Invalid typescript syntax generated for google.protobuf.Struct RPC replies in v1.88.0

[mkmarek]

Hi, there seems to be a regression in v1.88.0 when it comes to decoding response data that are google.protobuf.Struct.

I made a small repository to replicate the issue: https://github.com/mkmarek/ts-proto-bug

For a service like this:

service Service {
    rpc Bar (BarRequest) returns (google.protobuf.Struct);
}

there is this kind of typescript code generated:

Bar(
      request: BarRequest
    ): Promise<{[key: string]: any} | undefined> {
      const data = BarRequest.encode(request).finish();
      const promise = this.rpc.request(
        
        "pkg.Service",
        "Bar",
        data
      );
      return promise.then(data => {[key: string]: any} | undefined.decode(new Reader(data)));
    }

the return promise.then(data => {[key: string]: any} | undefined.decode(new Reader(data))); has invalid syntax.

Versions used:

libprotoc 3.0.0
ts-proto v1.88.0

[stephenh]

Ah hrm, @boukeversteegh given this is related to google.protobuf.Struct, wdyt of ^? I can take a look later as well... Thanks for the report @mkmarek !

[boukeversteegh]

Oh yes, I had similar issues in other places. The call-site where the TypeName is resolved assumes that it will always get back a ClassName for 'messages' (not primitives). However, since now we have several message types that don't resolve to class-names by default, you get these breaks.

The fix is easy though, the call to basicTypeName should specify {keepValueType: true}.

I will look tomorrow or wednesday if no-one else would. We probably need a test for this too.

[boukeversteegh]

couldn't help to have a quick look.

the problem is here I think, where responseType() should preserve the original value type, and not convert it to typescript.

normally, grpc services cannot return primitives (i think?), so the assumption makes sense.

ts-proto/src/generate-services.ts

Lines 110 to 116 in c2e6f81

	const outputType = responseType(ctx, methodDesc);
	const params = [...(options.context ? [code`ctx: Context`] : []), code`request: ${inputType}`];
	const maybeCtx = options.context ? 'ctx,' : '';
	let encode = code`${rawInputType}.encode(request).finish()`;
	let decode = code`data => ${outputType}.decode(new ${Reader}(data))`;

[stephenh]

🎉 This issue has been resolved in version 1.90.1 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