eslint/prefer-object-has-own Style

What it does

Disallow use of Object.prototype.hasOwnProperty.call() and prefer use of Object.hasOwn()

Why is this bad?

It is very common to write code like:

if (Object.prototype.hasOwnProperty.call(object, "foo")) {
  console.log("has property foo");
}

This is a common practice because methods on Object.prototype can sometimes be unavailable or redefined (see the no-prototype-builtins rule). Introduced in ES2022, Object.hasOwn() is a shorter alternative to Object.prototype.hasOwnProperty.call():

if (Object.hasOwn(object, "foo")) {
  console.log("has property foo");
}

Examples

Examples of incorrect code for this rule:

Object.prototype.hasOwnProperty.call(obj, "a");
Object.hasOwnProperty.call(obj, "a");
({}).hasOwnProperty.call(obj, "a");
const hasProperty = Object.prototype.hasOwnProperty.call(object, property);

Examples of correct code for this rule:

Object.hasOwn(obj, "a");
const hasProperty = Object.hasOwn(object, property);

How to use

To enable this rule using the config file or in the CLI, you can use:

Config (.oxlintrc.json)

{
  "rules": {
    "prefer-object-has-own": "error"
  }
}

CLI

oxlint --deny prefer-object-has-own

References

• Rule Source