NestJs - CQRS - Looking for a simple way to pass an object as constructor parameters (From a DTO to a command)

I would like to initialize a Command as Follows:

const command = new CreateProductCommand(payload);

// In another file
export class Payload {
    public readonly type: string;
    public readonly name?: string;
}

where my Command is defined like this:

export class CreateProductTypeACommand {
    public readonly name?: string;
}

I have tried create an abstract command to do this in the constructor:

export class AbstractCommand<T> implements ICommand {
    constructor(args: T) {
        Object.assign(this, args);
    }
}

// in another file
export class CreateProductTypeACommand extends AbstractCommand<CreateProductTypeACommand> {
    public readonly name?: string;
}

But this dosen't work: the child's constructor overrides the parents and the value for name gets overridden by undefined . Also the object ends up having the type field.

Any idea? I would rather not put any boiler plate code in my command classes or define a CreateProductTypeACommandArgs type.

I had a similar problem and what I ended up doing was using plainToClass from the class-transformer package.

For example

import { ClassConstructor, plainToClass } from "class-transformer";

// A neat utility function to check you supply all class properties
function map<T, V extends T>(cls: ClassConstructor<T>, plain: V): T {
  return plainToClass(cls, plain);
}

function doStuff() {
      const newProfile = {
        description: "my-description",
        name: "my-name",
        recentLocation: { lat: 1, lon: 2 },
        userId: "my-user-id",
      };

      const command = map(CreateProfileCommand, newProfile);
      ...
}