namespace NUnit.Framework.Constraints { public abstract class PrefixConstraint : Constraint { protected IConstraint BaseConstraint { get; set; } protected string DescriptionPrefix { get; set; } public override string Description => FormatDescription(DescriptionPrefix, BaseConstraint); protected PrefixConstraint(IResolveConstraint baseConstraint) : base(baseConstraint) { Guard.ArgumentNotNull(baseConstraint, "baseConstraint"); BaseConstraint = baseConstraint.Resolve(); } internal static string FormatDescription(string descriptionPrefix, IConstraint baseConstraint) { return string.Format((baseConstraint is EqualConstraint) ? "{0} equal to {1}" : "{0} {1}", descriptionPrefix, baseConstraint.Description); } } }