Remove web-streams-polyfill and abort controller polyfill

[jacoblee93]

Fixes #613

[jacoblee93]

I added "lib": ["DOM"], to the tsconfig.json file to fix typing, and also removed the AbortController polyfill (this has been supported in Node since version 15: https://developer.mozilla.org/en-US/docs/Web/API/AbortController#browser_compatibility)

I was able to set up tests via the OpenAPI spec, seems like there's a few unrelated errors:

This is a bit bigger of a change than initially planned, but should be supported by all LTS Node versions. You can also add special instructions for people to polyfill Node 16 like this if you're very worried:

https://js.langchain.com/docs/get_started/installation#unsupported-nodejs-16

LMK what you think!

[jacoblee93]

May also be worth removing node-fetch since native fetch is now in Node 18 to avoid weird bundler issues, but that would be another PR.

[rattrayalex]

May also be worth removing node-fetch since native fetch is now in Node 18 to avoid weird bundler issues, but that would be another PR.

It is indeed: #402

[rattrayalex]

Thank you Jacob!

Will need to have a member of our team review more thoroughly, but first will need to resolve question around DOM

[rattrayalex]

ah, sadly I don't think this is an acceptable change b/c we don't want to drag DOM types into our users' projects if they are in a Node setting. Do you remember why it was needed?

[jacoblee93]

ReadableStream isn't defined in the base typing - let me see if I can find another workaround.

[rattrayalex]

BTW why is this only a partial fix?

[jacoblee93]

BTW why is this only a partial fix?

Ah sorry that's a typo, another PR I did for LangChain.js was a partial fix for some typing issues we were seeing and I think my mind was on that.

[jacoblee93]

With some light Googling, it seems that the only way to get the ReadableStream type without getting hacky and potentially causing more issues seems to be to include DOM in tsconfig.json.

We've been doing it upstream in LangChain.js for a while now with (seemingly) good compatibility:

https://github.com/langchain-ai/langchainjs/blob/main/langchain/tsconfig.json#L10

But if we don't feel comfortable doing that here, then perhaps it's best to hope for a good downstream resolution here and bump the polyfill later on:

MattiasBuelens/web-streams-polyfill#141

[rattrayalex]

K, then yes that might be best… 

Is ReadableStream in the node types?

If so, maybe we want to reexport from our node and web shims, rather than remove it?

[jacoblee93]

This has been fixed in the downstream polyfill - feel free to close this!

MattiasBuelens/web-streams-polyfill#142