public void InsertCoinUpdatesCoinListAndValueAndDisplay(decimal coinWeight, decimal coinSize, CoinType expectedCoinType, decimal expectedValue)
{
var coin = new Coin(coinWeight, coinSize);
var system = new VendingSystem(products, bankedCoins);
system.InsertCoin(coin);
Assert.True(system.InsertedCoins.Select(coin => coin.CoinType).First() == expectedCoinType);
Assert.True(system.InsertedCoins.Select(coin => coin.Value).First() == expectedValue);
Assert.Equal("$" + expectedValue.ToString("0.00"), system.Display);
}
