4. Project Types - tom-englert/ProjectConfigurationManager GitHub Wiki

In the Project Types tab you can see and change the project type of all your projects

You can e.g. mark projects as test project to show a proper icon in the solution explorer.

Be aware that sometimes the order of selection is important, e.g. you can't mark a project as WPF project if it does not already have the C# or VB project type selected.