How do you generate typings for protobuf files for use with GRPC? - node.js

Question

I am trying to use GRPC with TypeScript, and I am trying to make sure I have all the types set (rather than just adding my own mapping or using any.
I've gotten as far as with problems I am experiencing noted in the comments.
import { Server, loadPackageDefinition } from "grpc";
import { loadSync } from "#grpc/proto-loader";
const packageDefinition = loadSync(__dirname + "/protos/artifact.proto");
const artifacts = loadPackageDefinition(packageDefinition).artifacts;
// what are the types here?
function SignedUrlPutObject(call, callback) {
}
const server = new Server();
// There's no ArtifactUpload defined in artifacts
server.addService(artifacts.ArtifactUpload.service, { SignedUrlPutObject })
Another approach I tried was to use pbjs and pbts.
"protobuf": "pbjs -t static-module -w commonjs -o protos.js protos/artifact-upload.proto && pbts -o protos.d.ts protos.js",
This generated the typings file, but I can't get it to work with grpc. Here's a github issue I found that may be related https://github.com/protobufjs/protobuf.js/issues/1381

Answer 1

There's 3 main tools you can use:
ts-protoc-gen
#grpc/proto-loader
grpc_tools_node_protoc_ts
I recommend using proto-loader:
npm i #grpc/proto-loader
You can then generate the types like so:
./node_modules/.bin/proto-loader-gen-types --longs=String --enums=String --defaults --oneofs --grpcLib=#grpc/grpc-js --outDir=proto/ proto/*.proto
Here's the proto file I use for this example:
syntax = "proto3";
package example_package;
message ServerMessage {
string server_message = 1;
}
message ClientMessage {
string client_message = 1;
}
service Example {
rpc unaryCall(ClientMessage) returns (ServerMessage) {}
rpc serverStreamingCall(ClientMessage) returns (stream ServerMessage) {}
rpc clientStreamingCall(stream ClientMessage) returns (ServerMessage) {}
rpc bidirectionalStreamingCall(stream ClientMessage) returns (stream ServerMessage) {}
}
Once the types are generated, you can consume them like so:
import * as grpc from '#grpc/grpc-js';
import * as protoLoader from '#grpc/proto-loader';
import { ProtoGrpcType } from './proto/example';
import { ClientMessage } from './proto/example_package/ClientMessage';
import { ExampleHandlers } from './proto/example_package/Example';
import { ServerMessage } from './proto/example_package/ServerMessage';
const host = '0.0.0.0:9090';
const exampleServer: ExampleHandlers = {
unaryCall(
call: grpc.ServerUnaryCall<ClientMessage, ServerMessage>,
callback: grpc.sendUnaryData<ServerMessage>
) {
if (call.request) {
console.log(`(server) Got client message: ${call.request.clientMessage}`);
}
callback(null, {
serverMessage: 'Message from server',
});
},
serverStreamingCall(
call: grpc.ServerWritableStream<ClientMessage, ServerMessage>
) {
call.write({
serverMessage: 'Message from server',
});
},
clientStreamingCall(
call: grpc.ServerReadableStream<ClientMessage, ServerMessage>
) {
call.on('data', (clientMessage: ClientMessage) => {
console.log(
`(server) Got client message: ${clientMessage.clientMessage}`
);
});
},
bidirectionalStreamingCall(
call: grpc.ServerDuplexStream<ClientMessage, ServerMessage>
) {
call.write({
serverMessage: 'Message from server',
});
call.on('data', (clientMessage: ClientMessage) => {
console.log(
`(server) Got client message: ${clientMessage.clientMessage}`
);
});
},
};
function getServer(): grpc.Server {
const packageDefinition = protoLoader.loadSync('./proto/example.proto');
const proto = (grpc.loadPackageDefinition(
packageDefinition
) as unknown) as ProtoGrpcType;
const server = new grpc.Server();
server.addService(proto.example_package.Example.service, exampleServer);
return server;
}
if (require.main === module) {
const server = getServer();
server.bindAsync(
host,
grpc.ServerCredentials.createInsecure(),
(err: Error | null, port: number) => {
if (err) {
console.error(`Server error: ${err.message}`);
} else {
console.log(`Server bound on port: ${port}`);
server.start();
}
}
);
}
I've created various examples of how to use gRPC with TypeScript here: https://github.com/badsyntax/grpc-js-types