public void HasValue_ReturnsFalse_WhenProvidedWithNullValue()
{
var c = ClosedMonadType.GetConstructorsWithParameters()
.Single(x => x.Parameters.Count == 1 &&
x.Parameters[0].ParameterType == ValueType)
.Method;
IMaybe maybe = c.Invoke(new object[] { null }) as IMaybe;
Assert.IsNotNull(maybe);
Assert.IsFalse(maybe.HasValue);
}
public void Value_ThrowsInvalidOperationException_WhenConstructedWithNullValue()
{
var c = ClosedMonadType.GetConstructorsWithParameters()
.Single(x => x.Parameters.Count == 1 &&
x.Parameters[0].ParameterType == ValueType)
.Method;
IMaybe maybe = c.Invoke(new object[] { null }) as IMaybe;
Assert.IsNotNull(maybe);
Assert.Throws <InvalidOperationException>(() => { object value = maybe.Value; });
}
public void Constructor_ThrowsArgumentNullException_WhenConstructedWithNullComputationFunction()
{
var c = ClosedMonadType.GetConstructorsWithParameters()
.Single(x => x.Parameters.Count == 1 &&
x.Parameters[0].ParameterType == typeof(Func <>).MakeGenericType(ClosedMonadType))
.Method;
var ex = Assert.Throws <TargetInvocationException>(() => c.Invoke(new object[] { null }));
var anex = ex.InnerException as ArgumentNullException;
Assert.IsNotNull(anex);
Assert.AreEqual("computation", anex.ParamName);
}