svelte-adapter-deno

Adapter for SvelteKit apps that generates a standalone Deno server.

Usage

Install with npm i -D svelte-adapter-deno, then add the adapter to your svelte.config.js:

// svelte.config.js
import adapter from 'svelte-adapter-deno';

export default {
  kit: {
    adapter: adapter({
      // default options are shown
      out: 'build',
      deps: './deps.ts' // (relative to adapter-deno package)
    })
  }
};

After building the server (npm run build), use the following command to start:

# with the default build directory
deno run --allow-env --allow-read --allow-net build/index.js

# with a custom build directory
deno run --allow-env --allow-read --allow-net path/to/build/index.js

You can use the deployctl GitHub Action to automatically deploy your app in Deno Deploy:

.github/workflows/ci.yml

name: ci

on:
  push:
    branches:
      - main
  pull_request:
    branches:
      - main

jobs:
  deploy:
    name: deploy
    runs-on: ubuntu-latest
    permissions:
      id-token: write
      contents: read

    steps:
      - name: Clone repository
        uses: actions/checkout@v2

      - name: Install Node
        uses: actions/setup-node@v2
        with:
          node-version: 16

      - name: Cache pnpm modules
        uses: actions/cache@v2
        with:
          path: ~/.pnpm-store
          key: ${{ runner.os }}-${{ hashFiles('**/pnpm-lock.yaml') }}
          restore-keys: |
            ${{ runner.os }}-

      - name: Install pnpm and node_modules
        uses: pnpm/action-setup@v2
        with:
          version: latest
          run_install: true

      - name: Build site
        run: pnpm build
        working-directory: '<root>' # if necessary, should contain {out}

      - name: Deploy to Deno Deploy
        uses: denoland/deployctl@v1
        with:
          project: <YOUR PROJECT NAME>
          entrypoint: '{out}/index.js' # same as `out` option in config
          root: '<root>' # if necessary

The server needs at least the following permissions to run:

• allow-env - allow environment access, to support runtime configuration via runtime variables (can be further restricted to include just the necessary variables)
• allow-read - allow file system read access (can be further restricted to include just the necessary directories)
• allow-net - allow network access (can be further restricted to include just the necessary domains)

Additionally, --no-check can be used if deno complains while typechecking upstream dependencies.

Options

out

The directory to build the server to. It defaults to build — i.e. deno run --allow-env --allow-read --allow-net build/index.js would start the server locally after it has been created.

precompress

Enables precompressing using gzip and brotli for assets and prerendered pages. It defaults to false.

deps

The file re-exporting external runtime dependencies (deps.ts by convention in Deno). It defaults to the deps.ts included in the package.

Environment variables

By default, the server will accept connections on 0.0.0.0 using port 3000. These can be customised with the PORT and HOST environment variables:

HOST=127.0.0.1 PORT=4000 deno run --allow-env --allow-read --allow-net build/server.js

You can specify different environment variables if necessary using the env option.

Advanced Configuration

esbuild

As an escape hatch, you may optionally specify a function which will receive the final esbuild options generated by this adapter and returns a modified esbuild configuration. The result of this function will be passed as-is to esbuild. The function can be async.

For example, you may wish to add a plugin:

adapterDeno({
  esbuild(defaultOptions) {
    return {
      ...defaultOptions,
      plugins: []
    };
  }
});

The default options for this version are as follows:

{
  entryPoints: ['.svelte-kit/deno/index.js'],
  outfile: 'build/index.js',
  bundle: true,
  format: 'esm',
  platform: 'neutral',
  sourcemap: 'external'
}

License

MIT