jcayzac•7mo ago

Abort signals and node compatibility

Deno and Node's AbortSignal types are not compatible. I have verified that I can use a deno AbortSignal with the node:events APIs (at least EventEmitter.once(), but I have to cast them to Node's own type if I want to get rid of errors:

export { EventEmitter } from 'node:events'
export type { AbortSignal as NodeAbortSignal } from 'npm:@types/node'

// …then cast any signal to `signal as NodeAbortSignal`.

export { EventEmitter } from 'node:events'
export type { AbortSignal as NodeAbortSignal } from 'npm:@types/node'

// …then cast any signal to `signal as NodeAbortSignal`.

Without the cast, I get the error below. Is there a better/cleaner way? Thanks.

3 Replies

Deno AI Helper•7mo ago

I wasn't able to find the answer to your question in the official Deno documentation. However, based on the code snippet you've provided, it seems like you are trying to integrate Deno's AbortSignal with Node's EventEmitter from the node:events module. From what you've described, it appears that you are encountering type compatibility issues between Deno and Node's AbortSignal types. Your current workaround involves casting the Deno AbortSignal to the Node type to avoid type errors. While I cannot provide a solution based on the Deno documentation, I can confirm that your approach of casting types is a common workaround when dealing with type incompatibilities in TypeScript. However, please note that this advice is not based on the Deno documentation, and you should double-check the accuracy of this advice. If you are looking for a cleaner way to handle this, you might want to consider creating a utility function or a wrapper that handles the casting for you, so you don't have to manually cast each time you use the AbortSignal with Node's EventEmitter. This could encapsulate the type casting logic in one place and make your codebase cleaner. Remember to keep an eye on the Deno and Node.js release notes for any updates that might address this compatibility issue in the future.

Helpful Links: node: specifiers | Deno Docs Deno 1.16 Release Notes How to publish Deno modules to NPM Deno 1.4 Release Notes

marvinh.•7mo ago

Can you file an issue for that on the deno repository? This is something that should work imo

jcayzac•7mo ago

@marvinh. done: https://github.com/denoland/deno/issues/21860

GitHub

Deno's AbortSignal type isn't compatible with Node APIs · Issue #21...

Version: Deno 1.39.1 I have verified that I can use a deno AbortSignal with the node:events APIs (at least with EventEmitter.once(), but I have to cast them to Node's own type if I want to get ...