// 破壊的変更の具体例
 
// ケース 1: 関数シグネチャの変更 → MAJOR
// Before:
function getUser(id: string): User { ... }
// After:
function getUser(id: string, options: GetUserOptions): User { ... }
// 既存の呼び出しコードが壊れる → MAJOR
 
// ケース 2: 任意パラメータの追加 → MINOR
// Before:
function getUser(id: string): User { ... }
// After:
function getUser(id: string, options?: GetUserOptions): User { ... }
// 既存の呼び出しコードは影響なし → MINOR
 
// ケース 3: レスポンス形式の変更 → MAJOR
// Before:
// { "name": "Alice", "email": "alice@example.com" }
// After:
// { "data": { "name": "Alice", "email": "alice@example.com" } }
// 既存のパーサーが壊れる → MAJOR
 
// ケース 4: レスポンスへのフィールド追加 → MINOR
// Before:
// { "name": "Alice", "email": "alice@example.com" }
// After:
// { "name": "Alice", "email": "alice@example.com", "avatar": "url" }
// 既存のパーサーは影響なし (未知のフィールドを無視する前提) → MINOR
 
// ケース 5: デフォルト値の変更 → ケースバイケース
// 動作が変わるがシグネチャは同じ → 通常 MAJOR（ユーザーの期待を裏切る場合）

# Conventional Commits のフォーマット
# <type>[optional scope]: <description>
#
# [optional body]
#
# [optional footer(s)]
 
# 例: 新機能
git commit -m "feat(auth): ソーシャルログインを追加
 
Google と GitHub による OAuth2 認証を実装。
既存のメール/パスワード認証に影響なし。
 
Closes #123"
 
# 例: バグ修正
git commit -m "fix(api): ページネーションのオフセット計算を修正
 
0始まりのインデックスが1始まりとして計算されていた問題を修正。
 
Fixes #456"
 
# 例: 破壊的変更
git commit -m "feat(api)!: レスポンス形式をJSON:API仕様に変更
 
BREAKING CHANGE: API レスポンスの構造が変更されました。
data プロパティでラップされるようになります。
移行ガイド: docs/migration-v3.md"

// commitlint.config.js に相当する設定
// package.json 内
{
  "commitlint": {
    "extends": ["@commitlint/config-conventional"],
    "rules": {
      "type-enum": [2, "always", [
        "feat", "fix", "docs", "style", "refactor",
        "perf", "test", "build", "ci", "chore", "revert"
      ]],
      "subject-max-length": [2, "always", 72],
      "body-max-line-length": [2, "always", 100]
    }
  }
}

# .github/workflows/commitlint.yml — PR のコミットメッセージを検証
name: Commitlint
 
on:
  pull_request:
    branches: [main]
 
jobs:
  commitlint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0
 
      - uses: actions/setup-node@v4
        with:
          node-version: 20
 
      - name: Install commitlint
        run: npm install --save-dev @commitlint/cli @commitlint/config-conventional
 
      - name: Validate PR commits
        run: npx commitlint --from ${{ github.event.pull_request.base.sha }} --to ${{ github.event.pull_request.head.sha }} --verbose

// package.json
{
  "scripts": {
    "prepare": "husky"
  },
  "devDependencies": {
    "@commitlint/cli": "^19.0.0",
    "@commitlint/config-conventional": "^19.0.0",
    "husky": "^9.0.0"
  }
}

# .husky/commit-msg
npx --no -- commitlint --edit ${1}

# コミットメッセージのインタラクティブ作成 (commitizen)
# インストール
npm install --save-dev commitizen cz-conventional-changelog
 
# package.json に追加
# "config": {
#   "commitizen": {
#     "path": "cz-conventional-changelog"
#   }
# }
 
# 使用
npx cz
# ? Select the type of change: feat
# ? What is the scope: auth
# ? Short description: ソーシャルログインを追加
# ? Longer description: Google と GitHub による OAuth2 認証を実装
# ? Breaking changes? No
# ? Issues closed: #123

# .github/workflows/release.yml
name: Release
 
on:
  push:
    branches: [main]
 
permissions:
  contents: write
  issues: write
  pull-requests: write
  packages: write
 
jobs:
  release:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0
          persist-credentials: false
 
      - uses: actions/setup-node@v4
        with:
          node-version: 20
          cache: npm
 
      - run: npm ci
 
      - name: Run tests
        run: npm test
 
      - name: Semantic Release
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
        run: npx semantic-release

