Add notes about Mocking

DotNet/C#/Unit Testing.md

@@ -1,42 +1,5 @@
 # Unit Testing
 
-## MSTest
-
-[Microsoft Unit Testing Tutorial](https://docs.microsoft.com/en-us/visualstudio/test/walkthrough-creating-and-running-unit-tests-for-managed-code?view=vs-2019)
-
-To test a project add a **MSTest Test Projet** to the solution.
-
-The test runner will execute any methods marked with `[TestInitialize]` once for every test the class contains, and will do so before running the actual test method itself.  
-The `[TestMethod]` attribute tells the test runner which methods represent tests.
-
-In `TestClass.cs`:
-
-```cs
-using System;
-using Microsoft.VisualStudio.TestTools.UnitTesting;
-
-namespace Project.Tests
-{
-    [TestClass]
-    public class TestClass
-    {
-        [TestMethod]
-        public void TestMethod()
-        {
-            Assert.AreEqual(expected, actual);
-            Assert.IsTrue(bool);
-            Assert.IsFalse(bool);
-            Assert.IsNotNull(nullable);
-
-            // assertions on collections
-            CollectionAssert.AreEqual(expexcted, actual),
-        }
-    }
-}
-```
-
----
-
 [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)
 
@@ -64,3 +27,18 @@ namespace Project.Tests
     }
 }
 ```
+
+## Mocking with Moq
+
+```cs
+var mockObj = new Mock<MockedType>();
+
+mockObj.Setup(m => m.Method(It.IsAny<InputType>())).Returns(value);
+mockObj.Object;  // get mock
+
+// check that the invocation is forwarded to the mock, n times
+mockObj.Verify(m => m.Method(It.IsAny<InputType>()), Times.Once());
+
+// check that the invocation is forwarded to the mock with a specific input
+mockObj.Verify(m => m.Method(input), Times.Once());
+```