1 files changed, 67 insertions, 0 deletions
diff --git a/Xamarin.Forms.Xaml.UnitTests/XamlParseExceptionConstraint.cs b/Xamarin.Forms.Xaml.UnitTests/XamlParseExceptionConstraint.cs
new file mode 100644
index 00000000..cdff5ca8
--- /dev/null
+++ b/Xamarin.Forms.Xaml.UnitTests/XamlParseExceptionConstraint.cs
@@ -0,0 +1,67 @@
+using System;
+using NUnit.Framework.Constraints;
+
+namespace Xamarin.Forms.Xaml.UnitTests
+{	
+	public class XamlParseExceptionConstraint : ExceptionTypeConstraint
+	{
+		bool haslineinfo;
+		int linenumber;
+		int lineposition;
+		Func<string, bool> messagePredicate;
+
+		XamlParseExceptionConstraint (bool haslineinfo) : base (typeof (XamlParseException))
+		{
+			this.haslineinfo = haslineinfo;
+			DisplayName = "xamlparse";
+		}
+
+		public XamlParseExceptionConstraint () : this (false)
+		{
+		}
+
+		public XamlParseExceptionConstraint (int linenumber, int lineposition, Func<string, bool> messagePredicate = null) : this (true)
+		{
+			this.linenumber = linenumber;
+			this.lineposition = lineposition;
+			this.messagePredicate = messagePredicate;
+		}
+
+		public override bool Matches (object actual)
+		{
+			this.actual = actual;
+			if (!base.Matches (actual))
+				return false;
+			var xmlInfo = ((XamlParseException)actual).XmlInfo;
+			if (!haslineinfo)
+				return true;
+			if (xmlInfo == null || !xmlInfo.HasLineInfo ())
+				return false;
+			if (messagePredicate != null)
+				if (!messagePredicate (((XamlParseException)actual).UnformattedMessage))
+					return false;
+			return xmlInfo.LineNumber == linenumber && xmlInfo.LinePosition == lineposition;
+		}
+
+		public override void WriteDescriptionTo (MessageWriter writer)
+		{
+			base.WriteDescriptionTo (writer);
+			if (haslineinfo)
+				writer.Write (string.Format (" line {0}, position {1}", linenumber, lineposition));
+		}
+
+		public override void WriteActualValueTo (MessageWriter writer)
+		{
+			var ex = actual as XamlParseException;
+			writer.WriteActualValue ((actual == null) ? null : actual.GetType ());
+			if (ex != null) {
+				if (ex.XmlInfo != null && ex.XmlInfo.HasLineInfo ())
+					writer.Write (" line {0}, position {1}", ex.XmlInfo.LineNumber, ex.XmlInfo.LinePosition);
+				else 
+					writer.Write (" no line info");
+				writer.WriteLine (" ({0})", ex.Message);
+				writer.Write (ex.StackTrace);
+			}
+		}
+	}
+}
+\ No newline at end of file