Object.hasOwnProperty() yields the ESLint 'no-prototype-builtins' error: how to fix?

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.

You should probably read the docs. There are examples of *correct* code ~ http://eslint.org/docs/rules/no-prototype-builtins — Phil, Sep 02 '16 at 01:01
The code is working fine. This is a linting error. I just want to modify the syntax so that the linting rule is satisfied. — booYah, Sep 02 '16 at 01:04
@passion That will stringify `entries`, ignore `key`, and check if `Object` has a property with that string. — Oriol, Sep 02 '16 at 01:21

score 428 · Answer 1 · answered Sep 02 '16 at 01:17

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);

You save my day, i have to refactor old code from my friend and have to replace so many line of code — Jamviet.com, Jul 29 '22 at 19:22
If you're going to be cautious enough to use `Object.getOwnPropertyDescriptor` then it would definitely be preferable to use an explicit cast with `Boolean()`. — limeandcoconut, May 22 '23 at 20:39

Zameer Ansari · Answer 2 · 2018-07-03T09:40:36.617

54

For your specific case, the following examples shall work:

if(Object.prototype.hasOwnProperty.call(entries, "key")) {
    //rest of the code
}

OR

if(Object.prototype.isPrototypeOf.call(entries, key)) {
    //rest of the code
}

OR

if({}.propertyIsEnumerable.call(entries, "key")) {
    //rest of the code
}

edited Jul 03 '18 at 09:40

answered Jul 03 '18 at 06:53

Zameer Ansari

28,977
24
140
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1

The last example(propertyIsEnumerable) works for me thanks – ho-s Dec 21 '21 at 02:40

score 27 · Answer 3 · answered Jul 07 '22 at 09:43

27

You can use Object.hasOwn(entries, key) instead. hasOwn is intended to be a replacement for Object.hasOwnProperty.

answered Jul 07 '22 at 09:43

Noslac

446
4
5

1

This is the way to go in 2022. It has good browser support, is shorter and easier to remember than the accepted answer, and solves the problem ESLint is complaining about. MDN says, `Note: Object.hasOwn() is intended as a replacement for Object.hasOwnProperty().` See https://tomdn.com?object.hasOwn. – salsbury Aug 19 '22 at 15:20
I see that hasOwn() is supposed to work, but it doesn't seem to be supported in Node v18.10.0. – aikimcr Nov 12 '22 at 00:04

score 19 · Answer 4 · answered Sep 02 '16 at 19:15

19

It seems like this would also work:

key in entries

since that will return a boolean on whether or not the key exists inside the object?

answered Sep 02 '16 at 19:15

Mike Mathew

866
1
7
12

13

`hasOwnProperty` checks if a string or symbol is an own property. `key in entries` checks if it's an own or inherited one. – Oriol Sep 03 '16 at 23:33

score 13 · Answer 5 · answered Nov 09 '21 at 19:16

13

@Orial answer is correct

Use this:

Object.prototype.hasOwnProperty.call(object, "objectProperty");

answered Nov 09 '21 at 19:16

Archil Labadze

4,049
4
25
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3

oof. that is not elegant.... – Shayne Dec 15 '22 at 12:23
2

@Shayne write elegant please ) – Archil Labadze Dec 16 '22 at 10:22
2

No Im not saying the post is inelegant, just the API is inelegant lol – Shayne Dec 19 '22 at 05:33
@Shayne ah got it, yes agree, it's bit uncomfortable ) – Archil Labadze Dec 27 '22 at 08:50

score 2 · Answer 6 · answered Apr 11 '23 at 18:29

To make code more elegant it can be in form a polyfill:

if (!Object.hasOwn) {
    Object.prototype.hasOwn = function (object, property) {
        return Object.prototype.hasOwnProperty.call(object, property);
    }
}

console.log(Object.hasOwn({test: 1}, 'test'), Object.hasOwn({tes: 1}, 'test'))

Mohammed Al-Reai · Answer 7 · 2021-11-04T09:13:57.540

0

this is working for me so try with it

let  bug={
 name:"test"
   }
if (bug && typeof bug === 'object' && Object.prototype.hasOwnProperty.call(bug, name)) {

}

edited Nov 04 '21 at 09:13

answered Oct 03 '21 at 09:18

Mohammed Al-Reai

2,344
14
18

ok, I do that thank you for telling me – Mohammed Al-Reai Nov 04 '21 at 09:14

Object.hasOwnProperty() yields the ESLint 'no-prototype-builtins' error: how to fix?

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