mcpField
G
go

go

github.com/miles990开发2657 次安装41 周前更新
代码仓库

关于 go

面向 Go 开发者的编程技能资料，介绍惯用 Go 编码方式，并通过示例涵盖并发、错误处理、上下文、泛型与测试。

主要功能

  1. 01结构体、方法与接口
  2. 02错误处理模式
  3. 03Goroutine、通道与工作池
  4. 04Context 超时控制
  5. 05泛型与测试示例

适用场景

  1. 01设计 Repository 接口
  2. 02处理 Go 服务中的错误
  3. 03使用工作池运行并发任务
  4. 04测试 Go 函数

安装

复制下面的命令，在终端中运行。

$npx skills add https://github.com/miles990/claude-software-skills --skill go

安装后在 Claude Code 中输入/go确认已加载。

包含的文件

除 SKILL.md 外，安装时一起下载的参考资料和脚本。

templates/
go.mod
Makefile
README.md

详细介绍

Go

概述

Go 编程模式，包括并发、错误处理和地道的 Go 代码。

基础模式

结构体与方法
package main

import (
	"encoding/json"
	"fmt"
	"time"
)

// Struct definition
type User struct {
	ID        string    `json:"id"`
	Email     string    `json:"email"`
	Name      string    `json:"name"`
	CreatedAt time.Time `json:"created_at"`
	metadata  map[string]interface{} // unexported (private)
}

// Constructor function
func NewUser(email, name string) *User {
	return &User{
		ID:        generateID(),
		Email:     email,
		Name:      name,
		CreatedAt: time.Now(),
		metadata:  make(map[string]interface{}),
	}
}

// Value receiver (for read-only)
func (u User) FullName() string {
	return u.Name
}

// Pointer receiver (for mutations or large structs)
func (u *User) SetMetadata(key string, value interface{}) {
	u.metadata[key] = value
}

// Embedding (composition)
type Admin struct {
	User        // Embedded struct
	Permissions []string
}

func (a *Admin) HasPermission(perm string) bool {
	for _, p := range a.Permissions {
		if p == perm {
			return true
		}
	}
	return false
}
接口
// Interface definition
type Repository interface {
	Find(id string) (*User, error)
	FindAll() ([]*User, error)
	Create(user *User) error
	Update(user *User) error
	Delete(id string) error
}

// Interface implementation (implicit)
type MemoryRepository struct {
	users map[string]*User
}

func NewMemoryRepository() *MemoryRepository {
	return &MemoryRepository{
		users: make(map[string]*User),
	}
}

func (r *MemoryRepository) Find(id string) (*User, error) {
	user, ok := r.users[id]
	if !ok {
		return nil, ErrNotFound
	}
	return user, nil
}

func (r *MemoryRepository) Create(user *User) error {
	r.users[user.ID] = user
	return nil
}

// Compile-time interface check
var _ Repository = (*MemoryRepository)(nil)

// Empty interface (any type)
func PrintAny(v interface{}) {
	fmt.Printf("%v\n", v)
}

// Type assertion
func ProcessValue(v interface{}) {
	switch val := v.(type) {
	case string:
		fmt.Println("String:", val)
	case int:
		fmt.Println("Int:", val)
	case *User:
		fmt.Println("User:", val.Name)
	default:
		fmt.Println("Unknown type")
	}
}

错误处理

import (
	"errors"
	"fmt"
)

// Sentinel errors
var (
	ErrNotFound   = errors.New("not found")
	ErrBadRequest = errors.New("bad request")
)

// Custom error type
type ValidationError struct {
	Field   string
	Message string
}

func (e *ValidationError) Error() string {
	return fmt.Sprintf("validation error on %s: %s", e.Field, e.Message)
}

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

// Error checking
func ProcessUser(id string) error {
	user, err := GetUser(id)
	if err != nil {
		if errors.Is(err, ErrNotFound) {
			return fmt.Errorf("user not found: %s", id)
		}
		var validationErr *ValidationError
		if errors.As(err, &validationErr) {
			return fmt.Errorf("validation failed: %s", validationErr.Field)
		}
		return err
	}
	// Process user...
	return nil
}

