‘SuppressMessage’ for a whole namespace

Suppression of a code analysis warning for a namespace and all its descendant symbols is possible since Visual Studio 2019:

[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage(
    "Microsoft.Naming", "CA1707:IdentifiersShouldNotContainUnderscores",
    Justification = "Test methods require underscores for readability."
    Scope = "namespaceanddescendants", Target = "Company.Product.Tests")]

Scope – The target on which the warning is being suppressed. If the target is not specified, it is set to the target of the attribute. Supported scopes include the following:

• …

• namespaceanddescendants – (New for Visual Studio 2019) This scope suppresses warnings in a namespace and all its descendant symbols. The namespaceanddescendants value is only valid for Roslyn analyzers, and is ignored by binary, FxCop-based static analysis.

^{Suppress code analysis warnings#SuppressMessage attribute @ MS Docs}