template-go-web/.context/skills/go-patterns.md

Skill: Go project patterns

New endpoint checklist

1. Define request/response types in types.go
2. Write handler in handlers.go using http.HandlerFunc
3. Add route in routes.go
4. Write table-driven test in handlers_test.go
5. Run task check before committing

Error handling pattern

if err != nil {
    return fmt.Errorf("descriptiveOperation: %w", err)
}

Never log and return — do one or the other.

HTMX response pattern

func (h *Handler) ListItems(w http.ResponseWriter, r *http.Request) {
    items, err := h.store.List(r.Context())
    if err != nil {
        http.Error(w, "failed to list items", http.StatusInternalServerError)
        return
    }
    if r.Header.Get("HX-Request") == "true" {
        h.templates.Render(w, "items/_list", items)
        return
    }
    h.templates.Render(w, "items/index", items)
}

Dependency policy

• Prefer stdlib: net/http, encoding/json, database/sql
• Allowed without justification: testify, slog, templ, sqlc
• Needs justification in commit message: anything else