createBunAssetReader

createBunAssetReader({ root, assets }) is Bun's public file reader. Like the Node reader, it only responds to paths in the build's asset manifest and returns null for all others, which are never looked up on disk; the difference is that it reads with Bun.file, which Bun sends without going through JavaScript.

Usage#

import { createServerApp } from "@meekojs/meeko/server";
import { createBunAssetReader } from "@meekojs/meeko/bun";

const app = await createServerApp({
  manifest, load, runtime, production: true,
  assets: createBunAssetReader({ root: new URL("./client/", import.meta.url), assets: manifest.assets ?? {} }),
});

Type#

function createBunAssetReader(options: BunAssetReaderOptions): AssetReader

interface BunAssetReaderOptions {
	readonly root: string | URL
	readonly assets: AssetManifest
}

interface AssetReader {
	get(pathname: string, request: Request): Promise<Response | null>
}

Parameters#

Return value#

An AssetReader with get(pathname, request): null for a path not in assets or a method other than GET and HEAD; 304 if If-None-Match matches; 200 with content-type, ETag, content-length and cache-control (public, max-age=31536000, immutable for Vite's hashed files, public, max-age=0, must-revalidate for the rest).

Examples#

Test the reader in Bun#

// bun test assets.test.ts
import { expect, test } from "bun:test";
import { createBunAssetReader } from "@meekojs/meeko/bun";

test("only serves what is in the manifest", async () => {
  const assets = createBunAssetReader({ root: new URL("./fixtures/client/", import.meta.url), assets: { "/robots.txt": { type: "text/plain", etag: '"r1"', size: 25 } } });
  expect((await assets.get("/robots.txt", new Request("http://x/robots.txt")))?.status).toBe(200);
  expect(await assets.get("/../package.json", new Request("http://x/../package.json"))).toBeNull();
});

A cache in front of Bun#

GET /assets/entry-4f2a.js  → 200, cache-control: public, max-age=31536000, immutable
GET /assets/entry-4f2a.js  If-None-Match: "…" → 304 without reading the file

Common mistakes#

Run it in Node#

// node server.mjs
await createBunAssetReader({ root, assets }).get("/robots.txt", request);

The first read throws Error: The Meeko Bun adapter requires the Bun runtime. In Node, use createNodeAssetReader.

import { createNodeAssetReader } from "@meekojs/meeko/node";
const assets = createNodeAssetReader({ root: fileURLToPath(new URL("./client/", import.meta.url)), assets: manifest.assets ?? {} });

A manifest file missing from the folder#

.meeko/output/bun/ copied without client/assets/

A request for a listed file rejects with Error: Missing build asset /assets/entry-4f2a.js, which the application converts to 500 and sends to onError. Copy the complete output folder.

.meeko/output/bun/ complete: index.js, chunks/, client/ and prerender/

Notes#

• Security. Paths are looked up in the manifest without decoding: no traversal matches.
• HEAD and 304. They do not open the file.
• Bun only. Importing @meekojs/meeko/bun in Node does not fail; reading a file does.

Related#

• createBunServerThe fetch and websocket handlers for serving a Meeko application with Bun.serve, using Bun's native WebSocket for Socket and its payload, backpressure and idle limits.
• createNodeAssetReaderServes only build files listed in the asset manifest from disk on Node, using streaming and Meeko's ETag, HEAD, 304 and cache policy.
• createDenoAssetReaderStreams only build files listed in the asset manifest using Deno.open, with ETag, HEAD, 304 and Meeko's cache policy.
• BunMeeko as a full-stack framework