@hono/vite-dev-server

@hono/vite-dev-server

@hono/vite-dev-server is a Vite Plugin that provides a custom dev-server for fetch-based web applications like those using Hono. You can develop your application with Vite. It's fast.

Features

• Support any fetch-based applications.
• Hono applications run on.
• Fast by Vite.
• HMR (Only for the Client-side. Currently, Vite doesn't support HMR for SSR).
• Supporting Cloudflare Bindings.
• Also runs on Bun.

Demo

https://github.com/honojs/vite-plugins/assets/10682/a93ee4c5-2e1a-4b17-8bb2-64f955f2f0b0

Supported applications

You can run any application on @hono/vite-dev-server that uses fetch and is built with Web Standard APIs. The minimal application is the following.

export default {
  fetch(_request: Request) {
    return new Response('Hello Vite!')
  },
}

This code can also run on Cloudflare Workers or Bun. And if you change the entry point, you can run on Deno, Vercel, Lagon, and other platforms.

Hono is designed for fetch-based application like this.

import { Hono } from 'hono'

const app = new Hono()

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

export default app

So, any Hono application will run on @hono/vite-dev-server.

Usage

Installation

You can install vite and @hono/vite-dev-server via npm.

npm i -D vite @hono/vite-dev-server

Or you can install them with Bun.

bun add vite @hono/vite-dev-server

Settings

Add "type": "module" to your package.json. Then, create vite.config.ts and edit it.

import { defineConfig } from 'vite'
import devServer from '@hono/vite-dev-server'

export default defineConfig({
  plugins: [
    devServer({
      entry: 'src/index.ts', // The file path of your application.
    }),
  ],
})

Development

Just run vite.

npm exec vite

Or

bunx --bun vite

Options

The options are below. WorkerOptions imported from miniflare are used for Cloudflare Bindings.

export type DevServerOptions = {
  entry?: string
  injectClientScript?: boolean
  exclude?: (string | RegExp)[]
  env?: Env | EnvFunc
}

Default values:

export const defaultOptions: Required<Omit<DevServerOptions, 'cf'>> = {
  entry: './src/index.ts',
  injectClientScript: true,
  exclude: [
    /.*\.ts$/,
    /.*\.tsx$/,
    /^\/@.+$/,
    /^\/favicon\.ico$/,
    /^\/static\/.+/,
    /^\/node_modules\/.*/,
  ],
}

injectClientScript

If it's true and the response content-type is "HTML", inject the script that enables Hot-reload. default is true.

exclude

The paths which are not served by the dev-server.

If you have static files in public/assets/* and want to return them, exclude /assets/* as follows:

import devServer, { defaultOptions } from '@hono/vite-dev-server'
import { defineConfig } from 'vite'

export default defineConfig({
  plugins: [
    devServer({
      exclude: ['/assets/.*', ...defaultOptions.exclude],
    }),
  ],
})

env

You can pass ENV variables to your application by setting the env option. ENV values can be accessed using c.env in your Hono application.

Presets are available to define the ENV.

ENV presets

Cloudflare Pages

You can use Cloudflare Pages ENV presets, which allow you to access bindings such as variables, KV, D1, and others.

import { getEnv } from '@hono/vite-dev-server/cloudflare-pages'

export default defineConfig({
  plugins: [
    devServer({
      env: getEnv({
        bindings: {
          NAME: 'Hono',
        },
        kvNamespaces: ['MY_KV'],
      }),
    }),
  ],
})

These Bindings are emulated by Miniflare in the local.

D1

When using D1, your app will read .mf/d1/DB/db.sqlite which is generated automatically with the following configuration:

export default defineConfig({
  plugins: [
    devServer({
      cf: {
        d1Databases: ['DB'],
        d1Persist: true,
      },
    }),
  ],
})

Client-side

You can write client-side scripts and import them into your application using Vite's features. If /src/client.ts is the entry point, simply write it in the script tag. Additionally, import.meta.env.PROD is useful for detecting whether it's running on a dev server or in the build phase.

app.get('/', (c) => {
  return c.html(
    <html>
      <head>
        {import.meta.env.PROD ? (
          <>
            <script type='module' src='/static/client.js'></script>
          </>
        ) : (
          <>
            <script type='module' src='/src/client.ts'></script>
          </>
        )}
      </head>
      <body>
        <h1>Hello</h1>
      </body>
    </html>
  )
})

In order to build the script properly, you can use the example config file vite.config.ts as shown below.

import { defineConfig } from 'vite'
import devServer from '@hono/vite-dev-server'
import pages from '@hono/vite-cloudflare-pages'

export default defineConfig(({ mode }) => {
  if (mode === 'client') {
    return {
      build: {
        lib: {
          entry: './src/client.ts',
          formats: ['es'],
          fileName: 'client',
          name: 'client',
        },
        rollupOptions: {
          output: {
            dir: './dist/static',
          },
        },
        emptyOutDir: false,
        copyPublicDir: false,
      },
    }
  } else {
    return {
      plugins: [
        pages(),
        devServer({
          entry: 'src/index.tsx',
        }),
      ],
    }
  }
})

You can run the following command to build the client script.

vite build --mode client

Authors

• Yusuke Wada https://github.com/yusukebe

License

MIT