eslint/no-extend-native Suspicious
What it does
Prevents extending native global objects such as Object, String, or Array with new properties.
Why is this bad?
Extending native objects can cause unexpected behavior and conflicts with other code.
For example:
js
// Adding a new property, which might seem okay
Object.prototype.extra = 55;
// Defining a user object
const users = {
1: "user1",
2: "user2",
};
for (const id in users) {
// This will print "extra" as well as "1" and "2":
console.log(id);
}Examples
Examples of incorrect code for this rule:
js
Object.prototype.p = 0;
Object.defineProperty(Array.prototype, "p", { value: 0 });Examples of correct code for this rule:
js
x.prototype.p = 0;
Object.defineProperty(x.prototype, "p", { value: 0 });Configuration
This rule accepts a configuration object with the following properties:
exceptions
type: string[]
default: []
A list of objects which are allowed to be exceptions to the rule.
How to use
To enable this rule using the config file or in the CLI, you can use:
json
{
"rules": {
"no-extend-native": "error"
}
}ts
import { defineConfig } from "oxlint";
export default defineConfig({
rules: {
"no-extend-native": "error",
},
});bash
oxlint --deny no-extend-nativeVersion
This rule was added in v0.9.7.