// Multi-error handling
type MultiError struct {
	Errors []error
}

func (m *MultiError) Error() string {
	var msgs []string
	for _, err := range m.Errors {
		msgs = append(msgs, err.Error())
	}
	return strings.Join(msgs, "; ")
}

func (m *MultiError) Add(err error) {
	if err != nil {
		m.Errors = append(m.Errors, err)
	}
}

func (m *MultiError) HasErrors() bool {
	return len(m.Errors) > 0
}

并发

Goroutine 与 Channel
// Basic goroutine
func main() {
	go func() {
		fmt.Println("Hello from goroutine")
	}()

	time.Sleep(100 * time.Millisecond)
}

// Channel basics
func worker(jobs <-chan int, results chan<- int) {
	for job := range jobs {
		results <- job * 2
	}
}

func main() {
	jobs := make(chan int, 100)
	results := make(chan int, 100)

	// Start workers
	for w := 0; w < 3; w++ {
		go worker(jobs, results)
	}

	// Send jobs
	for j := 0; j < 9; j++ {
		jobs <- j
	}
	close(jobs)

	// Collect results
	for r := 0; r < 9; r++ {
		fmt.Println(<-results)
	}
}

// Select for multiple channels
func main() {
	ch1 := make(chan string)
	ch2 := make(chan string)

	go func() {
		time.Sleep(100 * time.Millisecond)
		ch1 <- "one"
	}()

	go func() {
		time.Sleep(200 * time.Millisecond)
		ch2 <- "two"
	}()

	for i := 0; i < 2; i++ {
		select {
		case msg1 := <-ch1:
			fmt.Println("Received:", msg1)
		case msg2 := <-ch2:
			fmt.Println("Received:", msg2)
		case <-time.After(500 * time.Millisecond):
			fmt.Println("Timeout")
		}
	}
}
并发模式
import (
	"context"
	"sync"
)

// Worker pool
type WorkerPool struct {
	numWorkers int
	jobs       chan func()
	wg         sync.WaitGroup
}

func NewWorkerPool(numWorkers int) *WorkerPool {
	pool := &WorkerPool{
		numWorkers: numWorkers,
		jobs:       make(chan func(), numWorkers*2),
	}
	pool.Start()
	return pool
}

func (p *WorkerPool) Start() {
	for i := 0; i < p.numWorkers; i++ {
		go func() {
			for job := range p.jobs {
				job()
				p.wg.Done()
			}
		}()
	}
}

func (p *WorkerPool) Submit(job func()) {
	p.wg.Add(1)
	p.jobs <- job
}

func (p *WorkerPool) Wait() {
	p.wg.Wait()
}

func (p *WorkerPool) Close() {
	close(p.jobs)
}

// Fan-out, fan-in
func FanOut(ctx context.Context, input <-chan int, workers int) []<-chan int {
	outputs := make([]<-chan int, workers)
	for i := 0; i < workers; i++ {
		outputs[i] = worker(ctx, input)
	}
	return outputs
}

func FanIn(ctx context.Context, channels ...<-chan int) <-chan int {
	var wg sync.WaitGroup
	merged := make(chan int)

	output := func(c <-chan int) {
		defer wg.Done()
		for v := range c {
			select {
			case merged <- v:
			case <-ctx.Done():
				return
			}
		}
	}

	wg.Add(len(channels))
	for _, c := range channels {
		go output(c)
	}

	go func() {
		wg.Wait()
		close(merged)
	}()

	return merged
}

// Rate limiter
type RateLimiter struct {
	ticker *time.Ticker
	tokens chan struct{}
}

func NewRateLimiter(rate int, burst int) *RateLimiter {
	rl := &RateLimiter{
		ticker: time.NewTicker(time.Second / time.Duration(rate)),
		tokens: make(chan struct{}, burst),
	}

