thisBeforeSuper

Reports using this or super before calling super() in derived class constructors.

✅ This rule is included in the ts untyped presets.

In JavaScript, when a class extends another class, the constructor must call super() before accessing this or super.property. Attempting to access this or super properties before calling super() throws a ReferenceError.

Examples

❌ Incorrect

class Child extends Parent {
  constructor() {
    this.value = 0;
    super();
  }
}

class Child extends Parent {
  constructor() {
    super.initialize();
    super();
  }
}

✅ Correct

class Child extends Parent {
  constructor() {
    super();
    this.value = 0;
  }
}

class Child extends Parent {
  constructor() {
    super();
    super.initialize();
  }
}

Options

This rule is not configurable.

When Not To Use It

If your code is transpiled in a way that does not match modern ECMAScript semantics, this rule may not be for you.

Further Reading

• MDN: super
• MDN: Classes

Equivalents in Other Linters

• Biome: noUnreachableSuper
• Deno: no-this-before-super
• ESLint: no-this-before-super
• Oxlint: eslint/no-this-before-super