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 });