---
description: Go style matches .golangci.yaml (funlen, lll, revive, gocritic).
globs: "**/*.go"
alwaysApply: false
---

# Go conventions

Lint source of truth is `.golangci.yaml`.

- `funlen`: 100 lines / 100 statements. Split EventLoop vs business vs worker.
- `lll`: 240 columns.
- `errcheck` / `govet` / `staticcheck` / `unused` must stay clean.
- `gocritic` performance tag is on; avoid copying large structs in range.
- `revive`: real error strings, context as first argument, no unused params.
- Format with `goimports`; local prefix `spark-server`.
- Hot path: pass `context.Context`, never `context.TODO()`.
- Domain errors live in `internal/pkg/errs` and are mapped at Transport.

```go
// BAD: EventLoop does I/O
func (s *Server) OnTraffic(c gnet.Conn) gnet.Action {
    db.Create(msg) // forbidden
    return gnet.None
}

// GOOD
func (s *Server) OnTraffic(c gnet.Conn) gnet.Action {
    _ = s.pool.Submit(ctx, func() { s.handleBusiness(frame) })
    return gnet.None
}
```