namespace NUnit.Framework.Constraints { public class SubstringConstraint : StringConstraint { public SubstringConstraint(string expected) : base(expected) { descriptionText = "String containing"; } protected override bool Matches(string actual) { if (caseInsensitive) { if (actual != null) return actual.ToLower().IndexOf(expected.ToLower()) >= 0; return false; } if (actual != null) return actual.IndexOf(expected) >= 0; return false; } } }