using System; namespace NUnit.Framework.Constraints { public abstract class StringConstraint : Constraint { protected string expected; protected bool caseInsensitive; protected string descriptionText; public override string Description { get { string text = $"{descriptionText}""{MsgUtils.FormatValue(expected)}"; if (caseInsensitive) text += ", ignoring case"; return text; } } public StringConstraint IgnoreCase { get { caseInsensitive = true; return this; } } protected StringConstraint() { } protected StringConstraint(string expected) : base(expected) { this.expected = expected; } public override ConstraintResult ApplyTo<TActual>(TActual actual) { string text = actual as string; if (actual != null && text == null) throw new ArgumentException("Actual value must be a string", "actual"); return new ConstraintResult(this, actual, Matches(text)); } protected abstract bool Matches(string actual); } }