How do I access the Object.prototype method in the following logic?

Question

I am using the following logic to get the i18n string of the given key.

export function i18n(key) {
  if (entries.hasOwnProperty(key)) {
    return entries[key];
  } else if (typeof (Canadarm) !== 'undefined') {
    try {
      throw Error();
    } catch (e) {
      Canadarm.error(entries['dataBuildI18nString'] + key, e);
    }
  }
  return entries[key];
}

I am using ESLint in my project. I am getting the following error:

Do not access Object.prototype method 'hasOwnProperty' from target object. It is a 'no-prototype-builtins' error.

How do I change my code to resolve this error ? I don't want to disable this rule.

Answer 1

You can access it via Object.prototype:

Object.prototype.hasOwnProperty.call(obj, prop);

That should be safer, because

• Not all objects inherit from Object.prototype
• Even for objects which inherit from Object.prototype, the hasOwnProperty method could be shadowed by something else.

Of course, the code above assumes that

• The global Object has not been shadowed or redefined
• The native Object.prototype.hasOwnProperty has not been redefined
• No call own property has been added to Object.prototype.hasOwnProperty
• The native Function.prototype.call has not been redefined

If any of these does not hold, attempting to code in a safer way, you could have broken your code!

Another approach which does not need call would be

!!Object.getOwnPropertyDescriptor(obj, prop);