Fix S3459 FP: Backing field with `ref` property

[dotjpg3141]

Description

False Positive of S3459 for backing field with ref property.

Repro steps

public class MyClass
{
    private int _foo;

    public ref int Foo => ref _foo;
}

Expected behavior

No warning

Actual behavior

warning S3459: Remove unassigned field '_foo', or set its value. (https://rules.sonarsource.com/csharp/RSPEC-3459)

Known workarounds

Supress this warning manually

Related information

• C#/VB.NET Plugins version: SonarAnalyzer.CSharp 9.23.2.88755
• Visual Studio version 17.9.2
• MSBuild / dotnet version: dotnet 8.0.200
• SonarScanner for .NET version (if used)
• Operating System: Windows 10

[CristianAmbrosini]

Hi @dotjpg3141! I confirm this as a FP, I'll add a reproducer in our codebase shortly.
Thanks!