// .releaserc.json — semantic-release 設定
{
  "branches": [
    "main",
    { "name": "next", "prerelease": true },
    { "name": "beta", "prerelease": true }
  ],
  "plugins": [
    "@semantic-release/commit-analyzer",
    "@semantic-release/release-notes-generator",
    [
      "@semantic-release/changelog",
      { "changelogFile": "CHANGELOG.md" }
    ],
    [
      "@semantic-release/npm",
      { "npmPublish": true }
    ],
    [
      "@semantic-release/github",
      {
        "assets": [
          { "path": "dist/**", "label": "Distribution" }
        ]
      }
    ],
    [
      "@semantic-release/git",
      {
        "assets": ["CHANGELOG.md", "package.json"],
        "message": "chore(release): ${nextRelease.version} [skip ci]\n\n${nextRelease.notes}"
      }
    ]
  ]
}

// .releaserc.json — カスタム commit-analyzer 設定
{
  "plugins": [
    [
      "@semantic-release/commit-analyzer",
      {
        "preset": "conventionalcommits",
        "releaseRules": [
          { "type": "feat", "release": "minor" },
          { "type": "fix", "release": "patch" },
          { "type": "perf", "release": "patch" },
          { "type": "refactor", "release": "patch" },
          { "type": "docs", "scope": "api", "release": "patch" },
          { "type": "build", "scope": "deps", "release": "patch" },
          { "breaking": true, "release": "major" }
        ],
        "parserOpts": {
          "noteKeywords": ["BREAKING CHANGE", "BREAKING CHANGES", "BREAKING"]
        }
      }
    ],
    [
      "@semantic-release/release-notes-generator",
      {
        "preset": "conventionalcommits",
        "presetConfig": {
          "types": [
            { "type": "feat", "section": "Features" },
            { "type": "fix", "section": "Bug Fixes" },
            { "type": "perf", "section": "Performance" },
            { "type": "refactor", "section": "Refactoring", "hidden": false },
            { "type": "docs", "section": "Documentation", "hidden": false },
            { "type": "chore", "hidden": true },
            { "type": "style", "hidden": true },
            { "type": "test", "hidden": true }
          ]
        }
      }
    ]
  ]
}

# .github/workflows/release-with-docker.yml
name: Release with Docker
 
on:
  push:
    branches: [main]
 
jobs:
  release:
    runs-on: ubuntu-latest
    permissions:
      contents: write
      packages: write
 
    outputs:
      new-release-published: ${{ steps.semantic.outputs.new_release_published }}
      new-release-version: ${{ steps.semantic.outputs.new_release_version }}
 
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0
          persist-credentials: false
 
      - uses: actions/setup-node@v4
        with:
          node-version: 20
          cache: npm
 
      - run: npm ci && npm test
 
      - name: Semantic Release
        id: semantic
        uses: cycjimmy/semantic-release-action@v4
        with:
          semantic_version: 23
          extra_plugins: |
            @semantic-release/changelog
            @semantic-release/git
            conventional-changelog-conventionalcommits
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
  docker:
    needs: release
    if: needs.release.outputs.new-release-published == 'true'
    runs-on: ubuntu-latest
    permissions:
      packages: write
 
    steps:
      - uses: actions/checkout@v4
 
      - name: Login to GHCR
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}
 
      - name: Build and Push
        uses: docker/build-push-action@v5
        with:
          context: .
          push: true
          tags: |
            ghcr.io/${{ github.repository }}:v${{ needs.release.outputs.new-release-version }}
            ghcr.io/${{ github.repository }}:latest

// .changeset/config.json
{
  "$schema": "https://unpkg.com/@changesets/config/schema.json",
  "changelog": "@changesets/cli/changelog",
  "commit": false,
  "fixed": [],
  "access": "public",
  "baseBranch": "main",
  "updateInternalDependencies": "patch"
}

<!-- .changeset/happy-dogs-dance.md (自動生成されるテンプレート) -->
---
"@myorg/core": minor
"@myorg/utils": patch
---
 
ユーザープロフィール API にアバター画像アップロード機能を追加。
utils パッケージに画像リサイズヘルパーを追加。

# .github/workflows/changesets.yml
name: Changesets
 
on:
  push:
    branches: [main]
 
concurrency: ${{ github.workflow }}-${{ github.ref }}
 
jobs:
  release:
    runs-on: ubuntu-latest
    permissions:
      contents: write
      pull-requests: write
      packages: write
 
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0
 
      - uses: actions/setup-node@v4
        with:
          node-version: 20
          cache: npm
 
