Encoding objects with oneof and undefined vs null

[SkeLLLa]

protobuf.js version:6.7.3

Here is example proto file that describes message format that could contain one of some Types in body.

syntax = "proto3";

import "Type1.proto";
import "Type2.proto";
import "Type3.proto";
...
import "Type100500.proto";

package pack;

message MyMessage {
    string head = 1;
    oneof body {
        Type1 Type1 = 2;
        Type2 Type2 = 3;
        Type3 Type3 = 4;
...
        Type100500 Type100500 = 1005001;
    }
}

Proto files are compiled into js with pbjs.
Later in typescript:

import * as proto from 'my-static-protobuf-schemas';

const encode(type: string, payload: any): ArrayBuffer {
  const message = proto.pack.MyMessage.create({
      head: 'my-message-header',
      body: type,
      [type]: payload
    } as proto.pack.MyMessage$Properties);
  return proto.pack.MyMessage.encode(message).finish()
}

And here typescript throws error

Error:TS2345:Argument of type 'MyMessage' is not assignable to parameter of type 'MyMessage$Properties'.
  Types of property 'Type1' are incompatible.
    Type 'Type1$Properties | null' is not assignable to type 'Type1$Properties | undefined'.
      Type 'null' is not assignable to type 'Type1$Properties | undefined'.

Should I set to null all 100499 objects or there is some way to do that automatically?

[dcodeIO]

If I'm not mistaken, your encode method should be generic or something.

const encode<T>(type: string, payload: T): ArrayBuffer {
  const message = proto.pack.MyMessage.create({
      head: 'my-message-header',
      body: type,
      [type]: <T>payload
    } as proto.pack.MyMessage$Properties);
  return proto.pack.MyMessage.encode(message).finish()
}

Haven't looked through this in detail, though, as it seems to be a TypeScript usage issue.

[Alexendoo]

It is a typescript/jsdoc issue yeah, it's because the type of an embedded message is IMessage|null rather than IMessage|undefined (or Message$Properties|... for 7.x)

[dcodeIO]

See also: #826