Why there is not Body.prototype.getReader API？

[manooog]

As we can see, Body is sub of Stream,which has getReader API,see below:

https://streams.spec.whatwg.org/#ref-for-rs-get-reader%E2%91%A4

So, why node-fetch not implement the same interface?

[jimmywarting]

node-fetch was create long before web streams where introduced into NodeJS, and most node api used node:streams anyways which lead to us not simply using it. so we compromised a bit cuz most ppl would just convert it into a node:stream anyway to use it along with node:fs and other things.

Now this have changed. web streams have been introduced into NodeJS, more and more api's accept Uint8Array and async iterators now instead. So a async iterable web stream can be written to the disc without conversion back into a node:stream and then being piped to.

Now we could switch to using web streams, and those who still need node:streams could use streams.Readable.from(iterable)
but that would be a very large breaking change for many ppl who depend on node-fetch today.

but the opposite is also possible to do using stream.Readable.toWeb(response.body) but it also quite very new-ish. and we still need to support older LTS version that don't have this new capabilities today. We could introduce a new breaking change but then again, we could just now recommend that ppl just switch to using the new built-in fetch api provided by NodeJS themself now from v18+
the built in is based on web stream and follows the fetch specification more correctly.
so our recommendation is to use the built in fetch in v18
if you do want to use it in v16 then you would have to depend on undici directly instead. That's the official fetch api that's implemented in NodeJS today.

[manooog]

Thanks for your reply!