go✓ تایید شده

محتوای SKILL.md

---
name: go
description: Write Go code following best practices. Use when developing Go applications. Covers error handling, concurrency, and project structure.
allowed-tools: Read, Write, Edit, Bash, Glob, Grep
---

# Go Development

## Project Structure

```
myproject/
├── cmd/
│   └── server/
│       └── main.go
├── internal/
│   ├── handler/
│   ├── service/
│   └── repository/
├── pkg/
│   └── shared/
├── go.mod
└── go.sum
```

## Error Handling

```go
// Custom error types
type NotFoundError struct {
    Resource string
    ID       string
}

func (e *NotFoundError) Error() string {
    return fmt.Sprintf("%s not found: %s", e.Resource, e.ID)
}

// Error wrapping
func GetUser(id string) (*User, error) {
    user, err := db.FindUser(id)
    if err != nil {
        return nil, fmt.Errorf("GetUser(%s): %w", id, err)
    }
    return user, nil
}

// Error checking
if errors.Is(err, sql.ErrNoRows) {
    return nil, &NotFoundError{Resource: "user", ID: id}
}
```

## Concurrency

```go
// Goroutines with errgroup
func fetchAll(ctx context.Context, urls []string) ([]Response, error) {
    g, ctx := errgroup.WithContext(ctx)
    results := make([]Response, len(urls))

    for i, url := range urls {
        i, url := i, url // capture loop variables
        g.Go(func() error {
            resp, err := fetch(ctx, url)
            if err != nil {
                return err
            }
            results[i] = resp
            return nil
        })
    }

    if err := g.Wait(); err != nil {
        return nil, err
    }
    return results, nil
}

// Channels
func producer(ch chan<- int) {
    for i := 0; i < 10; i++ {
        ch <- i
    }
    close(ch)
}

func consumer(ch <-chan int) {
    for v := range ch {
        fmt.Println(v)
    }
}
```

## HTTP Handler

```go
func (h *Handler) GetUser(w http.ResponseWriter, r *http.Request) {
    ctx := r.Context()
    id := chi.URLParam(r, "id")

    user, err := h.service.GetUser(ctx, id)
    if err != nil {
        var notFound *NotFoundError
        if errors.As(err, &notFound) {
            http.Error(w, err.Error(), http.StatusNotFound)
            return
        }
        http.Error(w, "Internal error", http.StatusInternalServerError)
        return
    }

    w.Header().Set("Content-Type", "application/json")
    json.NewEncoder(w).Encode(user)
}
```

## Testing

```go
func TestGetUser(t *testing.T) {
    t.Parallel()

    tests := []struct {
        name    string
        id      string
        want    *User
        wantErr bool
    }{
        {
            name: "existing user",
            id:   "123",
            want: &User{ID: "123", Email: "[email protected]"},
        },
        {
            name:    "non-existent user",
            id:      "999",
            wantErr: true,
        },
    }

    for _, tt := range tests {
        t.Run(tt.name, func(t *testing.T) {
            got, err := service.GetUser(context.Background(), tt.id)
            if (err != nil) != tt.wantErr {
                t.Errorf("error = %v, wantErr %v", err, tt.wantErr)
            }
            if !reflect.DeepEqual(got, tt.want) {
                t.Errorf("got = %v, want %v", got, tt.want)
            }
        })
    }
}
```

## Tooling

```bash
# Format
gofmt -w .
goimports -w .

# Lint
golangci-lint run

# Test
go test -v -race -cover ./...
```

مجوز

مجوز اعلام‌شده: MIT

MIT License

Copyright (c) 2025 majiayu000

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

مشاهدهٔ مجوز در مخزن منبع — نسخهٔ منتشرشده در آن‌جا مرجع است.