VSTest -> Microsoft.Testing.Platform Migration

Migrate a .NET test solution from VSTest to Microsoft.Testing.Platform (MTP). The outcome is a solution where all test projects run on MTP, dotnet test works correctly, and CI/CD pipelines are updated.

First Action

Inspect the supplied project, Directory.Build.props, global.json, and CI files before searching the web or answering from memory. Resolve the framework and SDK mode first: .NET 9 and earlier use the compatibility property plus the -- separator; .NET 10 native MTP uses global.json, removes that property, and passes MTP arguments without the separator. For central properties, never condition on IsTestProject in Directory.Build.props; use a property already available there, such as MSBuildProjectName.

Important: Do not mix VSTest-based and MTP-based .NET test projects in the same solution or run configuration -- this is an unsupported scenario.

When to Use