go-strict

Go Strict Standard

Rules extracted from 2 production Go services.

CRITICAL: Error Handling

GO-01: Always wrap errors with context

// BAD: no context, impossible to trace
if err != nil {
    return err
}

// GOOD: fmt.Errorf with %w for wrapping
store, err := createStore(path)
if err != nil {
    return nil, fmt.Errorf("create store: %w", err)
}

// GOOD: multiple levels of context
session, err := validateToken(token)
if err != nil {
    return fmt.Errorf("validate session for user %s: %w", userID, err)
}

GO-02: Check errors immediately, never defer

// BAD: error ignored
json.Unmarshal(data, &result)

// GOOD
if err := json.Unmarshal(data, &result); err != nil {
    return fmt.Errorf("unmarshal response: %w", err)
}

GO-03: Drain response bodies for connection reuse

resp, err := http.Get(url)
if err != nil {
    return fmt.Errorf("request failed: %w", err)
}
defer resp.Body.Close()

if resp.StatusCode != http.StatusOK {
    io.Copy(io.Discard, resp.Body) // DRAIN before closing
    return fmt.Errorf("unexpected status: %d", resp.StatusCode)
}

GO-04: Typed errors for API responses

type APIError struct {
    Status  int    `json:"status"`
    Message string `json:"message"`
    Code    string `json:"code,omitempty"`
}

func (e *APIError) Error() string {
    return fmt.Sprintf("[%d] %s", e.Status, e.Message)
}

func SendError(c *gin.Context, status int, message string) {
    c.JSON(status, APIError{Status: status, Message: message})
}

CRITICAL: Package Organization

GO-05: internal/ for private, pkg/ for reusable

project/
├── cmd/
│   └── server/
│       └── main.go              # Entry point only: no logic
├── internal/
│   ├── handlers/                # HTTP handlers (Gin)
│   ├── middleware/              # Auth, rate limit, CORS, validation
│   ├── services/                # Business logic
│   ├── models/                  # Data structures
│   ├── config/                  # Env var loading
│   └── utils/                   # Helpers
├── pkg/
│   ├── redis/                   # Reusable Redis client
│   └── sqlite/                  # Reusable SQLite wrapper
├── go.mod
└── go.sum