fs: add support for async iterators to fs.writeFile

[yagipy]

After this lands, does it make sense to add this to the regular fs version as well (not just fs/promises)?
#37490 (comment)

I'm curious too, so I made it an issue.
If necessary, I would like to handle it.

[aduh95]

If #37948 lands, I think we shouldn't add features to the callback API.
And even if it doesn't land, I would advice to focus on other part of the codebase that needs improvement: users who want to use async iterators with a callback API can use util.callbackify. That being said, I wouldn't block if a PR was sent with an implementation, I just don't think it's necessary.

[benjamingr]

I would be +1 and would be happy to help you collaborate on this regardless of the callback APIs status of legacy yes/no.

It would probably make sense for consistency IMO.

[jimmywarting]

if the async iterator is able to write plain uint8array instead of relying on the buffer, then yes +1

[benjamingr]

@jimmywarting are there any FS APIs that require Buffers and don't take "regular" Uint8Arrays?

[jimmywarting]

@benjamingr Hmm, maybe in the old days, things might have changed for the better now :)

remember that i could write a uint8array cuz it wasn't a buffer - this seems to no longer be the case