[](https://circleci.com/gh/YasushiKobayashi/js-modules)
npm install extend-err
extend-err> TODO: description
$ yarn add extend-err
$ npm i -S extend-err
$3
typescript
class CustomError extends ExtendErr implements CustomErrorInterface {
constructor(message?: string | Error, error?: Error) {
super(message, error); this.name = new.target.name;
Object.setPrototypeOf(this, new.target.prototype);
}
}
``https://github.com/YasushiKobayashi/js-modules/blob/master/src/extend-err/src/extend-err.spec.ts