      - run: npm ci
 
      - name: Create Release PR or Publish
        id: changesets
        uses: changesets/action@v1
        with:
          publish: npm run release
          version: npm run version
          title: 'chore: version packages'
          commit: 'chore: version packages'
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
 
      - name: Create GitHub Releases
        if: steps.changesets.outputs.published == 'true'
        run: |
          PACKAGES='${{ steps.changesets.outputs.publishedPackages }}'
          echo "$PACKAGES" | jq -r '.[] | "\(.name)@\(.version)"' | while read pkg; do
            NAME=$(echo "$pkg" | cut -d@ -f1-2)
            VERSION=$(echo "$pkg" | rev | cut -d@ -f1 | rev)
            gh release create "$NAME@v$VERSION" \
              --title "$NAME v$VERSION" \
              --generate-notes
          done
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

// .changeset/config.json — 高度な設定
{
  "$schema": "https://unpkg.com/@changesets/config/schema.json",
  "changelog": [
    "@changesets/changelog-github",
    { "repo": "myorg/myapp" }
  ],
  "commit": false,
  "fixed": [
    ["@myorg/react-components", "@myorg/react-icons"]
  ],
  "linked": [
    ["@myorg/core", "@myorg/utils", "@myorg/types"]
  ],
  "access": "public",
  "baseBranch": "main",
  "updateInternalDependencies": "patch",
  "ignore": ["@myorg/docs", "@myorg/examples"],
  "snapshot": {
    "useCalculatedVersion": true,
    "prereleaseTemplate": "{tag}-{datetime}-{commit}"
  }
}

# .github/workflows/release-please.yml
name: Release Please
 
on:
  push:
    branches: [main]
 
permissions:
  contents: write
  pull-requests: write
 
jobs:
  release-please:
    runs-on: ubuntu-latest
    outputs:
      release_created: ${{ steps.release.outputs.release_created }}
      tag_name: ${{ steps.release.outputs.tag_name }}
 
    steps:
      - uses: googleapis/release-please-action@v4
        id: release
        with:
          release-type: node
          token: ${{ secrets.GITHUB_TOKEN }}

// release-please-config.json — モノレポ対応設定
{
  "$schema": "https://raw.githubusercontent.com/googleapis/release-please/main/schemas/config.json",
  "packages": {
    "packages/core": {
      "release-type": "node",
      "component": "core",
      "changelog-path": "CHANGELOG.md"
    },
    "packages/cli": {
      "release-type": "node",
      "component": "cli",
      "changelog-path": "CHANGELOG.md"
    },
    "packages/server": {
      "release-type": "node",
      "component": "server",
      "changelog-path": "CHANGELOG.md"
    }
  },
  "plugins": [
    {
      "type": "node-workspace",
      "updateAllPackages": true
    },
    {
      "type": "linked-versions",
      "groupName": "myapp",
      "components": ["core", "cli", "server"]
    }
  ]
}

<!-- CHANGELOG.md (自動生成例) -->
# Changelog
 
## [2.1.0](https://github.com/myorg/myapp/compare/v2.0.0...v2.1.0) (2025-03-15)
 
### Features
 
* **auth:** ソーシャルログインを追加 ([#123](https://github.com/myorg/myapp/issues/123)) ([a1b2c3d](https://github.com/myorg/myapp/commit/a1b2c3d))
* **dashboard:** リアルタイム通知を実装 ([#130](https://github.com/myorg/myapp/issues/130)) ([e4f5g6h](https://github.com/myorg/myapp/commit/e4f5g6h))
 
### Bug Fixes
 
* **api:** ページネーションのオフセット計算を修正 ([#456](https://github.com/myorg/myapp/issues/456)) ([i7j8k9l](https://github.com/myorg/myapp/commit/i7j8k9l))
 
### Performance Improvements
 
* **query:** N+1 クエリを解消しレスポンス時間を 40% 改善 ([#140](https://github.com/myorg/myapp/issues/140)) ([m0n1o2p](https://github.com/myorg/myapp/commit/m0n1o2p))
 
## [2.0.0](https://github.com/myorg/myapp/compare/v1.5.0...v2.0.0) (2025-02-01)
 
### BREAKING CHANGES
 
* **api:** レスポンス形式を JSON:API 仕様に変更 ([#100](https://github.com/myorg/myapp/issues/100))

