bun-plugin-sveltekit

A Bun plugin to handle SvelteKit-specific imports when running scripts with Bun.

The Problem

When you have a SvelteKit application and use Bun as your runtime, you often want to run scripts that import (directly or indirectly) SvelteKit-specific modules. For example:

In your SvelteKit app:

import { GITHUB_TOKEN } from '$env/static/private';

In your Bun CLI scripts:

const GITHUB_TOKEN = process.env.GITHUB_TOKEN; // or Bun.env.DATABASE_URL

This creates a challenge when building shared utility functions that need to work in both environments - the SvelteKit app (requiring special imports) and Bun CLI scripts (using process.env).

The Solution

This plugin allows Bun to resolve SvelteKit's virtual modules, enabling you to use the same imports in both your SvelteKit app and standalone Bun scripts.

Installation

Download the plugin file directly:

curl -O https://raw.githubusercontent.com/mquandalle/bun-plugin-sveltekit/main/bun-plugin-sveltekit.ts

Then configure your bunfig.toml to preload the plugin:

preload = ["./bun-plugin-sveltekit.ts"]

See Bun's plugin documentation for more details on plugin configuration.

How It Works

The plugin registers handlers for SvelteKit's virtual modules:

• $env/static/private → Maps to Bun.env (equivalent to process.env)
• $app/environment → Returns { dev: true }

This allows your scripts to use SvelteKit imports without modification:

// This now works in both SvelteKit and Bun CLI scripts!
import { DATABASE_URL } from '$env/static/private';
import { dev } from '$app/environment';

console.log('Database:', DATABASE_URL);
console.log('Dev mode:', dev);

Note that $lib alias is automatically handled by Bun

Current Support

Currently, the plugin only supports:

• $env/static/private
• $app/environment

It's easy to extend support for other SvelteKit modules by adding more module handlers in the plugin.

Alternatives

vite-node

An alternative approach is using vite-node, which can execute scripts with full Vite transformation pipeline, including SvelteKit's module resolution. This might be a better choice if you need more comprehensive SvelteKit module support.

Use Cases

• Running database migrations that share models with your SvelteKit app
• Building CLI tools that reuse your application's business logic
• Creating scheduled jobs or background workers
• Testing utilities that depend on SvelteKit modules

Contributing

Feel free to submit issues or PRs to add support for more SvelteKit modules!

License

MIT