I am developing a program with Angular and TypeScript. I have a class called Signal, which has the next parameters:

export class Signal {
    id: number;
    obraId: number;
    obra: string;
    descripcion: string;
    rangoInferior: string;
    rangoSuperior: string;
    unidades: string;
    // more parameters

    // I use ofJson method to create a Signal object
    static ofJson(signalJson: ISignalJson): Signal {
        return this.createSignal(signalJson.id, signalJson.obraId, signalJson.obra, 
            signalJson.descripcion, signalJson.rangoInferior, signalJson.rangoSuperior,
            signalJson.unidades
        );
    }

    static createSignal(id: number, obraId: number, obra: string,descripcion: string, rangoInferior: string, rangoSuperior: string,
        unidades: string
    ): Signal {
        const new_signal = new Signal();
        new_signal.id = id;
        new_signal.obraId = obraId;
        new_signal.obra = obra;
        new_signal.descripcion = descripcion;
        new_signal.rangoInferior = rangoInferior;
        new_signal.rangoSuperior = rangoSuperior;
        new_signal.unidades = unidades;
        return new_signal;
    }
}

When I get the data from API, some parameters (descripcion, rangoInferior, rangoSuperior) has null value and I want to set to empty string. To get this, I use private properties and getters/setters.

Example:

    private _descripcion: string;
    public get descripcion(): string {
        return this._descripcion;
    }
    public set descripcion(value: string) {
        this._descripcion = value ? value : "";
    }

The problem is that this object send with underscores fields to API and return an error.

{
  "_descripcion": "lll5",
  "id": 621284,
  "obra": "INTEGRATION-TESTS",
  "obraId": 378,
  "_rangoInferior": '',
  "_rangoSuperior": '',
  "_unidades": ''
}

I have seen several answers to solve this:

• Make a toJson method and remove the underscores.
• Use Object.defineProperties as below:

  Object.defineProperties(this,
          {
              _descripcion: { writable: true, enumerable: false },
              descripcion: {
                  get() { return this._descripcion; },
                  set(value: string) { this._descripcion = value ? value : ""; },
                  enumerable: true
              }
          }
      );
  

• Which is the best solution?
• Is there another answer which I should considerate?