// changelog-template.js — カスタム CHANGELOG テンプレート
const changelogConfig = {
  writerOpts: {
    transform: (commit, context) => {
      // commit type の日本語マッピング
      const typeMap = {
        feat: '新機能',
        fix: 'バグ修正',
        perf: 'パフォーマンス改善',
        refactor: 'リファクタリング',
        docs: 'ドキュメント',
        build: 'ビルド',
        ci: 'CI/CD',
      };
 
      if (typeMap[commit.type]) {
        commit.type = typeMap[commit.type];
      } else {
        return null; // 表示しない
      }
 
      // scope の日本語化 (任意)
      if (commit.scope) {
        commit.scope = commit.scope.replace(/auth/g, '認証')
                                    .replace(/api/g, 'API')
                                    .replace(/ui/g, 'UI');
      }
 
      return commit;
    },
    groupBy: 'type',
    commitGroupsSort: (a, b) => {
      const order = ['新機能', 'バグ修正', 'パフォーマンス改善', 'リファクタリング'];
      return order.indexOf(a.title) - order.indexOf(b.title);
    },
  },
};
 
module.exports = changelogConfig;

// feature-flags.ts — Feature Flag の実装
interface FeatureFlag {
  name: string;
  enabled: boolean;
  rolloutPercentage?: number;
  allowedUsers?: string[];
  enabledEnvironments?: string[];
  description: string;
  createdAt: string;
  expiresAt?: string;
}
 
class FeatureFlagService {
  private flags: Map<string, FeatureFlag> = new Map();
 
  constructor(private readonly config: FeatureFlag[]) {
    for (const flag of config) {
      this.flags.set(flag.name, flag);
    }
  }
 
  isEnabled(flagName: string, context?: {
    userId?: string;
    environment?: string;
  }): boolean {
    const flag = this.flags.get(flagName);
    if (!flag) return false;
 
    // グローバルに無効
    if (!flag.enabled) return false;
 
    // 有効期限チェック
    if (flag.expiresAt && new Date(flag.expiresAt) < new Date()) {
      return false;
    }
 
    // 環境チェック
    if (flag.enabledEnvironments && context?.environment) {
      if (!flag.enabledEnvironments.includes(context.environment)) {
        return false;
      }
    }
 
    // ユーザー固有のアクセス
    if (flag.allowedUsers && context?.userId) {
      if (flag.allowedUsers.includes(context.userId)) {
        return true;
      }
    }
 
    // ロールアウト率による制御
    if (flag.rolloutPercentage !== undefined && context?.userId) {
      const hash = this.hashUserId(context.userId);
      return hash < flag.rolloutPercentage;
    }
 
    return flag.enabled;
  }
 
  private hashUserId(userId: string): number {
    let hash = 0;
    for (let i = 0; i < userId.length; i++) {
      const char = userId.charCodeAt(i);
      hash = ((hash << 5) - hash) + char;
      hash = hash & hash;
    }
    return Math.abs(hash) % 100;
  }
}
 
// 使用例
const featureFlags = new FeatureFlagService([
  {
    name: 'new-checkout-flow',
    enabled: true,
    rolloutPercentage: 10,  // 10% のユーザーに展開
    enabledEnvironments: ['production', 'staging'],
    description: '新しいチェックアウトフロー',
    createdAt: '2025-03-01',
    expiresAt: '2025-06-01',
  },
  {
    name: 'dark-mode',
    enabled: true,
    allowedUsers: ['user-001', 'user-002'],  // 特定ユーザーのみ
    description: 'ダークモード対応',
    createdAt: '2025-02-15',
  },
]);
 
// API エンドポイントでの使用
app.get('/checkout', (req, res) => {
  if (featureFlags.isEnabled('new-checkout-flow', {
    userId: req.user.id,
    environment: process.env.NODE_ENV,
  })) {
    return renderNewCheckout(req, res);
  }
  return renderLegacyCheckout(req, res);
});

# ホットフィックスの手順
 
# 1. main から hotfix ブランチを作成
git checkout main
git pull origin main
git checkout -b hotfix/fix-payment-timeout
 
# 2. 修正をコミット
git commit -m "fix(payment): タイムアウト値を30秒に延長
 
決済API のタイムアウトが10秒で、ネットワーク遅延時に
タイムアウトエラーが頻発していた問題を修正。
 
Fixes #789"
 
