🌉 Nuxt Bridge

Experience Nuxt 3 features on existing Nuxt 2 projects.

Bridge is a forward-compatibility layer that allows you to experience many of the new Nuxt 3 features by simply installing and enabling a Nuxt module.

Using Nuxt Bridge, you can make sure your project is (almost) ready for Nuxt 3 and have the best developer experience without needing a major rewrite or risk breaking changes.

⚠️ Note: Nuxt Bridge provides identical features to Nuxt 3 (Nuxt 3 docs) but there are some limitations, notably that useAsyncData and useFetch composables are not available. Please read the rest of this page for details.

⚠️ Note: Nuxt Bridge does not support Internet Explorer. Supported browsers are listed at https://caniuse.com/es6-module-dynamic-import.

🌱 Note: If you're starting a fresh Nuxt project, please skip this module and directly go to the Nuxt 3 Installation.

💻 Development

Clone repository
Ensure you have the latest LTS version of Node.js installed
Enable Corepack using corepack enable to enable pnpm and yarn
Install dependencies with pnpm install
Run pnpm dev:prepare to activate passive development
Open playground with pnpm dev

Learn more about in our documentation on how to contribute to Nuxt.

Installation

Upgrade to the latest Nuxt 2

Make sure your dev server (nuxt dev) isn't running, remove any package lock files (package-lock.json, yarn.lock or pnpm-lock.yaml), and install the latest nuxt version:

- "nuxt": "^2.15.0"
+ "nuxt": "^2.16.0"

Then, reinstall your dependencies:

# Using yarn
yarn install

# Using npm
npm install

# Using pnpm
pnpm install

Once the installation is complete, make sure both development and production builds are working as expected before proceeding.

Install Nuxt Bridge

Install @nuxt/bridge-edge as a development dependency:

# Using yarn
yarn add --dev @nuxt/bridge@npm:@nuxt/bridge-edge

# Using npm
npm install -D @nuxt/bridge@npm:@nuxt/bridge-edge

# Using pnpm
pnpm install -D @nuxt/bridge@npm:@nuxt/bridge-edge

Update your scripts

You will also need to update your scripts within your package.json to reflect the fact that Nuxt will now produce a Nitro server as build output.

Nuxi

Nuxt 3 introduced the new Nuxt CLI command nuxi. Update your scripts as follows to leverage the better support from Nuxt Bridge:

{
  "scripts": {
-   "dev": "nuxt",
+   "dev": "nuxi dev",
-   "build": "nuxt build",
+   "build": "nuxi build",
-   "start": "nuxt start",
+   "start": "nuxi preview"
  }
}

Static target

If you have set target: 'static' in your nuxt.config then you need to ensure that you update your build script to be nuxi generate.

{
  "scripts": {
    "build": "nuxi generate"
  }
}

Server target

For all other situations, you can use the nuxi build command.

{
  "scripts": {
    "build": "nuxi build",
    "start": "nuxi preview"
  }
}

Update `nuxt.config`

Please make sure to avoid any CommonJS syntax such as module.exports, require or require.resolve in your config file. It will soon be deprecated and unsupported.

You can use static import, dynamic import() and export default instead. Using TypeScript by renaming to nuxt.config.ts is also possible and recommended.

import { defineNuxtConfig } from '@nuxt/bridge'

export default defineNuxtConfig({
  // Your existing configuration
})

Update `tsconfig.json`

If you are using TypeScript, you can edit your tsconfig.json to benefit from auto-generated Nuxt types:

{
+ "extends": "./.nuxt/tsconfig.json",
  "compilerOptions": {
    ...
  }
}

Keep in mind that all options extended from ./.nuxt/tsconfig.json will be overwritten by the options defined in your tsconfig.json.

Overwriting options such as "compilerOptions.paths" with your own configuration will lead TypeScript to not factor in the module resolutions from ./.nuxt/tsconfig.json. This can lead to module resolutions such as #imports not being recognized.

