Nunittest of auto refill if WaterContainer

Question

I want to test if the water container is refilled when empty, below is my method's code:

//Tests if the water is refilled if empty.
public void RefillWaterContainerTest()
{
    Console.Write("Test the water refill");
    int EContainer = new WaterContainer();
    FillUpContainer();
    Assert.AreEqual(0, EContainer); 
}

The rest of the code is as follows:

public class WaterContainer : Container {
    public WaterContainer(int level) { Level = level; }
    public override void GetContent() { 
    if (HasContent()) {
            Level -= 1;
        } else {
            if (FillUpWater() == false) {
                throw new EmptyContainerException("No water.");
            } else {
                Level -= 1;
            }
        }
    }

    protected bool FillUpWater() {
        WaterTap tap = new WaterTap();
        if (tap.FillUpContainer()) {
            Level = 5; return true;
        } else {
            return false;
        }
    }
} //And the water tap class: class WaterTap { public bool FillUpContainer() { return true; } }

Answer 1

If WaterTap.FillUpContainer always returns true, then FillUpWater will never return false, which means that you never throw the EmptyContainerException, making any Tests rather pointless. I suggest fixing that first.

After that you can check if the exception is thrown by using Assert.Throws.

Assert.Throws(EmptyContainerException,FillUpContainer);