diff --git a/CSUtilities.Tests/Extensions/StringExtensionsTests.cs b/CSUtilities.Tests/Extensions/StringExtensionsTests.cs
new file mode 100644
index 0000000..70f7068
--- /dev/null
+++ b/CSUtilities.Tests/Extensions/StringExtensionsTests.cs
@@ -0,0 +1,15 @@
+using CSUtilities.Extensions;
+using Xunit;
+
+namespace CSUtilities.Tests.Extensions
+{
+	public class StringExtensionsTests
+	{
+		[Fact]
+		public void IsNullOrEmptyTest()
+		{
+			string n = null;
+			Assert.True(n.IsNullOrEmpty());
+		}
+	}
+}
diff --git a/CSUtilities/Extensions/StringExtensions.cs b/CSUtilities/Extensions/StringExtensions.cs
index a887c4c..425a1b3 100644
--- a/CSUtilities/Extensions/StringExtensions.cs
+++ b/CSUtilities/Extensions/StringExtensions.cs
@@ -1,10 +1,10 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Runtime.CompilerServices;
 
 namespace CSUtilities.Extensions
 {
-	//TODO: refactor extensions
 	/// <summary>
 	/// String utility extensions.
 	/// </summary>
@@ -25,6 +25,14 @@ public static bool IsNullOrWhiteSpace(this string str)
 			return string.IsNullOrWhiteSpace(str);
 		}
 
+		public static void TrowIfNullOrEmpty(this string str, [CallerMemberName] string name = null)
+		{
+			if (string.IsNullOrEmpty(str))
+			{
+				throw new ArgumentException("", name);
+			}
+		}
+
 		/// <summary>
 		/// Return an array with all the lines.
 		/// </summary>