This is a good source. https://docs.microsoft.com/en-us/dotnet/core/testing/unit-testing-with-mstest
mkidr MyConsoleProjectWithUnitTest
cd MyConsoleProjectWithUnitTest/
dotnet new sln
mkdir HelloWorldConsole
cd HelloWorldConsole/
dotnet new console
(or dotnet new classlib for creating Library instead of console project)
dotnet run
cd ..
mkdir HelloWorldConsole.Tests
cd HelloWorldConsole.Tests/
dotnet new mstest
dotnet add reference ../HelloWorldConsole/HelloWorldConsole.csproj
cd ..
dotnet sln add HelloWorldConsole/HelloWorldConsole.csproj
dotnet sln add HelloWorldConsole.Tests/HelloWorldConsole.Tests.csproj
code .
# Make modifications to your tests, program.
Cd HelloWorldConsole.Tests
dotnet test