// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license. import { AsyncLocalStorage, AsyncResource } from "node:async_hooks"; import { assert, assertEquals } from "@test_util/std/assert/mod.ts"; Deno.test(async function foo() { const asyncLocalStorage = new AsyncLocalStorage(); const out: string[] = []; function logWithId(msg: string) { const id = asyncLocalStorage.getStore(); out.push(`${id !== undefined ? id : "-"}: ${msg}`); } async function exec() { logWithId("start"); await new Promise((resolve) => setTimeout(resolve, 100)); logWithId("finish"); } for (const foo of [1, 2, 3]) { asyncLocalStorage.run(foo, exec); } await new Promise((resolve) => setTimeout(resolve, 500)); assertEquals(out, [ "1: start", "2: start", "3: start", "1: finish", "2: finish", "3: finish", ]); }); Deno.test(async function bar() { let differentScopeDone = false; const als = new AsyncLocalStorage(); const ac = new AbortController(); const server = Deno.serve({ signal: ac.signal, port: 4000, }, () => { const differentScope = als.run(123, () => AsyncResource.bind(() => { differentScopeDone = true; })); return als.run("Hello World", async () => { // differentScope is attached to a different async context, so // it will see a different value for als.getStore() (123) setTimeout(differentScope, 5); // Some simulated async delay. await new Promise((res) => setTimeout(res, 10)); return new Response(als.getStore() as string); // "Hello World" }); }); const res = await fetch("http://localhost:4000"); assertEquals(await res.text(), "Hello World"); ac.abort(); await server.finished; assert(differentScopeDone); }); Deno.test(async function nested() { const als = new AsyncLocalStorage(); const deferred = Promise.withResolvers(); const deferred1 = Promise.withResolvers(); als.run(null, () => { als.run({ x: 1 }, () => { deferred.resolve(als.getStore()); }); deferred1.resolve(als.getStore()); }); assertEquals(await deferred.promise, { x: 1 }); assertEquals(await deferred1.promise, null); });