hono/README.md

Hono

Hono [炎] - Tiny web framework for Cloudflare Workers and others.

const { Hono } = require('hono')
const app = new Hono()

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

app.fire()

Hono[炎] - means flame🔥 in Japanese - is small, fast and simple web flamework for a Service Workers API based serverless service such as Cloudflare Workers and Fastly Compute@Edge. Because Hono does not depend on any NPM packages, it's easy to install, setup, and deploy. Although Hono has a router, context object, and middleware including builtin. Mostly web application like a Web API can be made.

In the case of Cloudflare Workers, there are wrangler and miniflare.You can develop the application locally and publish it with few commands.

It's amazing that the experience of writing code with Hono. Enjoy!

Feature

• Fast - the router is implemented with Trie-Tree structure.
• Tiny - zero dependencies, using Web standard API.
• Flexible - you can make your own middleware.
• Easy - simple API, builtin middleware, and written in TypeScript.
• Optimized - for Cloudflare Workers or Fastly Compute@Edge.

Benchmark

Hono is fastest compared to other routers for Cloudflare Workers.

hono x 758,264 ops/sec ±5.41% (75 runs sampled)
itty-router x 158,359 ops/sec ±3.21% (89 runs sampled)
sunder x 297,581 ops/sec ±4.74% (83 runs sampled)
Fastest is hono
✨  Done in 42.84s.

Hono in 1 minute

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

Install

You can install from npm public 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()

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

const { Hono, Middleware } = require('hono')

...

app.use('*', Middleware.poweredBy())
app.use('*', Middleware.logger())

Available builtin middleware are listed on src/middleware directory.

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 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

If you want to 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.text()

Render text as Content-Type:text/plain:

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

c.json()

Render text as Content-Type:application/json:

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

fire

app.fire() do:

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

Cloudflare Workers with Hono

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
$ ch 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 line!!

const { Hono } = require('hono')
const app = new Hono()

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

app.fire()

6. Run

Run the development server locally.

$ 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 and Sunder 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

Contributing

Contributions Welcome! You can contribute by the following way:

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

If you can, please!

Author

Yusuke Wada https://github.com/yusukebe

License

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