Getting the SQLite DB path for a local R2 bucket

bucket-path.mts

#!/usr/bin/env yarn -s tsx

import { createHash, createHmac } from "node:crypto";
import { parseArgs } from "node:util";

const uniqueKey = "miniflare-R2BucketObject";

// Adapted from https://github.com/cloudflare/workers-sdk/blob/2df1d066c/packages/miniflare/src/plugins/shared/index.ts#L236-L249
function durableObjectNamespaceIdFromName(name: string) {
	const key = createHash("sha256").update(uniqueKey).digest();
	const nameHmac = createHmac("sha256", key).update(name).digest().subarray(0, 16);
	const hmac = createHmac("sha256", key).update(nameHmac).digest().subarray(0, 16);
	return Buffer.concat([nameHmac, hmac]).toString("hex");
}

function dbFromName(name: string) {
	return `.wrangler/state/v3/r2/${uniqueKey}/${durableObjectNamespaceIdFromName(name)}.sqlite`;
}

// Returns the path to a local R2 bucket's SQLite DB.
const {positionals: [name]} = parseArgs({allowPositionals: true});
if(!name) {
	console.error(`Usage: bucket-path BUCKET_NAME`);
	process.exitCode = 1;
}
else process.stdout.write(dbFromName(name));