Introduction

OneSocket is a simple, lightweight socket server and socket client library written in TypeScript for NodeJS.

Under the hood OneSocket uses:

• NodeJS native net module
• Zod for schema validation
• JSON for data serialization

Installation

npm i -D one-socket

Usage

OneSocket is designed to be used in a microservice architecture as RPC or IPC. In comparison to gRPC and protobuf OneSocket uses JavaScript and JSON which makes it very easy to start working with. OneSocket is not designed to be used in a browser, because it doesn't use HTTP.

Getting Started

Schema

OneSocket uses Zod Schema to parse all incoming and outgoing parameters. The Schema is defined as follows:

 const schema = {
  "-=Method Name=-": {
    request: z.object({
      // incoming object schema
    }),
    response: z.object({
      // outgoing object schema
    }),
  },
}

For example, a simple authorization method's Schema can look like this:

import { z } from 'zod';

const schema = {
  SignUp: {
    request: z.object({
      username: z.string().email().min(5),
      password: z.string().min(8),
    }),
    response: z.object({
      userId: z.number(),
    }),
  },

  SignIn: {
    request: z.object({
      username: z.string().email().min(5),
      password: z.string().min(8),
    }),
    response: z.object({
      access: z.string(),
      refresh: z.string(),
    }),
  },
};

This Schema should be shared between your server and client.

OneSocket Client <> Server communication

OneSocket uses JSON to communicate between client and server. To call a server method the client should send a JSON object with a following structure:

const requestMessage = {
  type: '-=Method Name=-',
  payload: {
    // request object
  },
}

The server will parse the request object using the Schema and call the corresponding handler function. The handler function should return a response object that will be validated using the Schema and sent back to the client with a following structure:

const responseMessage = {
  success: true,
  payload: {
    // response object
  },
} | {
  success: false,
  errorMsg: 'error message'
}

If there has been any error during the request parsing or handling, the server will put the error message into the errorMsg field and set success to false. If the request has been handled successfully, the server will put the response object into the payload field and set success to true.

Handlers

Handlers are defined as an object with method names as keys and handler functions as values. For example:

const SignUp: (params: z.infer<typeof schema.SignUp.request>) => Promise<z.infer<typeof schema.SignUp.response>> = async (params) => {
  // all handler functions should be asynchronios (return a Promise) 
  return Promise.resolve({ 
    userId: 1,
  });
};

const SignIn: (params: z.infer<typeof schema.SignIn.request>) => Promise<z.infer<typeof schema.SignIn.response>> = async (params) => {
  // all handler functions should be asynchronios (return a Promise) 
  return Promise.resolve({
    access: 'access token',
    refresh: 'refresh token',
  });
};

const handlers = {
  SignUp: SignUp,
  SignIn: SignIn,
}

Server instance

Both Schema and Handlers should be supplied to the OneSocket server instance (after the host port).

OneSocketServer(8123, schema, handlers);

Client instance

Client instance is a function that takes a host, port and a JSON object as parameters and returns a promise that resolves to a stringified JSON object.

OneSocketClient('127.0.0.1', 8123, { type: 'SignUp', payload: { username: 'admin', password: '123' } });

Since all requests and responses will be parsed using Zod on the Server, the client can safely infer the response type from the schema and return a typed response.

import { OneSocketClient, type TResponse } from 'one-socket';

// wrapper type
type SignUpResponse = TResponse<z.infer<typeof schema.SignUp.response>>;

const SignUpSend: (params: z.infer<typeof schema.SignUp.request>) => Promise<SignUpResponse> = async (params) => {
  const resp = await OneSocketClient('127.0.0.1', 8123, { type: 'SignUp', payload: params });

  return JSON.parse(resp) as SignUpResponse;
};

Examples

you can find examples under /examples folder

Feature Plans

• Change message format to have proper signature
• Integrate authentication
• Handle binary data
• Add tests
• Add more examples