no-class-assign.md

title	layout	edit_link	rule_type
no-class-assign	doc	https://github.com/eslint/eslint/edit/main/docs/src/rules/no-class-assign.md	problem

ClassDeclaration creates a variable, and we can modify the variable.

/*eslint-env es6*/

class A { }
A = 0;

But the modification is a mistake in most cases.

Rule Details

This rule is aimed to flag modifying variables of class declarations.

Examples of incorrect code for this rule:

::: incorrect

/*eslint no-class-assign: "error"*/
/*eslint-env es6*/

class A { }
A = 0;

:::

::: incorrect

/*eslint no-class-assign: "error"*/
/*eslint-env es6*/

A = 0;
class A { }

:::

::: incorrect

/*eslint no-class-assign: "error"*/
/*eslint-env es6*/

class A {
    b() {
        A = 0;
    }
}

:::

::: incorrect

/*eslint no-class-assign: "error"*/
/*eslint-env es6*/

let A = class A {
    b() {
        A = 0;
        // `let A` is shadowed by the class name.
    }
}

:::

Examples of correct code for this rule:

::: correct

/*eslint no-class-assign: "error"*/
/*eslint-env es6*/

let A = class A { }
A = 0; // A is a variable.

:::

::: correct

/*eslint no-class-assign: "error"*/
/*eslint-env es6*/

let A = class {
    b() {
        A = 0; // A is a variable.
    }
}

:::

::: correct

/*eslint no-class-assign: 2*/
/*eslint-env es6*/

class A {
    b(A) {
        A = 0; // A is a parameter.
    }
}

:::

When Not To Use It

If you don't want to be notified about modifying variables of class declarations, you can safely disable this rule.