Mocking SQL Server database layer in Unit tests with C# and Moq

In this post I will describe how to mock database layer in Unit Tests with C# and Moq.

Why it is needed? Well, good question.
Tests that verify that DB communications works are no longer just unit tests, they are integration tests. But quite often integration tests require more complex setup, they take longer time to execute, there should be some initialization & deployment process done to make them reliable.  Also it is hard to test all of the corner cases like connectivity issues, invalid schemas or backward compatibility.

Coding Interview question: Given binary tree, return lists for the nodes for each tree level, with solution in C#

Coding Interview question: Given binary tree, return lists for the nodes for each tree level, with solution in C#

Interview quesiton: "Create Binary search tree out of sorted array" with solution in C#

Interview quesiton: "Create Binary search tree out of sorted array" with solution in C#

Interview task: Check if two nodes connected on directed graph, implementation in C#

Interview task: Check if two nodes connected on directed graph, implementation in C#
With Unit test

Interview quesiton: "Sort stack using only additional stack without other data structures" with solution in C#

Interview quesiton: "Sort stack using only additional stack without other data structures" with solution in C#

Coding interview question: "Implement queue using two stacks" with solution in C#

Coding interview question: "Implement queue using two stacks" with solution in C# With Unit test.

How to subsribe for Unit test run events in extension for Visual Studio?

I've had an idea to write extension for Visual Studio to play sounds on certain events.
In the first iteration I needed next events: build complete, breakpoint hit, unit test run finished.

Why? Because when you work with big solutions and big number of tests sometimes it takes a lot of time to wait for end of compilation/tests or when breakpoint is hit, especially if it is conditional. Usually I switch to different activities and miss moment when those actions end.

While build and debug events are pretty trivial (with one small know-how: in order to listen to the DebuggerEvents events you need to maintain a reference to DebuggerEvents itself. ), with test events things are bit more complicated. The DTE object do not provide unit test events. But solution was found and here how it can be done:

 

protected override void Initialize()
        {
            base.Initialize();


            var applicationObject = (DTE2)GetService(typeof(DTE));

            var componentModel =
                Microsoft.VisualStudio.Shell.Package.GetGlobalService(typeof(SComponentModel)) as IComponentModel;


            var operationState = componentModel.GetService< IOperationState>();
            operationState.StateChanged += OperationStateOnStateChanged;
        }

        private void OperationStateOnStateChanged(object sender, OperationStateChangedEventArgs operationStateChangedEventArgs)
        {
            if (operationStateChangedEventArgs.State.HasFlag(TestOperationStates.TestExecutionFinished))
            {//Do stuff}
        }

Next assembly needs to be referenced:

   $(DevEnvDir)\CommonExtensions\Microsoft\TestWindow\Microsoft.VisualStudio.TestWindow.Interfaces.dll

If you want to use it in extension for Visual Studio 2012, one more reference is needed:

      $(DevEnvDir)\PublicAssemblies\Microsoft.VisualStudio.ComponentModelHost.dll

By the way, I published those extension, it can be found here: Visual Studio Ding extension