Add notes un xUnit

.NET/C#/Unit Testing.md

@@ -39,3 +39,28 @@ namespace Project.Tests
 
 [UnitTest Overloaded Methods](https://stackoverflow.com/a/5666591/8319610)
 [Naming standards for unit tests](https://osherove.com/blog/2005/4/3/naming-standards-for-unit-tests.html)
+
+## xUnit
+
+```cs
+using System;
+using Xunit;
+
+namespace Project.Tests
+{
+    public class ClassTest
+    {
+        [Fact]
+        public void TestMethod()
+        {
+            Assert.Equal(expected, actual);  // works on collections
+            Assert.True(bool);
+            Assert.False(bool);
+            Assert.NotNull(nullable);
+
+            // Verifies that all items in the collection pass when executed against action
+            Assert.All<T>(IEnumerable<T> collection, Action<T> action);
+        }
+    }
+}
+```