deep clone when there's circlular reference

base.ts

class BaseModel {


  private deepCloneImpl(oldObject: object, intrinsicTypes: string[], clonedMap: WeakMap<object, unknown>){
    if (!oldObject || typeof oldObject !== "object") return oldObject;

    if(clonedMap.has(oldObject)){
      return clonedMap.get(oldObject)
    }

    if (Array.isArray(oldObject)) {
      const newObject: any = [];
      clonedMap.set(oldObject, newObject)
      for (let i = 0, l = oldObject.length; i < l; ++i){
        newObject.push(this.deepCloneImpl(oldObject[i], intrinsicTypes, clonedMap));
      }
      return newObject;
    }

    if (0 <= intrinsicTypes.indexOf(oldObject.constructor.name)) {
      return oldObject;
    }

    const newObject = new Object();
    clonedMap.set(oldObject, newObject)
    for (const key in oldObject) {
      if (key in oldObject) {
        newObject[key] = this.deepCloneImpl(oldObject[key], intrinsicTypes, clonedMap);
      }
    }
    return newObject;
  }

  /**
   * Deep clone
   *
   * @param oldObject
   * @param intrinsicTypes
   */
  deepClone(oldObject: object, intrinsicTypes: string[] | null = null) {
    if (null === intrinsicTypes) {
      if (!("intrinsicTypes" in this.options)) intrinsicTypes = [];
      else if (false === this.options.intrinsicTypes) return oldObject;
      else intrinsicTypes = this.options.intrinsicTypes as string[];
    }
    return this.deepCloneImpl(oldObject, intrinsicTypes, new WeakMap())
  }

}