Unit testing your MAUI project

Note: I found this didn’t work correctly on Visual Studio for Mac, I’ll update the post further if I do get it working.

This post is pretty much a duplicate of Adding xUnit Test to your .NET MAUI Project but just simplified for me to quickly repeat the steps which allow me to write unit tests against my MAUI project code.

So, you want to unit test some code in your MAUI project. It’s not quite as simple as just creating a test project then referencing the MAUI project. Here are the steps to create an NUnit test project with .NET 7 (as my MAUI project has been updated to .NET 7).

  • Add a new NUnit Test Project to the solution via right mouse click on the solution, Add | Project and select NUnit Test Project
  • Open the MAUI project (csproj) file and prepend the net7.0 to the TargetFrameworks so it looks like this 
    <TargetFrameworks>net7.0;net7.0-android;net7.0-ios;net7.0-maccatalyst</TargetFrameworks>
  • Replace <OutputType>Exe</OutputType> with the following 
    <OutputType Condition="'$(TargetFramework)' != 'net7.0'">Exe</OutputType>

    Yes, this is TargetFramework singular. You may need to reload the project.

  • Now in your unit test project you can reference this MAUI project and write your tests

So, why did we carry out these steps?

Our test project was targeting .NET 7.0 but our MAUI project was targeting different platform implementations of the .NET 7 frameworks, i.e those for Android etc. We need the MAUI project to build a .NET 7.0 compatible version hence added the net7.0 to the TargetFrameworks.

The change to add the OutputType ensures that we only build an EXE output for those other frameworks, and therefore for .NET 7.0 we’ll have a DLL to reference instead in our tests.

Now we can build and run our unit tests.