vehicle-purchase.spec.js

import {
  needsLicense,
  chooseVehicle,
  calculateResellPrice,
} from './vehicle-purchase';

describe('vehicle purchase', () => {
  describe('needsLicense', () => {
    test('requires a license for a car', () => {
      expect(needsLicense('car')).toBe(true);
    });

    test('requires a license for a truck', () => {
      expect(needsLicense('truck')).toBe(true);
    });

    test('does not require a license for a bike', () => {
      expect(needsLicense('bike')).toBe(false);
    });

    test('does not require a license for a stroller', () => {
      expect(needsLicense('stroller')).toBe(false);
    });

    test('does not require a license for an e-scooter', () => {
      expect(needsLicense('e-scooter')).toBe(false);
    });
  });

  describe('chooseVehicle', () => {
    const rest = ' is clearly the better choice.';

    test('correctly recommends the first option', () => {
      expect(chooseVehicle('Bugatti Veyron', 'Ford Pinto')).toBe(
        'Bugatti Veyron' + rest
      );
      expect(chooseVehicle('Chery EQ', 'Kia Niro Elektro')).toBe(
        'Chery EQ' + rest
      );
    });

    test('correctly recommends the second option', () => {
      expect(chooseVehicle('Ford Pinto', 'Bugatti Veyron')).toBe(
        'Bugatti Veyron' + rest
      );
      expect(chooseVehicle('2020 Gazelle Medeo', '2018 Bergamont City')).toBe(
        '2018 Bergamont City' + rest
      );
    });
  });

  describe('calculateResellPrice', () => {
    test('price is reduced to 80% for age below 3', () => {
      expect(calculateResellPrice(40000, 2)).toBe(32000);
      expect(calculateResellPrice(40000, 2.5)).toBe(32000);
    });

    test('price is reduced to 50% for age above 10', () => {
      expect(calculateResellPrice(40000, 12)).toBe(20000);
    });

    test('price is reduced to 70% for between 3 and 10', () => {
      expect(calculateResellPrice(25000, 7)).toBe(17500);
    });

    test('works correctly for threshold age 3', () => {
      expect(calculateResellPrice(40000, 3)).toBe(28000);
    });

    test('works correctly for threshold age 10', () => {
      expect(calculateResellPrice(25000, 10)).toBe(17500);
    });
  });
});