Javascript and/or web support

[zeebo]

A commonly requested language is javascript. I haven't used gRPC with javascript before, so I don't know much about use cases, so here's some questions:

1. Is server support desired?
2. Is bi-directional streaming support desired?
3. Does gRPC currently do bi-directional streaming?
4. Is it targeting being run in a browser or is that "web" which is distinct from "javascript" and/or "node"?
5. There's an example that shows how to serve both http and raw sockets on the same port, but only handles unitary http requests with json. Would that be sufficient server side support?

This issue is meant to collect information about use cases people have and potential answers to the above questions.

[alecthomas]

My 2c is that unless your goal is to expose the DRPC service using Google's HTTP annotations, I'd go for full feature compatibility and use WebSockets (or whatever the latest hotness is).

[mjpitz]

I managed to get a little done for the wire format for NodeJS here: https://github.com/mjpitz/drpc-node

I'm mostly following the Golang implementation, but I've also been popping over to the wiki as I write it to see how much aligns.

[mjpitz]

@zeebo per your comment on #7, is it ok that the node library is written in typescript? I don't mind swapping, but it's just my preference since it makes reasoning about types a bit easier.

[zeebo]

Yeah, that's totally fine. I prefer typescript as well, but most importantly since you're writing it you get to choose those sorts of things.

[egonelbre]

I think it was possible to use TypeScript code from JavaScript, so I don't think it makes a big difference.

[mjpitz]

Alright. @zeebo I wrapped up the last of the drpcwire package in Node. There's one bug right now where I reset the ID after successfully processing a packet, but that's an easy fix. I've updated the wiki on the wire protocol to describe the frame format a bit more and even included a section on assembling packets. Not sure what the best way to collab on wiki pages in GitHub are or if you have any preference. Anyway, I'll probably start in on the drpcstream package next.

[timostamm]

Hey there, I wrote a protoc-plugin and protobuf runtime that supports gRPCweb and Twirp in the browser and node.

Generated clients delegate work to a facade, so it is relatively easy to implement protocols. For example, adapting gRPC is about 300 loc.

This might save you the trouble of writing a protoc plugin to generate clients. HTH

[mjpitz]

Made some good progress on this during a rainy Sunday. I've got what looks like a possibly workable socket layer? When I've got some time, I'll throw together a directory with an interop test that spins up a go server and tries to use node to communicate with it via the wire protocol (and vice-versa). It would be great to get some eyes on the socket and stream layer just to make sure it looks right from an authors' perspective.

Here's a PR I have up with the proposed socket package: https://github.com/mjpitz/drpc-node/pull/4/files

There are two files in there (stream.ts and a socket.ts) with the bulk of the packet handling and state machine logic that I'd love an extra set of eyes on just to make sure I'm not missing anything.

[frederikhors]

Do you think we can use https://github.com/improbable-eng/grpc-web/tree/master/go/grpcweb with drpc?

If yes with the work @timostamm did (https://github.com/timostamm/protobuf-ts) we are ready for web clients!

[zeebo]

So I tried to make https://pkg.go.dev/storj.io/drpc/drpchttp somewhat follow what I thought Twirp does, but I haven't done any testing to make sure. That may already work if you don't need client streaming. I wonder how hard it would be to extend that package to also serve grpc-web style.

edit: I have a change out at https://review.dev.storj.io/c/storj/drpc/+/5264 that should ensure that drpchttp is compatible with twirp clients going forward.

[frederikhors]

Amazing. Is this released?

[zeebo]

I pushed it up as the exp/twirp-compat branch so you can experiment with it until it's been reviewed and merged onto main. Using go get storj.io/drpc@exp/twirp-compat should be all that's needed to use it with Go modules. It is now merged onto main.

I've also made progress on having drpchttp also serve grpc-web compatible requests/responses, but it's a little bit gross. I'm going to work on finding some ways to clean it up first.

[frederikhors]

I've also made progress on having drpchttp also serve grpc-web compatible requests/responses, but it's a little bit gross. I'm going to work on finding some ways to clean it up first.

Did you get a cue from https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-WEB.md?