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// Copyright (c) 2025 Cloudflare, Inc.
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// Licensed under the Apache 2.0 license found in the LICENSE file or at:
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//     https://opensource.org/licenses/Apache-2.0
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import { AsyncLocalStorage } from 'node:async_hooks';
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import { strictEqual } from 'node:assert';
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// This test verifies that the AsyncLocalStorage snapshot and bind APIs appropriately
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// throw an error when called from outside the request context in which they were created.
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// This is a workers specific limitation and is not present in Node.js.
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// The test will only work if the associated compatibility flag is enabled.
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strictEqual(
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  Cloudflare.compatibilityFlags.bind_asynclocalstorage_snapshot_to_request,
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  true
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);
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const kErr =
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  'Cannot call this AsyncLocalStorage bound function outside of the ' +
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  'request in which it was created.';
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export const test = {
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  async test(_, env) {
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    const resp = await env.subrequest.fetch(
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      'http://AsyncLocalStorage/snapshot'
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    );
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    strictEqual(resp.status, 200);
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    strictEqual(await resp.text(), 'ok');
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    const resp2 = await env.subrequest.fetch(
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      'http://AsyncLocalStorage/snapshot'
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    );
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    strictEqual(resp2.status, 500);
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    strictEqual(await resp2.text(), kErr);
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    const resp3 = await env.subrequest.fetch('http://AsyncLocalStorage/bind');
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    strictEqual(resp3.status, 200);
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    strictEqual(await resp3.text(), 'ok');
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    const resp4 = await env.subrequest.fetch('http://AsyncLocalStorage/bind');
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    strictEqual(resp4.status, 500);
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    strictEqual(await resp4.text(), kErr);
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  },
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};
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let snapshot;
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let boundFn;
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const als = new AsyncLocalStorage();
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const noRequestSnapshot = als.run(123, () => AsyncLocalStorage.snapshot());
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export default {
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  async fetch(req) {
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    // A snapshot created outside of a request can still be used, and can
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    // perform i/o operation...
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    strictEqual(
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      noRequestSnapshot(() => {
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        // Works if no error is thrown. We don't care about the actual
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        // callback here.
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        setTimeout(() => {}, 0);
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        return als.getStore();
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      }),
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      123
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    );
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    try {
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      if (req.url.endsWith('/snapshot')) {
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        snapshot ??= AsyncLocalStorage.snapshot();
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        snapshot(() => {});
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        return new Response('ok');
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      } else if (req.url.endsWith('/bind')) {
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        boundFn ??= AsyncLocalStorage.bind(() => {});
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        boundFn();
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        return new Response('ok');
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      }
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      throw new Error('Unknown request');
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    } catch (err) {
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      return new Response(err.message, { status: 500 });
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    }
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  },
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};