Deno
Deno is a JavaScript runtime built on V8. It's not Node.js. Hono also works on Deno.
You can use Hono, write the code with TypeScript, run the application with the deno
command, and deploy it to "Deno Deploy".
1. Install Deno
First, install deno
command. Please refer to the official document.
2. Setup
A starter for Deno is available. Start your project with the deno init
command.
deno init --npm hono my-app --template=deno
Move into my-app
. For Deno, you don't have to install Hono explicitly.
cd my-app
3. Hello World
Edit main.ts
:
import { Hono } from 'hono'
const app = new Hono()
app.get('/', (c) => c.text('Hello Deno!'))
Deno.serve(app.fetch)
4. Run
Run the development server locally. Then, access http://localhost:8000
in your Web browser.
deno task start
Change port number
You can specify the port number by updating the arguments of Deno.serve
in main.ts
:
Deno.serve(app.fetch)
Deno.serve({ port: 8787 }, app.fetch)
Serve static files
To serve static files, use serveStatic
imported from hono/deno
.
import { Hono } from 'hono'
import { serveStatic } from 'hono/deno'
const app = new Hono()
app.use('/static/*', serveStatic({ root: './' }))
app.use('/favicon.ico', serveStatic({ path: './favicon.ico' }))
app.get('/', (c) => c.text('You can access: /static/hello.txt'))
app.get('*', serveStatic({ path: './static/fallback.txt' }))
Deno.serve(app.fetch)
For the above code, it will work well with the following directory structure.
./
├── favicon.ico
├── index.ts
└── static
├── demo
│ └── index.html
├── fallback.txt
├── hello.txt
└── images
└── dinotocat.png
rewriteRequestPath
If you want to map http://localhost:8000/static/*
to ./statics
, you can use the rewriteRequestPath
option:
app.get(
'/static/*',
serveStatic({
root: './',
rewriteRequestPath: (path) =>
path.replace(/^\/static/, '/statics'),
})
)
mimes
You can add MIME types with mimes
:
app.get(
'/static/*',
serveStatic({
mimes: {
m3u8: 'application/vnd.apple.mpegurl',
ts: 'video/mp2t',
},
})
)
onFound
You can specify handling when the requested file is found with onFound
:
app.get(
'/static/*',
serveStatic({
// ...
onFound: (_path, c) => {
c.header('Cache-Control', `public, immutable, max-age=31536000`)
},
})
)
onNotFound
You can specify handling when the requested file is not found with onNotFound
:
app.get(
'/static/*',
serveStatic({
onNotFound: (path, c) => {
console.log(`${path} is not found, you access ${c.req.path}`)
},
})
)
precompressed
The precompressed
option checks if files with extensions like .br
or .gz
are available and serves them based on the Accept-Encoding
header. It prioritizes Brotli, then Zstd, and Gzip. If none are available, it serves the original file.
app.get(
'/static/*',
serveStatic({
precompressed: true,
})
)
Deno Deploy
Deno Deploy is a serverless platform for running JavaScript and TypeScript applications in the cloud. It provides a management plane for deploying and running applications through integrations like GitHub deployment.
Hono also works on Deno Deploy. Please refer to the official document.
Testing
Testing the application on Deno is easy. You can write with Deno.test
and use assert
or assertEquals
from @std/assert.
deno add jsr:@std/assert
import { Hono } from 'hono'
import { assertEquals } from '@std/assert'
Deno.test('Hello World', async () => {
const app = new Hono()
app.get('/', (c) => c.text('Please test me'))
const res = await app.request('http://localhost/')
assertEquals(res.status, 200)
})
Then run the command:
deno test hello.ts
npm and JSR
Hono is available on both npm and JSR (the JavaScript Registry). You can use either npm:hono
or jsr:@hono/hono
in your deno.json
:
{
"imports": {
"hono": "jsr:@hono/hono"
"hono": "npm:hono"
}
}
When using third-party middleware, you may need to use Hono from the same registry as the middleware for proper TypeScript type inference. For example, if using the middleware from npm, you should also use Hono from npm:
{
"imports": {
"hono": "npm:hono",
"zod": "npm:zod",
"@hono/zod-validator": "npm:@hono/zod-validator"
}
}
We also provide many third-party middleware packages on JSR. When using the middleware on JSR, use Hono from JSR:
{
"imports": {
"hono": "jsr:@hono/hono",
"zod": "npm:zod",
"@hono/zod-validator": "jsr:@hono/zod-validator"
}
}