# 3. テスト実行
npm test
 
# 4. main にマージ (PR 経由)
gh pr create --base main --title "fix(payment): タイムアウト値を修正" --body "..."
 
# 5. semantic-release が自動で PATCH バージョンアップ
# 例: v1.2.3 → v1.2.4
 
# 6. develop ブランチにもマージ (Git Flow の場合)
git checkout develop
git merge main
git push origin develop

# .github/workflows/rollback.yml — 緊急ロールバック
name: Emergency Rollback
 
on:
  workflow_dispatch:
    inputs:
      target-version:
        description: 'Version to rollback to (e.g., v1.2.3)'
        required: true
      reason:
        description: 'Reason for rollback'
        required: true
      environment:
        description: 'Target environment'
        required: true
        type: choice
        options:
          - production
          - staging
 
jobs:
  rollback:
    runs-on: ubuntu-latest
    environment: ${{ inputs.environment }}
 
    steps:
      - uses: actions/checkout@v4
        with:
          ref: ${{ inputs.target-version }}
 
      - name: Verify target version exists
        run: |
          if ! git tag | grep -q "^${{ inputs.target-version }}$"; then
            echo "Error: Tag ${{ inputs.target-version }} not found"
            exit 1
          fi
 
      - name: Deploy rollback version
        run: |
          echo "Rolling back to ${{ inputs.target-version }}"
          echo "Reason: ${{ inputs.reason }}"
          # デプロイコマンド (環境に応じて変更)
          # aws ecs update-service ...
          # argocd app set myapp --revision ...
 
      - name: Notify rollback
        uses: slackapi/slack-github-action@v1
        with:
          payload: |
            {
              "text": "ROLLBACK executed: ${{ inputs.environment }} → ${{ inputs.target-version }}\nReason: ${{ inputs.reason }}\nBy: ${{ github.actor }}"
            }
        env:
          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
 
      - name: Create incident issue
        run: |
          gh issue create \
            --title "Rollback: ${{ inputs.environment }} → ${{ inputs.target-version }}" \
            --body "## Rollback Details
          - **Environment**: ${{ inputs.environment }}
          - **From**: latest
          - **To**: ${{ inputs.target-version }}
          - **Reason**: ${{ inputs.reason }}
          - **Executed by**: ${{ github.actor }}
          - **Time**: $(date -u '+%Y-%m-%d %H:%M:%S UTC')
 
          ## Action Items
          - [ ] Root cause analysis
          - [ ] Fix PR created
          - [ ] Post-mortem scheduled" \
            --label "incident,rollback"
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

# .github/workflows/release-gate.yml — リリース品質ゲート
name: Release Quality Gate
 
on:
  pull_request:
    branches: [main]
 
jobs:
  quality-gate:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
 
      - uses: actions/setup-node@v4
        with:
          node-version: 20
          cache: npm
 
      - run: npm ci
 
      # 1. ユニットテスト
      - name: Unit Tests
        run: npm test -- --coverage
        env:
          CI: true
 
      # 2. カバレッジチェック
      - name: Coverage Check
        run: |
          COVERAGE=$(npx c8 check-coverage --lines 80 --functions 80 --branches 70 2>&1) || {
            echo "Coverage below threshold"
            exit 1
          }
 
      # 3. リンティング
      - name: Lint
        run: npm run lint
 
      # 4. 型チェック
      - name: Type Check
        run: npx tsc --noEmit
 
      # 5. セキュリティ監査
      - name: Security Audit
        run: npm audit --audit-level=high
 
      # 6. ライセンスチェック
      - name: License Check
        run: npx license-checker --failOn "GPL-3.0;AGPL-3.0"
 
      # 7. バンドルサイズチェック
      - name: Bundle Size Check
        run: |
          npm run build
          SIZE=$(du -sb dist/ | cut -f1)
          MAX_SIZE=5242880  # 5MB
          if [ "$SIZE" -gt "$MAX_SIZE" ]; then
            echo "Bundle size ($SIZE bytes) exceeds limit ($MAX_SIZE bytes)"
            exit 1
          fi
 
      # 8. Changeset チェック (変更がある場合)
      - name: Check for changeset
        run: |
          if git diff --name-only ${{ github.event.pull_request.base.sha }} | grep -qE '\.(ts|tsx|js|jsx)$'; then
            if ! ls .changeset/*.md 2>/dev/null | grep -v README; then
              echo "Warning: Source files changed but no changeset found"
              echo "Run 'npx changeset' to add a changeset"
            fi
          fi

# 演習1: 基本実装のテンプレート
class Exercise1:
    """基本的な実装パターンの演習"""
 
    def __init__(self):
        self.data = []
 
    def validate_input(self, value):
        """入力値の検証"""
        if value is None:
            raise ValueError("入力値がNoneです")
        return True
 
    def process(self, value):
        """データ処理のメインロジック"""
        self.validate_input(value)
        self.data.append(value)
        return self.data
 
    def get_results(self):
        """処理結果の取得"""
        return {
            'count': len(self.data),
            'data': self.data
        }
 
