@typescript-eslint/no-useless-constructor

A class without a constructor gets one for free. In a base class it's empty, and in a subclass it passes all arguments to super(). Writing that out by hand adds lines that do nothing.

Configure

Off by default. To turn it on:

[lint.rules]
"@typescript-eslint/no-useless-constructor" = "error" # or "warn"

Examples

Reported:

class Store {
  constructor() {}
}

class HttpError extends Error {
  constructor(message: string) {
    super(message);
  }
}

Not reported:

class Store {}

class HttpError extends Error {}

class NotFoundError extends Error {
  constructor(path: string) {
    super(`${path} was not found`);
  }
}

An empty constructor is allowed if TypeScript gives it a job. A private or protected constructor limits who can create the class, a parameter property declares a field, and a decorator on a parameter runs code:

class Config {
  private constructor() {}
}

class User {
  constructor(public name: string) {}
}

A public constructor in a subclass is allowed too, because it can open up a protected one:

class Shape {
  protected constructor() {}
}

class Circle extends Shape {
  public constructor() {
    super();
  }
}