Wraps a resource to use new TypeScript / JavaScript (await) using keyword

makeDisposable.ts

import redis from "redis";
const { REDIS_PASSWORD } = process.env;

async function makeDisposable<T extends object>(
	resource: T,
	{
		onDispose,
		onInit,
	}: {
		onDispose?: (resource: T) => Promise<void>;
		onInit?: (resource: T) => Promise<void>;
	} = {},
): Promise<T & { [Symbol.asyncDispose]: () => Promise<void> }> {
	const handler: ProxyHandler<T> = {
		get(target: T, prop: string | symbol, receiver: unknown): unknown {
			if (prop === Symbol.asyncDispose) {
				return async () => {
					await onDispose?.(target);
				};
			}
			const value = Reflect.get(target, prop, target);
			return typeof value === "function" ? value.bind(target) : value;
		},
	};

	const proxy = new Proxy(resource, handler) as T & {
		[Symbol.asyncDispose]: () => Promise<void>;
	};

	await onInit?.(resource);

	return proxy;
}

async function main() {
	await using client = await makeDisposable(
		redis.createClient({
			password: REDIS_PASSWORD,
		}),
		{
			onInit: async (resource) => {
				// console.log("Initializing Redis client");
				await resource.connect();
			},
			onDispose: async (resource) => {
				// console.log("Disposing Redis client");
				await resource.disconnect();
			},
		},
	);

	const test = await client.get("test");

	console.log({ test });
}

main();