grpc-web VS ts-proto

* Additionally, client can stream data to the backend server (if bidirectional GRPC streams are used). I.e. client sends WebSocket messages, those will be transformed to GRPC messages by WebSocket server and delivered to the application backend.

As a result we have a system which allows to quickly create individual streams by using strict GRPC contract but terminating connections over WebSocket transport. So it works well in web browsers. After that no need to write WebSocket protocol, client implementation, handle WebSocket connection. This all will be solved by a suggested WebSocket server and its client SDKs.

The mechanics is similar to Websocketd (https://github.com/joewalnes/websocketd), but instead of creating OS processes we create GRPC streams. The difference from grpc-web (https://github.com/grpc/grpc-web) is that we provide streaming capabilities but not exposing GRPC contract to the client - just allowing to stream any data as payload (both binary and text) with some wrappers from our client SDKs side for managing subscriptions. I.e. it's not native GRPC streams on the client side - we expose just Connection/Subscription object to stream in both directions. GRPC streams used only for communication between WebSocket server and backend. To mention - grpc-web does not support all kinds of streaming now (https://github.com/grpc/grpc-web#streaming-support) while proposed solution can. This all should provide a cross-platform way to quickly write streaming apps due to client SDKs and language-agnostic nature of GRPC.

I personally see both pros and cons in this scheme (without concentrating on both too much here to keep the question short). I spent some time thinking about this myself, already have some working prototypes – but turned out need more opinions before moving forward with the idea and releasing this, kinda lost in doubts.

My main question - whether this seems interesting for someone here? Do you find this useful and see practical value?

By default, web browsers do not support gRPC, but we will use gRPC-web to make it possible.

You just have to use a library implementation for JavaScript https://github.com/grpc/grpc-web

TypeScript support remains an experimental feature of gRPC.

The gRPC-Web protocol supports HTTP/1 and can be used from a browser.

-- grpc-web

gRPC is mainly used in server-to-server communication, but it can also be used in client-to-server communication. gRPC-web is a gRPC implementation for web browsers. It is a JavaScript library that allows you to call gRPC services from a web browser. It supports Unary and Streaming Server API calls.

Since we're using Envoy, there's one more neat trick that we can employ. It turns out that Envoy also support gRPC-Web out of the box, a JavaScript client designed to support gRPC communication from the browser! That means that we can send gRPC messages over HTTP/1.1 as base64 encoded strings or as binary protobufs. Messages will be sent through our proxy and on to our backend service. The advantage of this is smaller and more efficient wire communication which should lead to better performance.

protoc-gen-grpc-web — a plugin that allows our front end to communicate with the backend using gRPC calls. A separate blog post on this coming up in the future.

I created it so that I could use `protoc` and `ts-proto` to convert the otel proto files into typescript files.

Re libraries incompatible with certain typescript versions - e.g. protobufjs fix - it’s been my experience that you want to try and only use compilers specific to each library and compile libraries separately. It’s unfortunate but the JS community often tries to run all JS for a project through the same single compiler tool chain, using one global version of the compiler instead of relying on and effectively linking the JS output for each library. Unless you routinely rewrite third-party libraries to match your toolchain’s expectations, you’re going to have a hard time doing that.

For a library that generates code, that’s a special case, as the code it generates must target a particular language version. You have three choices: 1. Upstream a fix as you propose; 2. Side-by-side install both TS 4.6 and TS 4.7 using workspaces or sub-projects and have some of your code compile with 4.6 and then link the results or 3. Find a replacement that is updated to 4.7. For example, https://github.com/stephenh/ts-proto has 4.7 support listed in its readme.

With ts-proto, I can pass a --ts_proto_opt=outputServices=generic-definitions as a flag to protoc to generate "generic service definitions". These definitions contain descriptors for each method, which allows to generate server and client stubs at runtime, and also generate strong types for them at compile time.

Curious to see their typescript implementation and how it compares with https://github.com/stephenh/ts-proto which works great for grpc-web.

I'm planning on modding https://github.com/stephenh/ts-proto to use https://github.com/ianstormtaylor/superstruct on the client.

We also use protobufs and typescript, so we use ts-proto for codegen + binding to grpc services.

Fwiw I maintain ts-proto (https://github.com/stephenh/ts-proto/) and it'd be cool to have the functionality you're building supported in ts-proto at somepoint, if you're curious/want to poke around/etc. :-) Right now there is grpc support via the improbable-eng grpcwebproxy, but supporting GCP's transcoding as well would be great.