120 characters MUST be broken. Break at semantic boundaries, not arbitrary column counts. Function calls with 4+ arguments MUST use one argument per line — even when the prompt asks for single-line code:

// Good — each argument on its own line, closing paren separate
mux.HandleFunc("/api/users", func(w http.ResponseWriter, r *http.Request) {
    handleUsers(
        w,
        r,
        serviceName,
        cfg,
        logger,
        authMiddleware,
    )
})

When a function signature is too long, the real fix is often fewer parameters (use an options struct) rather than better line wrapping. For multi-line signatures, put each parameter on its own line.

Variable Declarations

SHOULD use := for non-zero values, var for zero-value initialization. The form signals intent: var means "this starts at zero."

var count int              // zero value, set later
name := "default"          // non-zero, := is appropriate
var buf bytes.Buffer       // zero value is ready to use

Slice & Map Initialization

Slices and maps MUST be initialized explicitly, never nil. Nil maps panic on write; nil slices serialize to null in JSON (vs [] for empty slices), surprising API consumers.

users := []User{}                       // always initialized
m := map[string]int{}                   // always initialized
users := make([]User, 0, len(ids))      // preallocate when capacity is known
m := make(map[string]int, len(items))   // preallocate when size is known