1 files changed, 39 insertions, 0 deletions
diff --git a/src/DotNetOpenAuth.InfoCard/InfoCardErrorUtilities.cs b/src/DotNetOpenAuth.InfoCard/InfoCardErrorUtilities.cs
new file mode 100644
index 0000000..da1c7ff
--- /dev/null
+++ b/src/DotNetOpenAuth.InfoCard/InfoCardErrorUtilities.cs
@@ -0,0 +1,39 @@
+//-----------------------------------------------------------------------
+// <copyright file="InfoCardErrorUtilities.cs" company="Andrew Arnott">
+//     Copyright (c) Andrew Arnott. All rights reserved.
+// </copyright>
+//-----------------------------------------------------------------------
+
+namespace DotNetOpenAuth {
+	using System;
+	using System.Collections.Generic;
+	using System.Diagnostics.Contracts;
+	using System.Globalization;
+	using System.Linq;
+	using System.Text;
+
+	/// <summary>
+	/// Error reporting methods specific to InfoCard validation.
+	/// </summary>
+	internal static class InfoCardErrorUtilities {
+		/// <summary>
+		/// Checks a condition and throws an <see cref="InfoCard.InformationCardException"/> 
+		/// if it evaluates to false.
+		/// </summary>
+		/// <param name="condition">The condition to check.</param>
+		/// <param name="errorMessage">The message to include in the exception, if created.</param>
+		/// <param name="args">The formatting arguments.</param>
+		/// <exception cref="InfoCard.InformationCardException">Thrown if <paramref name="condition"/> evaluates to <c>false</c>.</exception>
+		[Pure]
+		internal static void VerifyInfoCard(bool condition, string errorMessage, params object[] args) {
+			Requires.NotNull(args, "args");
+			Contract.Ensures(condition);
+			Contract.EnsuresOnThrow<InfoCard.InformationCardException>(!condition);
+			Contract.Assume(errorMessage != null);
+			if (!condition) {
+				errorMessage = string.Format(CultureInfo.CurrentCulture, errorMessage, args);
+				throw new InfoCard.InformationCardException(errorMessage);
+			}
+		}
+	}
+}