# テスト
def test_exercise1():
    ex = Exercise1()
    assert ex.process(1) == [1]
    assert ex.process(2) == [1, 2]
    assert ex.get_results()['count'] == 2
 
    try:
        ex.process(None)
        assert False, "例外が発生するべき"
    except ValueError:
        pass
 
    print("全テスト合格!")
 
test_exercise1()

# 演習2: 応用パターン
from typing import List, Dict, Optional
from datetime import datetime
 
class AdvancedExercise:
    """応用パターンの演習"""
 
    def __init__(self, max_size: int = 100):
        self._items: List[Dict] = []
        self._max_size = max_size
        self._created_at = datetime.now()
 
    def add(self, key: str, value: any) -> bool:
        """アイテムの追加（サイズ制限付き）"""
        if len(self._items) >= self._max_size:
            return False
        self._items.append({
            'key': key,
            'value': value,
            'timestamp': datetime.now().isoformat()
        })
        return True
 
    def find(self, key: str) -> Optional[Dict]:
        """キーによる検索"""
        for item in reversed(self._items):
            if item['key'] == key:
                return item
        return None
 
    def remove(self, key: str) -> bool:
        """キーによる削除"""
        for i, item in enumerate(self._items):
            if item['key'] == key:
                self._items.pop(i)
                return True
        return False
 
    def stats(self) -> Dict:
        """統計情報"""
        return {
            'total_items': len(self._items),
            'max_size': self._max_size,
            'usage_percent': len(self._items) / self._max_size * 100,
            'uptime': str(datetime.now() - self._created_at)
        }
 
# テスト
def test_advanced():
    ex = AdvancedExercise(max_size=3)
    assert ex.add("a", 1) == True
    assert ex.add("b", 2) == True
    assert ex.add("c", 3) == True
    assert ex.add("d", 4) == False  # サイズ制限
    assert ex.find("b")['value'] == 2
    assert ex.remove("b") == True
    assert ex.find("b") is None
    stats = ex.stats()
    assert stats['total_items'] == 2
    print("応用テスト全合格!")
 
test_advanced()

# 演習3: パフォーマンス最適化
import time
from functools import lru_cache
 
# 最適化前（O(n^2)）
def slow_search(data: list, target: int) -> int:
    """非効率な検索"""
    for i in range(len(data)):
        for j in range(i + 1, len(data)):
            if data[i] + data[j] == target:
                return (i, j)
    return (-1, -1)
 
# 最適化後（O(n)）
def fast_search(data: list, target: int) -> tuple:
    """ハッシュマップを使った効率的な検索"""
    seen = {}
    for i, num in enumerate(data):
        complement = target - num
        if complement in seen:
            return (seen[complement], i)
        seen[num] = i
    return (-1, -1)
 
# ベンチマーク
def benchmark():
    import random
    data = list(range(5000))
    random.shuffle(data)
    target = data[100] + data[4000]
 
    start = time.time()
    result1 = slow_search(data, target)
    slow_time = time.time() - start
 
    start = time.time()
    result2 = fast_search(data, target)
    fast_time = time.time() - start
 
    print(f"非効率版: {slow_time:.4f}秒")
    print(f"効率版:   {fast_time:.6f}秒")
    print(f"高速化率: {slow_time/fast_time:.0f}倍")
 
benchmark()

# デバッグ用ユーティリティ
import logging
import traceback
from functools import wraps
 
# ロガーの設定
logging.basicConfig(
    level=logging.DEBUG,
    format='%(asctime)s [%(levelname)s] %(name)s: %(message)s'
)
logger = logging.getLogger(__name__)
 
def debug_decorator(func):
    """関数の入出力をログ出力するデコレータ"""
    @wraps(func)
    def wrapper(*args, **kwargs):
        logger.debug(f"呼び出し: {func.__name__}(args={args}, kwargs={kwargs})")
        try:
            result = func(*args, **kwargs)
            logger.debug(f"戻り値: {func.__name__} -> {result}")
            return result
        except Exception as e:
            logger.error(f"例外発生: {func.__name__}: {e}")
            logger.error(traceback.format_exc())
            raise
    return wrapper
 
@debug_decorator
def process_data(items):
    """データ処理（デバッグ対象）"""
    if not items:
        raise ValueError("空のデータ")
    return [item * 2 for item in items]