alternativeClasses.js

// From Fixing Object oriented abusers, Manh Phan https://ducmanhphan.github.io/2020-01-24-Fixing-object-oriented-abusers/

class CheckoutHandlder {
  // ...
  convertToCurrency(price, currencyTo) {
    if (currencyTo === "EUR") {
      return price * 0.9;
    } else if (currencyTo === "CAD") {
      return price * 1.35;
    } else {
      throw new Error("Unrecognized currency: " + currencyTo);
    }
  }
}


class SimpleCurrencyConverter {
 
  public construct(currencyTo) {
    this.currencyTo = currencyTo;
  }

  convert(price) {
    if (this.currencyTo === "EUR") {
      return price * 0.9;
    } else if (this.currencyTo === "CAD") {
      return price * 1.35;
    } else {
      throw new Error("Unrecognized currency: " + this.currencyTo);
    }
  }
}