@typescript-eslint/no-misused-new

A class declares its constructor with constructor. An interface describes one with new (). Swap them and you get an ordinary method. new(): Client in a class is a method named new, and constructor(): void in an interface is a method named constructor.

An interface with a new () that returns the interface itself is reported too. It says that you call new on an instance to get another instance, which is rarely what you mean. The new () belongs in the type of the class.

A method named new that has a body, or that returns some other type, isn't reported.

This rule is on by default in TypeScript files.

Configure

On by default as an error. To turn it off:

[lint.rules]
"@typescript-eslint/no-misused-new" = "off" # or "warn"

Examples

Reported:

declare class Client {
  new(): Client;
}

interface Session {
  new (): Session;
  constructor(): void;
}

Not reported:

declare class Client {
  constructor();
}

interface Session {
  id: string;
}

interface SessionConstructor {
  new (): Session;
}

class Factory {
  new() {
    return new Client();
  }
}