Car Composition Tests

Car.js

const { movement } = require('./props');

const { park, drive } = movement;

module.exports = {
  movement: {
    park,
    drive
  }
};

package.json

{
  "scripts": {
    "test": "mocha"
  },
  "dependencies": {
    "mocha": "^5.2.0"
  }
}

props.js

const movement = {
  park: 'stopped',
  drive: 'vroom',
  fly: 'phewww'
};

const projectile = {
  fire: 'burn',
  laser: 'beam',
  antimatter: 'begone'
};

module.exports = { movement, projectile };

test.js

const assert = require('assert');

const Car = require('./Car');
const { movement, projectile } = require('./props');

const { park, drive, fly } = movement;
const { fire, laser, antimatter } = projectile;

////////////////////////////////////////////////////////////////

beforeEach(() => {
  car = Object.assign({}, Car);
});

describe('Car', () => {
  it('can move', () => {
    assert.equal(Object.getOwnPropertyNames(car).includes('movement'), true);
  });

  it('can park by default', () => {
    assert.equal(car.movement.park, 'stopped');
  });

  it('can drive by default', () => {
    assert.equal(car.movement.drive, 'vroom');
  });

  it('cannot fly by default', () => {
    assert.notEqual(car.movement.fly, 'phewww');
  });

  it('can fly', () => {
    car.movement.fly = fly;
    assert.equal(car.movement.fly, 'phewww');
  });

  it('cannot shoot by default', () => {
    assert.equal(Object.getOwnPropertyNames(car).includes('projectile'), false);
  });

  it('can shoot', () => {
    car.projectile = projectile;
    assert.equal(Object.getOwnPropertyNames(car).includes('projectile'), true);
  });

  it('can shoot lasers only', () => {
    car = { ...Car, projectile: { laser } };
    assert.equal(Object.values(car.projectile).join(' '), 'beam');
  });

  it('can shoot fire, lasers, and anti-matter', () => {
    car.projectile = projectile;
    assert.equal(Object.values(car.projectile).join(' '), 'burn beam begone');
  });
});