軽量爆速のHono vs 高機能のNestJS！どっちを選ぶべき？

# パッケージサイズ比較
npm info hono dist.unpackedSize
# → 約30KB

npm info @nestjs/core dist.unpackedSize  
# → 約1.2MB（コアのみ）

import { Hono } from 'hono'

const app = new Hono()

// 型推論が効く
app.get('/users/:id', (c) => {
  const id = c.req.param('id') // string型
  return c.json({ id, name: 'John' })
})

// Hono版 TODO API
import { Hono } from 'hono'
import { cors } from 'hono/cors'
import { logger } from 'hono/logger'

type Todo = {
  id: number
  title: string
  completed: boolean
}

const app = new Hono()

// ミドルウェア
app.use('*', cors())
app.use('*', logger())

// インメモリストレージ（簡単のため）
let todos: Todo[] = [
  { id: 1, title: 'Learn Hono', completed: false }
]

// 全件取得
app.get('/todos', (c) => {
  return c.json(todos)
})

// 作成
app.post('/todos', async (c) => {
  const { title } = await c.req.json()
  
  if (!title) {
    return c.json({ error: 'Title is required' }, 400)
  }

  const newTodo: Todo = {
    id: Date.now(),
    title,
    completed: false
  }
  
  todos.push(newTodo)
  return c.json(newTodo, 201)
})

// 更新
app.put('/todos/:id', async (c) => {
  const id = parseInt(c.req.param('id'))
  const { title, completed } = await c.req.json()
  
  const todo = todos.find(t => t.id === id)
  if (!todo) {
    return c.json({ error: 'Todo not found' }, 404)
  }
  
  if (title !== undefined) todo.title = title
  if (completed !== undefined) todo.completed = completed
  
  return c.json(todo)
})

// 削除
app.delete('/todos/:id', (c) => {
  const id = parseInt(c.req.param('id'))
  const index = todos.findIndex(t => t.id === id)
  
  if (index === -1) {
    return c.json({ error: 'Todo not found' }, 404)
  }
  
  todos.splice(index, 1)
  return c.json({ message: 'Todo deleted' })
})

export default app

// NestJS版 TODO API

// todo.entity.ts
export class Todo {
  id: number
  title: string
  completed: boolean
}

// create-todo.dto.ts
import { IsNotEmpty, IsString } from 'class-validator'

export class CreateTodoDto {
  @IsNotEmpty()
  @IsString()
  title: string
}

// update-todo.dto.ts
import { IsOptional, IsString, IsBoolean } from 'class-validator'

export class UpdateTodoDto {
  @IsOptional()
  @IsString()
  title?: string

  @IsOptional()
  @IsBoolean()
  completed?: boolean
}

// todo.service.ts
import { Injectable, NotFoundException } from '@nestjs/common'
import { Todo } from './todo.entity'
import { CreateTodoDto } from './dto/create-todo.dto'
import { UpdateTodoDto } from './dto/update-todo.dto'

@Injectable()
export class TodoService {
  private todos: Todo[] = [
    { id: 1, title: 'Learn NestJS', completed: false }
  ]

  findAll(): Todo[] {
    return this.todos
  }

  create(createTodoDto: CreateTodoDto): Todo {
    const newTodo: Todo = {
      id: Date.now(),
      title: createTodoDto.title,
      completed: false
    }
    
    this.todos.push(newTodo)
    return newTodo
  }

  update(id: number, updateTodoDto: UpdateTodoDto): Todo {
    const todo = this.todos.find(t => t.id === id)
    if (!todo) {
      throw new NotFoundException('Todo not found')
    }

    Object.assign(todo, updateTodoDto)
    return todo
  }

  remove(id: number): void {
    const index = this.todos.findIndex(t => t.id === id)
    if (index === -1) {
      throw new NotFoundException('Todo not found')
    }
    
    this.todos.splice(index, 1)
  }
}

// todo.controller.ts
import {
  Controller,
  Get,
  Post,
  Put,
  Delete,
  Body,
  Param,
  ParseIntPipe
} from '@nestjs/common'
import { TodoService } from './todo.service'
import { CreateTodoDto } from './dto/create-todo.dto'
import { UpdateTodoDto } from './dto/update-todo.dto'

@Controller('todos')
export class TodoController {
  constructor(private readonly todoService: TodoService) {}

  @Get()
  findAll() {
    return this.todoService.findAll()
  }

  @Post()
  create(@Body() createTodoDto: CreateTodoDto) {
    return this.todoService.create(createTodoDto)
  }

  @Put(':id')
  update(
    @Param('id', ParseIntPipe) id: number,
    @Body() updateTodoDto: UpdateTodoDto
  ) {
    return this.todoService.update(id, updateTodoDto)
  }

  @Delete(':id')
  remove(@Param('id', ParseIntPipe) id: number) {
    this.todoService.remove(id)
    return { message: 'Todo deleted' }
  }
}

// app.module.ts
import { Module } from '@nestjs/common'
import { TodoController } from './todo.controller'
import { TodoService } from './todo.service'

@Module({
  controllers: [TodoController],
  providers: [TodoService],
})
export class AppModule {}

# 負荷テスト実行
wrk -t12 -c400 -d30s http://localhost:3000/todos

# Hono結果
Requests/sec: 45,230
Latency: 8.85ms average
Memory usage: ~15MB

# NestJS結果  
Requests/sec: 12,840
Latency: 31.12ms average
Memory usage: ~85MB

// wrangler.toml
name = "hono-api"
main = "src/index.ts"
compatibility_date = "2023-12-01"

[vars]
ENVIRONMENT = "production"

// src/index.ts
import { Hono } from 'hono'
import { cors } from 'hono/cors'

const app = new Hono()

app.use('*', cors())

app.get('/api/health', (c) => {
  return c.json({ 
    status: 'ok', 
    timestamp: Date.now(),
    environment: c.env.ENVIRONMENT 
  })
})

app.get('/api/edge-location', (c) => {
  const country = c.req.header('CF-IPCountry') || 'unknown'
  const colo = c.req.header('CF-RAY')?.split('-')[1] || 'unknown'
  
  return c.json({
    country,
    datacenter: colo,
    message: `Request handled at ${colo} datacenter`
  })
})

export default app

// マイクロサービス構成例
// メインアプリ: NestJS (http://main-api:3000)
// 高速API: Hono (http://fast-api:3001)

// Hono側（高頻度アクセスのエンドポイント）
import { Hono } from 'hono'

const app = new Hono()

// キャッシュ付き軽量API
app.get('/api/v1/stats/:userId', async (c) => {
  const userId = c.req.param('userId')
  
  // Redis等からキャッシュ取得
  const stats = await getStatsFromCache(userId)
  
  return c.json(stats)
})

// NestJS側（複雑な処理）
@Controller('api/v1/users')
export class UserController {
  // ユーザー作成等の複雑な処理
  @Post()
  async createUser(@Body() dto: CreateUserDto) {
    // 複雑なバリデーション・DB処理
    return this.userService.create(dto)
  }
}