	// Fill initial burst
	for i := 0; i < burst; i++ {
		rl.tokens <- struct{}{}
	}

	// Refill tokens
	go func() {
		for range rl.ticker.C {
			select {
			case rl.tokens <- struct{}{}:
			default:
			}
		}
	}()

	return rl
}

func (rl *RateLimiter) Wait(ctx context.Context) error {
	select {
	case <-rl.tokens:
		return nil
	case <-ctx.Done():
		return ctx.Err()
	}
}

Context

import (
	"context"
	"time"
)

// Context with timeout
func FetchWithTimeout(url string) ([]byte, error) {
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
	if err != nil {
		return nil, err
	}

	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	return io.ReadAll(resp.Body)
}

// Context with values
type contextKey string

const userIDKey contextKey = "userID"

func WithUserID(ctx context.Context, userID string) context.Context {
	return context.WithValue(ctx, userIDKey, userID)
}

func GetUserID(ctx context.Context) (string, bool) {
	userID, ok := ctx.Value(userIDKey).(string)
	return userID, ok
}

// Passing context through layers
func Handler(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()
	ctx = WithUserID(ctx, r.Header.Get("X-User-ID"))

	result, err := ProcessRequest(ctx)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	json.NewEncoder(w).Encode(result)
}

func ProcessRequest(ctx context.Context) (*Result, error) {
	// Check for cancellation
	select {
	case <-ctx.Done():
		return nil, ctx.Err()
	default:
	}

	userID, ok := GetUserID(ctx)
	if !ok {
		return nil, errors.New("user ID not found in context")
	}

	return fetchData(ctx, userID)
}

泛型（Go 1.18+）

// Generic function
func Map[T, U any](items []T, fn func(T) U) []U {
	result := make([]U, len(items))
	for i, item := range items {
		result[i] = fn(item)
	}
	return result
}

func Filter[T any](items []T, predicate func(T) bool) []T {
	var result []T
	for _, item := range items {
		if predicate(item) {
			result = append(result, item)
		}
	}
	return result
}

func Reduce[T, U any](items []T, initial U, fn func(U, T) U) U {
	result := initial
	for _, item := range items {
		result = fn(result, item)
	}
	return result
}

// Generic type constraint
type Number interface {
	~int | ~int32 | ~int64 | ~float32 | ~float64
}

func Sum[T Number](items []T) T {
	var sum T
	for _, item := range items {
		sum += item
	}
	return sum
}

// Generic struct
type Stack[T any] struct {
	items []T
}

func (s *Stack[T]) Push(item T) {
	s.items = append(s.items, item)
}

func (s *Stack[T]) Pop() (T, bool) {
	if len(s.items) == 0 {
		var zero T
		return zero, false
	}
	item := s.items[len(s.items)-1]
	s.items = s.items[:len(s.items)-1]
	return item, true
}

// Usage
stack := &Stack[int]{}
stack.Push(1)
stack.Push(2)
val, ok := stack.Pop() // val = 2, ok = true

测试

import (
	"testing"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

// Basic test
func TestSum(t *testing.T) {
	result := Sum([]int{1, 2, 3})
	if result != 6 {
		t.Errorf("expected 6, got %d", result)
	}
}

// Table-driven tests
func TestSumTableDriven(t *testing.T) {
	tests := []struct {
		name     string
		input    []int
		expected int
	}{
		{"empty", []int{}, 0},
		{"single", []int{5}, 5},
		{"multiple", []int{1, 2, 3}, 6},
		{"negative", []int{-1, 1}, 0},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			result := Sum(tt.input)
			assert.Equal(t, tt.expected, result)
		})
	}
}

// Test with testify
func TestUser(t *testing.T) {
	user := NewUser("[email protected]", "Test User")

	require.NotNil(t, user)
	assert.Equal(t, "[email protected]", user.Email)
	assert.Equal(t, "Test User", user.Name)
	assert.NotEmpty(t, user.ID)
}

// Benchmark
func BenchmarkSum(b *testing.B) {
	items := make([]int, 1000)
	for i := range items {
		items[i] = i
	}

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		Sum(items)
	}
}

相关技能

  • [[backend]] - Go Web 服务
  • [[cloud-platforms]] - 云原生 Go
  • [[system-design]] - 系统架构

评论

支持 Markdown