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/** * @name objectProperty * @summary Assign a get property on the input object */export function objectProperty <S> (that: object, key: string, getter: (key: string, index: number, self: S) => unknown, getName?: (key: string, index: number) => string, index = 0): void {  const name = getName    ? getName(key, index)    : key;
  // There are 3 approaches here -  //  - Object.prototype.hasOwnProperty.call(that, key) - this only checks the current class, i.e  //    will retuirn false if the property is set in the parent class  //  - isUndefined(...) - this may yield a false positive when the property is there, but not set.  //    Additionally, on pre-defined getters it may make a call  //  - key in that - Does not need to be combined with either of the above and checks the full chain  if (!(name in that)) {    Object.defineProperty(that, name, {      enumerable: true,      // Unlike in lazy, we always call into the upper function, i.e. this method      // does not cache old values (it is expected to be used for dynamic values)      get: function (): unknown {        return getter(key, index, this as S);      }    });  }}
/** * @name objectProperties * @summary Assign get properties on the input object */export function objectProperties <S> (that: object, keys: string[], getter: (key: string, index: number, self: S) => unknown, getName?: (key: string, index: number) => string): void {  for (let i = 0; i < keys.length; i++) {    objectProperty(that, keys[i], getter, getName, i);  }}