In case you need to extend options provided by ./.nuxt/tsconfig.json further, you can use the alias property withing your nuxt.config. nuxi will pick them up and extend ./.nuxt/tsconfig.json accordingly.

Migrate Composition API

If you were using @vue/composition-api or @nuxtjs/composition-api, please read the composition api migration guide.

Migrate from CommonJS to ESM

Nuxt 3 natively supports TypeScript and ECMAScript Modules. Please check Native ES Modules for more info and upgrading.

Remove incompatible and obsolete modules

Remove @nuxt/content (1.x). A rewrite for Nuxt 3 is planned (2.x)
Remove nuxt-vite: Bridge enables same functionality
Remove @nuxt/typescript-build: Bridge enables same functionality
Remove @nuxt/typescript-runtime and nuxt-ts: Nuxt 2 has built-in runtime support
Remove @nuxt/nitro: Bridge injects same functionality
Remove @vue/composition-api from your dependencies (migration guide).
Remove @nuxtjs/composition-api from your dependencies (and from your modules in nuxt.config) (migration guide).

Exclude built Nitro folder from git

Add the folder .output to the .gitignore file.

Ensure everything goes well

✔️ Try with nuxi dev and nuxi build (or nuxi generate) to see if everything goes well.

🐛 Is something wrong? Please let us know by creating an issue. Also, you can easily disable the bridge in the meantime:

import { defineNuxtConfig } from '@nuxt/bridge'

export default defineNuxtConfig({
  bridge: false // Temporarily disable bridge integration
})

New plugins format (optional)

You can now migrate to the Nuxt 3 plugins API, which is slightly different in format from Nuxt 2.

Plugins now take only one argument (nuxtApp). You can find out more in the docs.

export default defineNuxtPlugin(nuxtApp => {
  nuxtApp.provide('injected', () => 'my injected function')
  // now available on `nuxtApp.$injected`
})

If you want to use the new Nuxt composables (such as useNuxtApp or useRuntimeConfig) within your plugins, you will need to use the defineNuxtPlugin helper for those plugins.

Although a compatibility interface is provided via nuxtApp.vueApp you should avoid registering plugins, directives, mixins or components this way without adding your own logic to ensure they are not installed more than once, or this may cause a memory leak.

New `useHead` (optional)

Nuxt Bridge provides a new Nuxt 3 meta API that can be accessed with a new useHead composable.

<script setup>
useHead({
  title: 'My Nuxt App',
})
</script>

You will also need to enable this feature explicitly in your nuxt.config:

import { defineNuxtConfig } from '@nuxt/bridge'

export default defineNuxtConfig({
  bridge: {
    meta: true
  }
})

This useHead composable uses @vueuse/head under the hood (rather than vue-meta) to manipulate your <head>. Accordingly, we recommend not to use both the native Nuxt 2 head() properties as well as useHead, as they may conflict.

For more information on how to use this composable, see the docs.

Feature Flags

You can optionally disable some features from bridge or opt-in to less stable ones. In normal circumstances, it is always best to stick with defaults!

You can check packages/bridge/src/module.ts for latest defaults.

import { defineNuxtConfig } from '@nuxt/bridge'

export default defineNuxtConfig({
  bridge: {

    // -- Opt-in features --

    // Use Vite as the bundler instead of webpack 4
    // vite: true,

    // Enable Nuxt 3 compatible useHead
    // meta: true,


    // -- Default features --

    // Use legacy server instead of Nitro
    // nitro: false,

    // Use legacy generator rather than new nitro prerenderer
    // nitroGenerator: false,

    // Disable nuxt 3 compatible `nuxtApp` interface
    // app: false,

    // Disable Composition API support
    // capi: false,

    // ... or just disable legacy Composition API support
    // capi: {
    //   legacy: false
    // },

    // Do not transpile modules
    // transpile: false,

    // Disable composables auto importing
    // imports: false,

    // Do not warn about module incompatibilities
    // constraints: false
  },

  vite: {
    // Config for Vite
  }
})

License

MIT

ColinRosati/bridge