hono/README.md

Hono

Hono[炎] - means flame🔥 in Japanese - is small, simple, and ultrafast web flamework for a Service Workers API based serverless such as Cloudflare Workers and Fastly Compute@Edge.

import { Hono } from 'hono'
const app = new Hono()

app.get('/', (c) => c.text('Hono!!'))

app.fire()

Features

• Ultra Fast - the router is implemented with Trie-Tree structure.
• Zero dependencies - using only Web standard API.
• Middleware - builtin middleware, and you can make your own middleware.
• Optimized - for Cloudflare Workers.

Benchmark

Hono is fastest compared to other routers for Cloudflare Workers.

hono x 748,188 ops/sec ±5.40% (77 runs sampled)
itty-router x 158,817 ops/sec ±3.62% (87 runs sampled)
sunder x 332,339 ops/sec ±1.11% (95 runs sampled)
worktop x 205,906 ops/sec ±4.43% (83 runs sampled)
Fastest is hono
✨  Done in 52.79s.

Hono in 1 minute

Below is a demonstration to create an application of Cloudflare Workers with Hono.

Install

You can install from npm registry:

yarn add hono

or

npm install hono

Methods

Instance of Hono has these methods:

• app.HTTP_METHOD(path, handler)
• app.all(path, handler)
• app.route(path)
• app.use(path, middleware)
• app.fire()
• app.fetch(request, env, event)

Routing

Basic

app.HTTP_METHOD

// HTTP Methods
app.get('/', () => new Response('GET /'))
app.post('/', () => new Response('POST /'))

// Wildcard
app.get('/wild/*/card', () => {
  return new Response('GET /wild/*/card')
})

app.all

// Any HTTP methods
app.all('/hello', () => new Response('ALL Method /hello'))

Named Parameter

app.get('/user/:name', (c) => {
  const name = c.req.params('name')
  ...
})

Regexp

app.get('/post/:date{[0-9]+}/:title{[a-z]+}', (c) => {
  const date = c.req.params('date')
  const title = c.req.params('title')
  ...

Chained Route

app
  .route('/api/book')
    .get(() => {...})
    .post(() => {...})
    .put(() => {...})

async/await

app.get('/fetch-url', async () => {
  const response = await fetch('https://example.com/')
  return new Response(`Status is ${response.status}`)
})

Middleware

Builtin Middleware

import { Hono, Middleware } from 'hono'

...

app.use('*', Middleware.poweredBy())
app.use('*', Middleware.logger())
app.use(
  '/auth/*',
  Middleware.basicAuth({
    username: 'hono',
    password: 'acoolproject',
  })
)

Available builtin middleware are listed on src/middleware.

Custom Middleware

You can write your own middleware:

// Custom logger
app.use('*', async (c, next) => {
  console.log(`[${c.req.method}] ${c.req.url}`)
  await next()
})

// Add a custom header
app.use('/message/*', async (c, next) => {
  await next()
  await c.res.headers.add('x-message', 'This is middleware!')
})

app.get('/message/hello', () => 'Hello Middleware!')

Custom 404 Response

You can customize 404 Not Found response:

app.use('*', async (c, next) => {
  await next()
  if (c.res.status === 404) {
    c.res = new Response('Custom 404 Not Found', { status: 404 })
  }
})

Complex Pattern

You can also do this:

// Output response time
app.use('*', async (c, next) => {
  await next()
  const responseTime = await c.res.headers.get('X-Response-Time')
  console.log(`X-Response-Time: ${responseTime}`)
})

// Add X-Response-Time header
app.use('*', async (c, next) => {
  const start = Date.now()
  await next()
  const ms = Date.now() - start
  await c.res.headers.append('X-Response-Time', `${ms}ms`)
})

Context

To handle Request and Reponse easily, you can use Context object:

c.req

// Get Request object
app.get('/hello', (c) => {
  const userAgent = c.req.headers.get('User-Agent')
  ...
})

// Query params
app.get('/search', (c) => {
  const query = c.req.query('q')
  ...
})

// Captured params
app.get('/entry/:id', (c) => {
  const id = c.req.params('id')
  ...
})

c.res

// Response object
app.use('/', (c, next) => {
  next()
  c.res.headers.append('X-Debug', 'Debug message')
})

c.event

// FetchEvent objest
app.use('*', async (c, next) => {
  c.event.waitUntil(
    ...
  )
  await next()
})

c.env

// Environment object for Cloudflare Workers
app.get('*', async c => {
  const counter = c.env.COUNTER
  ...
})

c.text()

Render text as Content-Type:text/plain:

app.get('/say', (c) => {
  return c.text('Hello!')
})

c.json()

Render JSON as Content-Type:application/json:

app.get('/api', (c) => {
  return c.json({ message: 'Hello!' })
})

c.html()

Render HTML as Content-Type:text/html:

app.get('/', (c) => {
  return c.html('<h1>Hello! Hono!</h1>')
})

c.redirect()

Redirect, default status code is 302:

app.get('/redirect', (c) => c.redirect('/'))
app.get('/redirect-permanently', (c) => c.redirect('/', 301))

fire

app.fire() do:

addEventListener('fetch', (event) => {
  event.respondWith(this.handleEvent(event))
})

fetch

app.fetch() is for Cloudflare Module Worker syntax.

export default {
  fetch(request: Request, env: Env, event: FetchEvent) {
    return app.fetch(request, env, event)
  },
}

Cloudflare Workers with Hono

Using wrangler or miniflare, you can develop the application locally and publish it with few commands.

Let's write your first code for Cloudflare Workers with Hono.

1. Install Wrangler

Install Cloudflare Command Line "Wrangler"

npm i @cloudflare/wrangler -g

2. npm init

Make npm skeleton directory.

mkdir hono-example
cd hono-example
npm init -y

3. wrangler init

Init as a wrangler project.

wrangler init

4. npm install hono

Install hono from npm registry.

npm i hono

5. Write your app

Only 4 lines!!

import { Hono } from 'hono'
const app = new Hono()

app.get('/', (c) => c.text('Hello! Hono!'))

app.fire()

6. Run

Run the development server locally. Then, access like http://127.0.0.1:8787/ in your Web browser.

wrangler dev

Publish

Deploy to Cloudflare. That's all!

wrangler publish

Related projects

Implementation of the router is inspired by goblin. API design is inspired by express and koa. itty-router, Sunder, and worktop are the other routers or frameworks for Cloudflare Workers.

• express https://github.com/expressjs/express
• koa https://github.com/koajs/koa
• itty-router https://github.com/kwhitley/itty-router
• Sunder https://github.com/SunderJS/sunder
• goblin https://github.com/bmf-san/goblin
• worktop https://github.com/lukeed/worktop

Contributing

Contributions Welcome! You can contribute by the following way:

• Write or fix documents
• Write code of middleware
• Fix bugs
• Refactor the code
• etc.

If you can, let's make Hono together!

Author

Yusuke Wada https://github.com/yusukebe

License

Distributed under the MIT License. See LICENSE for more information.