prefer-object-has-own.md

Pattern: Use of hasOwnProperty call

Issue: -

Description

Using Object.prototype.hasOwnProperty.call() is a common but verbose way to safely check for object properties. The ES2022 Object.hasOwn() method provides a shorter, clearer alternative that achieves the same goal.

Examples

Example of incorrect code:

Object.prototype.hasOwnProperty.call(obj, "prop");
Object.hasOwnProperty.call(obj, "key");
({}).hasOwnProperty.call(object, "foo");

const hasProp = Object.prototype.hasOwnProperty.call(obj, prop);
if (Object.prototype.hasOwnProperty.call(data, "id")) {}

Example of correct code:

Object.hasOwn(obj, "prop");
Object.hasOwn(object, "foo");

const hasProp = Object.hasOwn(obj, prop);
if (Object.hasOwn(data, "id")) {}

// Direct calls on objects are checked by no-prototype-builtins
if (obj.hasOwnProperty("id")) {}