Hono[炎]

English · 日本語

Hono[炎] - means flame🔥 in Japanese - is small, simple, and ultrafast web framework for Cloudflare Workers and Fastly Compute@Edge.

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

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

app.fire()

Features

• Ultrafast - the router does not use linear loops.
• Zero-dependencies - using only Service Worker and Web standard API.
• Middleware - built-in middleware and ability to extend with your own middleware.
• Optimized - for Cloudflare Workers.

Benchmark

Hono is fastest, compared to other routers for Cloudflare Workers.

hono x 809,503 ops/sec ±6.94% (73 runs sampled)
itty-router x 157,310 ops/sec ±4.31% (87 runs sampled)
sunder x 328,350 ops/sec ±2.30% (95 runs sampled)
worktop x 209,758 ops/sec ±4.28% (83 runs sampled)
Fastest is hono
✨  Done in 60.66s.

Hono in 1 minute

A demonstration to create an application for Cloudflare Workers with Hono.

Now, the named path parameter has types.

Install

You can install Hono from the npm registry.

$ yarn add hono

or

$ npm install hono

Methods

An instance of Hono has these methods.

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

Routing

Basic

// HTTP Methods
app.get('/', (c) => c.text('GET /'))
app.post('/', (c) => c.text('POST /'))

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

// Any HTTP methods
app.all('/hello', (c) => c.text('Any Method /hello'))

Named Parameter

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

Regexp

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

Nested route

const book = app.route('/book')
book.get('/', (c) => c.text('List Books')) // GET /book
book.get('/:id', (c) => {
  // GET /book/:id
  const id = c.req.param('id')
  return c.text('Get Book: ' + id)
})
book.post('/', (c) => c.text('Create Book')) // POST /book

no strict

If strict is set false, /helloand/hello/ are treated the same.

const app = new Hono({ strict: false }) // Default is true

app.get('/hello', (c) => c.text('/hello or /hello/'))

async/await

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

Middleware

Built-in Middleware

Hono has built-in middleware.

import { Hono } from 'hono'
import { poweredBy } from 'hono/powered-by'
import { logger } from 'hono/logger'
import { basicAuth } from 'hono/basicAuth'

const app = new Hono()

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

Available built-in middleware is 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()
  c.header('x-message', 'This is middleware!')
})

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

Not Found

app.notFound for customizing Not Found Response.

app.notFound((c) => {
  return c.text('Custom 404 Message', 404)
})

Error Handling

app.onError handle the error and return the customized Response.

app.onError((err, c) => {
  console.error(`${err}`)
  return c.text('Custom Error Message', 500)
})

Context

To handle Request and Reponse, you can use Context object.

c.req

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

// Shortcut to get a header value
app.get('/shortcut', (c) => {
  const userAgent = c.req.header('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.param('id')
  ...
})

Shortcuts for Response

app.get('/welcome', (c) => {
  // Set headers
  c.header('X-Message', 'Hello!')
  c.header('Content-Type', 'text/plain')
  // Set HTTP status code
  c.status(201)
  // Return the response body
  return c.body('Thank you for comming')
})

The Response is the same as below.

new Response('Thank you for comming', {
  status: 201,
  statusText: 'Created',
  headers: {
    'X-Message': 'Hello',
    'Content-Type': 'text/plain',
    'Content-Length': '22',
  },
})

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.notFound()

Return the Not Found Response.

app.get('/notfound', (c) => {
  return c.notFound()
})

c.redirect()

Redirect, default status code is 302.

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

c.res

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

c.event

// FetchEvent object
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
  ...
})

fire

app.fire() do this.

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

fetch

app.fetch for Cloudflare Module Worker syntax.

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

/*
or just do:
export default app
*/

request

request is a useful method for testing.

test('GET /hello is ok', async () => {
  const res = await app.request('http://localhost/hello')
  expect(res.status).toBe(200)
})

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.

---

Caution

Wrangler 1.x does not support importing middleware. We recommend two ways:

1. Use Wragler 2.0 Beta.
2. Build without webpack 4.x. For example, you can use esbuild. See the starter template.

---

1. npm init

Make a npm skeleton directory.

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

2. wrangler init

Initialize as a wrangler project.

$ npx wrangler@beta init

Answer the questions. If you want, you can answer y.

Would you like to install wrangler into your package.json? (y/n) <--- n
Would you like to use TypeScript? (y/n) <--- n
Would you like to create a Worker at src/index.js? (y/n) <--- n

3. npm install hono

Install hono from the npm registry.

$ npm i hono

4. Write your app

Only 4 lines!!

// index.js
import { Hono } from 'hono'
const app = new Hono()

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

app.fire()

5. Run

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

$ npx wrangler@beta dev index.js

6. Publish

Deploy to Cloudflare. That's all!

$ npx wrangler@beta publish index.js

Starter template

You can start making your Cloudflare Workers application with the starter template. It is really minimal using TypeScript, esbuild, and Miniflare.

To generate a project skelton, run this command.

$ wrangler generate my-app https://github.com/yusukebe/hono-minimal

Related projects

Implementation of the original router TrieRouter is inspired by goblin. RegExpRouter is inspired by Router::Boom. 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
• Router::Boom https://github.com/tokuhirom/Router-Boom

Contributing

Contributions Welcome! You can contribute by the following way.

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

Let's make Hono together!

Contributors

Thanks to all contributors!

Author

Yusuke Wada https://github.com/yusukebe

License

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