eslint/constructor-super Correctness

✅ This rule is turned on by default.

What it does

Requires super() calls in constructors of derived classes and disallows super() calls in constructors of non-derived classes.

This rule can be disabled for TypeScript code, as the TypeScript compiler enforces this check.

Why is this bad?

In JavaScript, calling super() in the constructor of a derived class (a class that extends another class) is required. Failing to do so will result in a ReferenceError at runtime. Conversely, calling super() in a non-derived class is a syntax error.

Examples

Examples of incorrect code for this rule:

// Missing super() call
class A extends B {
    constructor() { }
}

// super() in non-derived class
class A {
    constructor() {
        super();
    }
}

// super() only in some code paths
class C extends D {
    constructor() {
        if (condition) {
            super();
        }
    }
}

Examples of correct code for this rule:

// Proper super() call in derived class
class A extends B {
    constructor() {
        super();
    }
}

// No super() in non-derived class
class A {
    constructor() { }
}

// super() in all code paths
class C extends D {
    constructor() {
        if (condition) {
            super();
        } else {
            super();
        }
    }
}

How to use

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

Config (.oxlintrc.json)

{
    "rules": {
        "constructor-super": "error"
    }
}

CLI

oxlint --deny constructor-super

References

• Rule Source