constructor-super.md

title	layout	edit_link	rule_type
constructor-super	doc	https://github.com/eslint/eslint/edit/main/docs/src/rules/constructor-super.md	problem

Constructors of derived classes must call super(). Constructors of non derived classes must not call super(). If this is not observed, the JavaScript engine will raise a runtime error.

This rule checks whether or not there is a valid super() call.

Rule Details

This rule is aimed to flag invalid/missing super() calls.

Examples of incorrect code for this rule:

:::incorrect

/*eslint constructor-super: "error"*/
/*eslint-env es6*/

class A {
    constructor() {
        super();  // This is a SyntaxError.
    }
}

class A extends B {
    constructor() { }  // Would throw a ReferenceError.
}

// Classes which inherits from a non constructor are always problems.
class A extends null {
    constructor() {
        super();  // Would throw a TypeError.
    }
}

class A extends null {
    constructor() { }  // Would throw a ReferenceError.
}

:::

Examples of correct code for this rule:

:::correct

/*eslint constructor-super: "error"*/
/*eslint-env es6*/

class A {
    constructor() { }
}

class A extends B {
    constructor() {
        super();
    }
}

:::

When Not To Use It

If you don't want to be notified about invalid/missing super() callings in constructors, you can safely disable this rule.