Promisify crashing node (or making it hang) #49607

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1. aduh95 commented on Sep 11, 2023

   

   aduh95

   on Sep 11, 2023

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   Status code 0, process exits.

   That's really surprising, I'm getting exit code 13, can you double check if you're seeing an exit code 0?
2. SamMousa commented on Sep 11, 2023

   

   SamMousa

   on Sep 11, 2023

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   I can, one sec.

   Edit: hmm, you are right, this reproduction is code 13, looking into source repo to see if it might be 13 there as well.
3. SamMousa commented on Sep 11, 2023

   

   SamMousa

   on Sep 11, 2023

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   The same code crashing in the code I linked above (semantic-release/commit-analyzer#525) exits with code 0. I'm no node developer so I'm probably a lot out of my depth here...

   I for sure can't catch whatever error is happening (I tried).

   process.exitCode is probably the culprit of hte crash being silent, so it is crashing node but not silent by default...
4. aduh95 commented on Sep 11, 2023

   

   aduh95

   on Sep 11, 2023

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   Assuming you are seeing an exit code of 13, then it's the expected and documented behavior:
   

   node/doc/api/process.md

   Lines 3929 to 3930 in 718981e

   	* `13` **Unfinished Top-Level Await**: `await` was used outside of a function
   	in the top-level code, but the passed `Promise` never resolved.

   What's happening is that promisify returns a promise which will be resolved once the last argument of asyncFunction is called. Because that never happens, the promise never settles, and the process exits because it has nothing left to do.
   You need to call that last argument, e.g.:

   import { promisify } from "node:util";
   
   
   const asyncFunction = async (callback) => callback(null, 5);
   
   await promisify(asyncFunction)();
   console.log('This does show');

   if you do accept async functions maybe promisify should be a noop since async functions already return promises...

   An async function is indistinguishable from a sync function, I don't think there's a reliable way for the runtime to detect if the passed function is async or not. Maybe a linter could catch it though

   👍React with 👍1Reacted by Vitor L Cavalcanti
5. SamMousa commented on Sep 11, 2023

   

   SamMousa

   on Sep 11, 2023

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   An async function is indistinguishable from a sync function

   .constructor.name allows you to, not sure if it's standard though.

   I'll look a bit further. I'm not sure the mistakes you point out mean there is no bug, or my reproduction is simply wrong...
6. nodejs-github-bot

   closed this as completedin #49609on Sep 18, 2023
7. nodejs-github-bot

   added a commit that references this issue on Sep 18, 2023

   util: runtime deprecate `promisify`-ing a function returning a `Promise`

   ...

   ccca547