protobuf.js

import { IMemberRemarkedA, IMemberRemarkedB, MemberRemarkedA, MemberRemarkedB} from './compiled/index.js'

// both messages have same values
let userACreatePostMsg: IMemberRemarkedA =  {
    createPost: {
        threadId: 1,
        body: "some text"
    }
}

let userBCreateCommentMsg: IMemberRemarkedB =  {
    createComment: {
        videoId: 1,
        body: "some text"
    }
}

// simple msg validation, can be improved
const userAMsgError = MemberRemarkedA.verify(userACreatePostMsg)
const userBMsgError = MemberRemarkedB.verify(userBCreateCommentMsg)
if (!userAMsgError || !userBMsgError){
    throw new Error(userAMsgError+ "; "+ userBMsgError)
}

const encodedCreatePostMsg = MemberRemarkedA.encode(userACreatePostMsg).finish()
//  Serialized message:   5a0d08011209736f6d652074657874
//               |   5a    |0d08011209736f6d652074657874|
//               |field no.|          message           |
const encodedCreateCommentMsg = MemberRemarkedB.encode(userBCreateCommentMsg).finish()
//  Serialized message: aa010d08011209736f6d652074657874
//               |  aa01   |0d08011209736f6d652074657874|
//               |field no.|          message           |

// Notice the `message` parts of both serialized payloads are same since the values are same


// Scenario 1: User A deserializing his own message i.e. CreatePost 
const userADecodesCreatePostMsg = MemberRemarkedA.decode(encodedCreatePostMsg)
console.log(userADecodesCreatePostMsg)
/**
 * Result:  
 * createPost: CreatePost {
 *  threadId: 1,
 *  body: 'some text'
 * }
 */


// Scenario 2: User A deserializing message unknown to him, e.g. CreateComment
const userADecodesCreateCommenttMsg = MemberRemarkedA.decode(encodedCreateCommentMsg)
console.log(userADecodesCreateCommenttMsg)
/**
 * Result: {}
 */


// Scenario 3: User B deserialing his own message i.e. CreateComment
const userBDecodesCreateCommentMsg = MemberRemarkedB.decode(encodedCreateCommentMsg)
console.log(userBDecodesCreateCommentMsg)
/**
 * Result:   
 * createComment: CreateComment {
 *  videoId: 1,
 *  body: 'some text'
 * }
 */


// Scenario 4: User B deserializing message unknown to him, e.g. CreatePost
const userBDecodesCreatePostMsg = MemberRemarkedB.decode(encodedCreatePostMsg)
console.log(userBDecodesCreatePostMsg)
/**
 * Result: {}
 */