Accept AsyncIterator as an HTTP request body

[RikkiGibson]

See the article on async iterators: https://jakearchibald.com/2017/async-iterators-and-generators/

This is probably only for nodejs, at least to start with, because browsers don't support streaming request bodies (not even fetch at this point, even though it's in the spec). This is a more modern alternative to the nodejs stream interface.

@bterlson may wish to comment on this

[bterlson]

I support this 100%!!

But why just uint8array? AsyncIterator<string> could be allowed as well?

[RikkiGibson]

I think it could be AsyncIterator<string | ArrayBuffer | ArrayBufferView> without any ill effects.

See the current HttpRequestBody for reference:

ms-rest-js/lib/webResource.ts

Line 12 in fc9d854

export type HttpRequestBody = Blob | string | ArrayBuffer | ArrayBufferView | (() => NodeJS.ReadableStream);

[bterlson]

Yes, sounds excellent.

[ramya-rao-a]

@jeremymeng Is this applicable for the new Azure Core v2? If so, please create a new issue in the azure-sdk-for-js repo and close this issue