Why does StyleCopAnalyzers think that global usings should be declared within a namespace, when such syntax is not possible?

Question

I am creating a NUnit test project and in the creation of that, MS Visual Studio has created a file called Usings.cs with the line

global using NUnit.Framework;

which tells the project to include the NUnit framework in every file.

I have been running StyleCopAnalyzers over this test project, and it keeps reporting

SA1200: Using directive should appear within a namespace declaration.

However, when I put the global using within a namespace declaration

namespace TestProject
{
    global using NUnit.Framework;
}

I get the error

CS8914: A global using directive cannot be used in a namespace declaration.

What is the correct approach? Should I use the Usings.cs file with global usings?

Answer 1

In your .csproj add the following lines

 <ItemGroup>
    <Using Include="NUnit.Framework" />
  </ItemGroup>

Answer 2

Looks like the default may have changed. The fix involves updating your editor config file (.editorconfig) that should be in the same directory as your solution.

Look for the following

• csharp_using_directive_placement
• dotnet_diagnostic.SA1200.severity

You want them to look like

csharp_using_directive_placement = outside_namespace
dotnet_diagnostic.SA1200.severity = None

or just delete csharp_using_directive_placement to get the default behavior

dotnet_diagnostic.SA1200.severity = None

In my project, csharp_using_directive_placement was set to inside_namespace, and this is impossible in a global using file.