Creating the ValidationError interface

Create a new file at src/validators/errors/validation-error.js and add a class definition for ValidationError:

class ValidationError extends Error {
  constructor(...params) {
    super(...params);

    if (Error.captureStackTrace) {
      Error.captureStackTrace(this, ValidationError);
    }
  }
}

export default ValidationError;

The preceding code extends the Error class to create its own class. We need to do this in order to distinguish between validation errors (which should return a 400 response) and errors in our code (which should return a 500 response).