Go Linters：提升代码质量的必备工具

# 推荐二进制安装
curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin

# 或通过 Go 安装
go install github.com/golangci/golangci-lint/cmd/golangci-lint@latest

linters:
  enable:
    - staticcheck
    - gosimple
    - govet
    - errcheck
    - gosec
    - revive
    - gocyclo
    - misspell
    - unconvert
    - unparam

linters-settings:
  errcheck:
    check-type-assertions: true
    check-blank: true
  
  govet:
    enable-all: true
  
  gocyclo:
    min-complexity: 15
  
  revive:
    severity: warning

run:
  timeout: 5m
  tests: true
  skip-dirs:
    - vendor
    - third_party

issues:
  exclude-use-default: false
  max-issues-per-linter: 0
  max-same-issues: 0

// staticcheck 捕捉这个常见错误
func processData(ctx context.Context) {
    go func() {
        // SA1012: context.Context 不应存储在结构体中
        // 或在函数返回后传递
        doWork(ctx)  
    }()
}

// staticcheck 检测低效的字符串拼接
func buildString(items []string) string {
    s := ""
    for _, item := range items {
        s += item // SA1024: 使用 strings.Builder
    }
    return s
}

staticcheck ./...
staticcheck -f stylish ./...  # 更美观的输出
staticcheck -checks SA1*,ST* ./...  # 指定类别

# 安装 goimports
go install golang.org/x/tools/cmd/goimports@latest

# 格式化所有 Go 文件
goimports -w .

# 检查而不修改
goimports -d .

// goimports 之前
import (
    "fmt"
    "github.com/pkg/errors"
    "os"
)

// goimports 之后（自动排序和组织）
import (
    "fmt"
    "os"
    
    "github.com/pkg/errors"
)

{
  "go.formatTool": "goimports",
  "[go]": {
    "editor.formatOnSave": true
  }
}

go install github.com/securego/gosec/v2/cmd/gosec@latest
gosec ./...

// G201: SQL 字符串拼接
db.Query("SELECT * FROM users WHERE name = '" + userInput + "'")

// G304: 文件路径作为污染输入
ioutil.ReadFile(userInput)

// G401: 弱密码学原语
h := md5.New()

// G101: 硬编码凭证
password := "admin123"

linters:
  enable:
    - gosec

linters-settings:
  gosec:
    excludes:
      - G204  # 审计子进程命令
    severity: high

linters-settings:
  revive:
    rules:
      - name: var-naming
        severity: warning
        arguments:
          - ["ID", "URL", "HTTP", "API", "JSON", "XML"]  # 允许的缩写
      - name: cognitive-complexity
        arguments: [15]
      - name: cyclomatic
        arguments: [10]
      - name: line-length-limit
        arguments: [120]
      - name: function-length
        arguments: [50, 0]

// errcheck 捕捉这个
file.Close()  // 错误被忽略！

// 应该是
if err := file.Close(); err != nil {
    log.Printf("关闭文件失败: %v", err)
}

{
  "gopls": {
    "analyses": {
      "unusedparams": true,
      "shadow": true,
      "nilness": true,
      "unusedwrite": true,
      "fieldalignment": true
    },
    "staticcheck": true
  }
}

name: Lint
on:
  pull_request:
  push:
    branches: [main]

jobs:
  golangci:
    name: lint
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      
      - uses: actions/setup-go@v5
        with:
          go-version: '1.22'
          cache: true
      
      - name: golangci-lint
        uses: golangci/golangci-lint-action@v4
        with:
          version: latest
          args: --timeout=5m
          # 仅在 PR 上显示新问题
          only-new-issues: true

lint:
  image: golangci/golangci-lint:latest
  stage: test
  script:
    - golangci-lint run --timeout=5m --out-format colored-line-number
  cache:
    paths:
      - .golangci.cache
  only:
    - merge_requests
    - main

docker run --rm -v $(pwd):/app -w /app golangci/golangci-lint:latest golangci-lint run -v

.PHONY: lint
lint:
	golangci-lint run --timeout=5m

.PHONY: lint-fix
lint-fix:
	golangci-lint run --fix --timeout=5m

.PHONY: format
format:
	goimports -w .
	gofmt -s -w .

.PHONY: check
check: format lint
	go test -race -coverprofile=coverage.out ./...
	go vet ./...

# 自动修复可能的
golangci-lint run --fix

# 仅修复特定 Linter
golangci-lint run --fix --disable-all --enable=goimports,gofmt

# 预览更改而不应用
golangci-lint run --fix --out-format=json | jq '.Issues[] | select(.Fixed == true)'

// ineffassign: 无效的分配
x := 5  // 从未使用
x = 10

// 修复：删除未使用的变量

// nilaway: 潜在的 nil 指针解引用
var user *User
fmt.Println(user.Name)  // 如果 user 为 nil 会崩溃

// 修复：添加 nil 检查
if user != nil {
    fmt.Println(user.Name)
}

// prealloc: 建议预分配切片
var results []string
for _, item := range items {
    results = append(results, process(item))
}

// 修复：预分配
results := make([]string, 0, len(items))

// 禁用特定 Linter
//nolint:errcheck
file.Close()

// 禁用多个 Linter 并提供原因
//nolint:gosec,G304 // 用户提供的路径在之前已验证
ioutil.ReadFile(trustedPath)

// 禁用整个文件
//nolint:stylecheck
package main

run:
  # 使用更多 CPU 核心
  concurrency: 4
  
  # 缓存分析结果
  build-cache: true
  modules-download-mode: readonly
  
  # 跳过生成的文件
  skip-files:
    - ".*\\.pb\\.go$"
    - ".*_generated\\.go$"

# GitHub Actions
- uses: actions/cache@v3
  with:
    path: ~/.cache/golangci-lint
    key: ${{ runner.os }}-golangci-lint-${{ hashFiles('**/go.sum') }}

linters:
  enable:
    - staticcheck
    - govet
    - errcheck
    - gosec
    - gosimple
    - ineffassign
    - revive
    - typecheck
    - unused
    - misspell
    - gocyclo
    - dupl
    - goconst
    - gofmt
    - goimports
    
linters-settings:
  gocyclo:
    min-complexity: 10
  errcheck:
    check-type-assertions: true
    check-blank: true
  gosec:
    severity: medium

linters:
  enable:
    - staticcheck
    - govet
    - errcheck
    - unparam
    - unconvert
    - misspell
    - gofmt
    - goimports
    - nakedret
    - gocognit

linters-settings:
  nakedret:
    max-func-lines: 30
  gocognit:
    min-complexity: 20

linters:
  enable:
    - govet
    - errcheck
    - staticcheck
    - gofmt
    - ineffassign
    
run:
  tests: false  # 为速度跳过测试 Linting

issues:
  exclude-rules:
    - path: _test\.go
      linters:
        - errcheck

go install go.uber.org/nilaway/cmd/nilaway@latest
nilaway ./...

go install github.com/segmentio/golines@latest
golines -w --max-len=120 .

go install golang.org/x/vuln/cmd/govulncheck@latest
govulncheck ./...

run:
  tests: true  # 分析测试文件
  
issues:
  exclude-rules:
    # 但在测试中允许一些灵活性
    - path: _test\.go
      linters:
        - funlen
        - gocyclo

# 预提交钩子
cat > .git/hooks/pre-commit << 'EOF'
#!/bin/sh
make lint
EOF
chmod +x .git/hooks/pre-commit