Fix S3900 FP: Recognize ArgumentNullException.ThrowIfNull()

[bart-vmware]

Description

S3900 (Arguments of public methods should be validated against null) does not recognize the usage of ArgumentNullException.ThrowIfNull(), which was added in .NET 6.

Repro steps

public class Example
{
    public void Run(string name)
    {
        ArgumentNullException.ThrowIfNull(name);

        int len = name.Length; // FP S3900
    }
}

Expected behavior

No warning reported.

Actual behavior

Warning reported.

Known workarounds

Suppress S3900.

Related information

• C#/VB.NET Plugins version: SonarAnalyzer.CSharp (NuGet package) v8.40.0.48530
• Visual Studio version: Microsoft Visual Studio Community 2022 (64-bit) v17.2.3
• MSBuild version: Microsoft (R) Build Engine version 17.2.1+52cd2da31 for .NET Framework, v17.2.1.25201
• dotnet version: v6.0.300
• SonarScanner for .NET version (if used): ?
• Operating System: Windows 10 Enterprise 21H2 x64 ENU, v19044.1706

[pavel-mikula-sonarsource]

Hi @bart-vmware,

Thank you for reporting this, I confirm it as FP. We plan to fix it as part of MMF-2401 (not a public link, unfortunately)

[bart-vmware]

The same issue applies to:

• S4456: Parameter validation in yielding methods should be wrapped
• S4457: Parameter validation in "async"/"await" methods should be wrapped

I couldn't find a product roadmap. Do you have any idea or rough estimation when this will be released?

Edit: mentioned S4456 twice, instead of S4456 and S4457.

[pavel-mikula-sonarsource]

Please create a new issue with reproducers for the S4456. That has a different root cause (and might be way easier to fix).

There's no official ETA for the MMFs. My guess is that MMF-2401 will be available in 3rd analyzer release from now. We release roughly every 3-4 weeks.

[bart-vmware]

Thanks, that estimation is helpful. I've created #5744 for S4456/S4457.

[martin-strecker-sonarsource]

see also #6083

[pavel-mikula-sonarsource]

The implementation should also cover ArgumentException.ThrowIfNullOrEmpty

[milbrandt]

It's hard to accept, that this is not fixed in the current 9.9 LTS. As the next LTS will be in around 18 month, i.e. autumn 2024, then the next .NET 8 LTS with C# 12 will be deliverd for several months. And SonarQube we can no longer update the scanners of an installed SonarQube server.

[martin-strecker-sonarsource]

ArgumentNullException.ThrowIfNull() is supported by S3900 in version 8.56 of the analyzer. The issue stays open until https://github.com/SonarSource/sonar-dotnet/pull/7039 is merged which contains test coverage for the feature.

[Mrxx99]

I am on Version 9.9.3 (build 79811) (selfhosted) and ArgumentNullException.ThrowIfNull is not recognized. e.g. code like this:

string Method(string parameter)
{
  ArgumentNullException.ThrowIfNull(parameter);
  return paramter.ToUpper();
}
Still produces S3900.