doc: improper description of AsyncLocalStorage behavior

[kjarmicki]

📗 API Reference Docs Problem

• Version: v12.18.2

• Platform: Linux kjarmicki-dell 4.15.0-109-generic Update binnary alternatives #110-Ubuntu SMP Tue Jun 23 02:39:32 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

• Subsystem: async_hooks

Affected URL(s):

• https://nodejs.org/api/async_hooks.html#async_hooks_asynclocalstorage_run_store_callback_args

Description

There's a section in the documentation regarding AsyncLocalStorage.run that states:

This methods runs a function synchronously within a context and return its return value. The store is not accessible outside of the callback function or the asynchronous operations created within the callback.

As far as I can tell this is not true, for example:

const {AsyncLocalStorage} = require('async_hooks');
const storage = new AsyncLocalStorage();

storage.run('anything', () => {
  setTimeout(() => {
    console.log(storage.getStore()); // prints "anything"
  }, 10);
});

I'd consider setTimeout callback to be an asynchronous operation created within the callback and the store is accessible there.

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  submit a pull request

[kjarmicki]

Sorry, I just now realized that I've most likely misinterpreted the docs: I thought they stated that store is not accessible in the asynchronous operations created within the callback, but now I see that it's the opposite, which is consistent with the behavior. Carry on 😅

[lagnat]

I misread that too. Even after reading this report, it still took about a dozen readings before I understood. For any future reader of this ticket, what it's really saying is The store is not accessible outside of the callback function or **outside** the asynchronous operations created within the callback