public static void ThrowIfFrozen(IFreezable freezable)
{
if (freezable.IsFrozen)
{
throw new InvalidOperationException("Cannot mutate frozen " + freezable.GetType().Name);
}
}
public static void TestFreeze(IFreezable sut)
{
foreach (var property in sut.GetType().GetRuntimeProperties().Where(x => x.Name != "IsFrozen"))
{
var value =
property.PropertyType.IsValueType ?
Activator.CreateInstance(property.PropertyType) :
null;
property.SetValue(sut, value);
var result = property.GetValue(sut);
Assert.Equal(value, result);
}
sut.Freeze();
foreach (var property in sut.GetType().GetRuntimeProperties().Where(x => x.Name != "IsFrozen"))
{
var value =
property.PropertyType.IsValueType ?
Activator.CreateInstance(property.PropertyType) :
null;
Assert.Throws <InvalidOperationException>(() =>
{
try
{
property.SetValue(sut, value);
}
catch (Exception ex)
{
throw ex.InnerException;
}
});
}
}
public static bool SetRefPropertyOnce <TProperty>(this IFreezable that, ref TProperty thisProperty, TProperty value, [CallerMemberName] string callerMemberName = null)
where TProperty : class
{
if (ReferenceEquals(thisProperty, value))
{
return(false);
}
if ((object)thisProperty != null)
{
throw new System.ArgumentException($"{that.GetType().Name}.{callerMemberName} is already set.");
}
thisProperty = value;
return(true);
}
public static void ThrowIfNotFrozen(this IFreezable that, string name = null)
{
if ((object)that != null)
{
if (!(that.IsFrozen()))
{
if (name is null)
{
throw new InvalidOperationException($"{that.GetType().FullName} is NOT frozen.");
}
else
{
throw new InvalidOperationException($"{name} is NOT frozen.");
}
}
}
}
public static void SetOrThrowIfFrozen <T>(this IFreezable that, ref T target, T value, string name = null)
{
if ((object)that != null)
{
if (that.IsFrozen())
{
if (name is null)
{
throw new InvalidOperationException($"{that.GetType().FullName} is frozen.");
}
else
{
throw new InvalidOperationException($"{name} is frozen.");
}
}
}
target = value;
}