# Hono Hono[炎] - _**means flame🔥 in Japanese**_ - is small, simple, and ultrafast web framework for a Service Workers API based serverless such as Cloudflare Workers and Fastly Compute@Edge. ```js 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. Not use loops. - **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. ```plain hono x 723,296 ops/sec ±5.97% (72 runs sampled) itty-router x 160,811 ops/sec ±3.35% (91 runs sampled) sunder x 302,867 ops/sec ±5.02% (81 runs sampled) worktop x 199,306 ops/sec ±5.12% (78 runs sampled) Fastest is hono ✨ Done in 50.19s. ``` ## Hono in 1 minute Below is a demonstration to create an application of Cloudflare Workers with Hono. ![Demo](https://user-images.githubusercontent.com/10682/151973526-342644f9-71c5-4fee-81f4-64a7558bb192.gif) Now, the named path parameter has types. ![Demo](https://user-images.githubusercontent.com/10682/154179671-9e491597-6778-44ac-a8e6-4483d7ad5393.png) ## Install You can install Hono from npm registry: ```sh yarn add hono ``` or ```sh 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.**fire**() - app.**fetch**(request, env, event) ## Routing ### Basic `app.HTTP_METHOD` ```js // 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') }) ``` `app.all` ```js // Any HTTP methods app.all('/hello', (c) => c.text('Any Method /hello')) ``` ### Named Parameter ```js app.get('/user/:name', (c) => { const name = c.req.param('name') ... }) ``` ### Regexp ```js app.get('/post/:date{[0-9]+}/:title{[a-z]+}', (c) => { const date = c.req.param('date') const title = c.req.param('title') ... ``` ### Nested route ```js 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 ``` ### Custom 404 Response You can customize 404 Not Found response: ```js app.get('*', (c) => { return c.text('Custom 404 Error', 404) }) ``` ### no strict If `strict` is set `false`, `/hello`and`/hello/` are treated the same: ```js const app = new Hono({ strict: false }) app.get('/hello', (c) => c.text('/hello or /hello/')) ``` Default is `true`. ## async/await ```js app.get('/fetch-url', async (c) => { const response = await fetch('https://example.com/') return c.text(`Status is ${response.status}`) }) ``` ## Middleware ### Builtin Middleware ```js import { Hono } from 'hono' import { poweredBy } from 'hono/powered-by' import { logger } from 'hono/logger' import { basicAuth } from 'hono/basicAuth' const app = new Hono() app.use('*', poweredBy()) app.use('*', logger()) app.use('/auth/*', basicAuth({ username: 'hono', password: 'acoolproject' })) ``` Available builtin middleware are listed on [src/middleware](https://github.com/yusukebe/hono/tree/master/src/middleware). ### Custom Middleware You can write your own middleware: ```js // Custom logger app.use('*', async (c, next) => { console.log(`[${c.req.method}] ${c.req.url}`) await next() }) // Add a custom header app.use('/message/*', async (c, next) => { await next() await c.header('x-message', 'This is middleware!') }) app.get('/message/hello', (c) => c.text('Hello Middleware!')) ``` ### Handling Error ```js app.use('*', async (c, next) => { try { await next() } catch (err) { console.error(`${err}`) c.res = c.text('Custom Error Message', { status: 500 }) } }) ``` ## Context To handle Request and Reponse, you can use Context object: ### c.req ```js // 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 ```js app.get('/welcome', (c) => { c.header('X-Message', 'Hello!') c.header('Content-Type', 'text/plain') c.status(201) return c.body('Thank you for comming') /* Same as: return 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`: ```js app.get('/say', (c) => { return c.text('Hello!') }) ``` ### c.json() Render JSON as `Content-Type:application/json`: ```js app.get('/api', (c) => { return c.json({ message: 'Hello!' }) }) ``` ### c.html() Render HTML as `Content-Type:text/html`: ```js app.get('/', (c) => { return c.html('

Hello! Hono!

') }) ``` ### c.redirect() Redirect, default status code is `302`: ```js app.get('/redirect', (c) => c.redirect('/')) app.get('/redirect-permanently', (c) => c.redirect('/', 301)) ``` ### c.res ```js // Response object app.use('/', (c, next) => { next() c.res.headers.append('X-Debug', 'Debug message') }) ``` ### c.event ```js // FetchEvent object app.use('*', async (c, next) => { c.event.waitUntil( ... ) await next() }) ``` ### c.env ```js // Environment object for Cloudflare Workers app.get('*', async c => { const counter = c.env.COUNTER ... }) ``` ## fire `app.fire()` do: ```js addEventListener('fetch', (event) => { event.respondWith(this.handleEvent(event)) }) ``` ## fetch `app.fetch()` is for Cloudflare Module Worker syntax. ```js export default { fetch(request: Request, env: Env, event: FetchEvent) { return app.fetch(request, env, event) }, } /* or just do this: export default app */ ``` ## 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](https://github.com/cloudflare/wrangler)" ```sh npm i @cloudflare/wrangler -g ``` ### 2. `npm init` Make npm skeleton directory. ```sh mkdir hono-example cd hono-example npm init -y ``` ### 3. `wrangler init` Init as a wrangler project. ```sh wrangler init ``` ### 4. `npm install hono` Install `hono` from npm registry. ```sh npm i hono ``` ### 5. Write your app Only 4 lines!! ```js 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. ```sh wrangler dev ``` ### 7. Publish Deploy to Cloudflare. That's all! ```sh wrangler publish ``` ## Related projects Implementation of the router is inspired by [goblin](https://github.com/bmf-san/goblin). API design is inspired by [express](https://github.com/expressjs/express) and [koa](https://github.com/koajs/koa). [itty-router](https://github.com/kwhitley/itty-router), [Sunder](https://github.com/SunderJS/sunder), and [worktop](https://github.com/lukeed/worktop) are the other routers or frameworks for Cloudflare Workers. - express - koa - itty-router - Sunder - goblin - 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! ## Contributors Thanks to [all contributors](https://github.com/yusukebe/hono/graphs/contributors)! ## Author Yusuke Wada ## License Distributed under the MIT License. See [LICENSE](LICENSE) for more information.