namespace Mr.BrickAdventures.Progression.Tests;

public class CoinsTests
{
    [Fact]
    public void Subtracting_more_than_held_fails_and_leaves_the_amount_untouched()
    {
        var held = Coins.Of(10);

        var succeeded = held.TrySubtract(Coins.Of(30), out var remaining);

        Assert.False(succeeded);
        // Not clamped to zero. A caller that ignores the bool sees coins un-spent,
        // which is the safe outcome; clamping would silently consume what wasn't there.
        Assert.Equal(Coins.Of(10), remaining);
    }

    [Fact]
    public void A_negative_quantity_of_coins_cannot_exist()
    {
        Assert.Throws<ArgumentOutOfRangeException>(() => Coins.Of(-1));
    }
}