A simple grpc Wrapper for nodejs

basic-grpc is a small wrapper over grpc and @grpc/proto-loader its goal is to make the implementation very basic with minimal setup.

Usage:

Example proto file

protos/login.proto

  syntax = "proto3";

  package login;

  service Login {
    rpc login (Credentials) returns (Token) {}
  }

  message Credentials {
    string username = 1;
    string password = 2;
  }

  message Token {
    string token = 1;
  }

if you are using typescript you can also create a declaration file:

protos/login.d.ts

  import { rpc } from "simple-grpc";

  export interface ILogin {
    login: rpc<ICredentials, IToken>;
  }

  export interface ICredentials {
    username: string;
    password: string;
  }

  export interface IToken {
    token: string;
  }

Create a service

grpcServer.ts

import { 
  createServer, 
  ISetup,
  IProtoService, 
  RPCError, 
  createServerCreds
} from "simple-grpc";

import { join } from "path";
import { ILogin } from "../protos/login";

const loginService: IProtoService<ILogin> = {
  protoFile: "login.proto", // the .proto fileName
  packageName: "login", // packageName (what is defined in the .proto file as package)
  serviceName: "Login",  // serviceName (what is defined in the .proto file as Service)
  handlers: { // the function handlers for every rpc call
    login: async ({ username, password }) => {
      if(password === "awesomeSecretPassword") 
        return  {
          token: generateToken(username)
        };
        
      // you can throw an RPCError  with a code and details for the error 
      // the first 15 are gRPC generic you can add custom errors from 15+
      // see: https://github.com/grpc/grpc/blob/master/doc/statuscodes.md
      throw new RPCError(22, "Invalid Credentials");
    }
  },
};

const gRPCSetup: ISetup = {
  protoRoot: join(__dirname, "..", "protos"), // root folder where all your .proto files live
  services: [ // a list of services for this particular server
    loginService
  ]
};

// options for the protoloader
const protoLoaderOptions = {
  keepCase: true,
  longs: String,
  enums: String,
  defaults: true,
  oneofs: true
};

// the host of your gRPC server
const domain = "localhost:50051";

// accepts and array of Buffers or strings (truple) [ rootCerts, cert_chain, private_key ] 
// or it can create an insecure connection if nothing is passed
const credentials = createServerCreds();

// returns a gRPC server instance 
const server = createServer({
  gRPCSetup,
  domain,
  options: protoLoaderOptions, // if not passed it will use the default values
  credentials, // if not passed it will create an insecure connection
});

// starts the server :)
server.start();
console.log("Server Started");

Create a client

client.ts

import { createClient, createClientCreds } from "simple-grpc";
import { ILogin } from "../protos/login";
import { join } from "path";

const protoLoaderOptions = {
  keepCase: true,
  longs: String,
  enums: String,
  defaults: true,
  oneofs: true
};

// accepts and array of Buffers or strings (truple) [ rootCerts, cert_chain, private_key ] 
// or it can create an insecure connection if nothing is passed
const credentials = createClientCreds();

const loginService = createClient<ILogin>({
  url: "localhost", // url of the gRPC Server 
  port: "50051", // port of the gRPC server 
  protoPath: join(__dirname, ".." , "protos", "login.proto"), // root folder of your .protoFiles
  packageName: "login",  // packageName (what is defined in the .proto file as package)
  serviceName: "Login", // serviceName (what is defined in the .proto file as Service)
  options: protoLoaderOptions, // if not passed it will use the default values
  credentials, // if not passed it will create an insecure connection
  calls: [ "login" ] // the available rpc calls to that service defined in the .proto file
});


try {
  // you can then call the login function for the loginService :)
  // it will return a promise with the data or it Will throw an RPCError with code and details.
  const data = await loginService.login({ username: "JohnDoe", password: "awesomeSecretPassword" });
  console.log(JSON.stringify(data, undefined, 2));
} catch ({ code, details }) {
  console.log("ERR", code, details);
}

check this repo for an example: https://github.com/Flaavius/basic-grpc-example