grpc-webを使って.protoファイルからWEBブラウザ用JSコードを自動生成する

brew install protobuf
protoc --version

sudo mv ~/Downloads/protoc-gen-grpc-web-1.0.3-darwin-x86_64 /usr/local/bin/protoc-gen-grpc-web
chmod +x /usr/local/bin/protoc-gen-grpc-web

syntax = "proto3";
package helloworld;
service Greeter {
  rpc SayHello (HelloRequest) returns (HelloReply);
}
message HelloRequest {
  string name = 1;
}
message HelloReply {
  string message = 1;
}

protoc -I=./ helloworld.proto \
--js_out=import_style=commonjs:./ \
--grpc-web_out=import_style=commonjs,mode=grpcwebtext:./

import helloworld from './helloworld_grpc_web_pb'

const greeter = new helloworld.GreeterPromiseClient('http://localhost:50051')
const req = new helloworld.HelloRequest()
req.setName('World')
greeter
  .sayHello(req)
  .then((res)=>console.log(res))
  .catch((err)=>console.error(err))