Fix S3220 FP: Rule does not take into account generics

[RenderMichael]

Description

The following code produces a S3220 warning at the Caller.Test<T>(string key) method, even though the generic parameter is crucial to the method's execution.

Repro steps

internal static class Called
{
    public static T? Get<T>(params string[] key)
    {
        ArgumentNullException.ThrowIfNull(key);
        return default;
    }

    public static string? Get(string key)
    {
        ArgumentNullException.ThrowIfNull(key);
        return default;
    }
}

internal static class Caller
{
    public static T? Test<T>(string key)
    {
        return Called.Get<T>(key);
    }
}

Expected behavior

No warning.

Actual behavior

Warning.

Known workarounds

Not without violating S3878.

Related information

I'm using the Visual Studio extension, version 7.5.0.82292

[Tim-Pohlmann]

Hi @RenderMichael, very good catch! We will address this in a future hardening sprint. Thanks for the report!