S3900 does not consider `string.IsNullOrWhitespace()` as a parameter check

The last three statements all report S3900 despite the values being inspected for null prior to being used.

public static string MyFunc(string arg1, string arg2, string arg3)
{

	if (string.IsNullOrWhiteSpace(arg1) == true)
	{
		throw new ArgumentNullException(nameof(arg1));
	}

	if (string.IsNullOrWhiteSpace(arg2) == true)
	{
		 throw new ArgumentNullException(nameof(arg2));
	}

	if (string.IsNullOrWhiteSpace(arg3) == true)
	{
		 throw new ArgumentNullException(nameof(arg3));
	}

	var val1  = Encoding.UTF8.GetBytes(arg2.Substring(0, 32));
	var val2 = Encoding.UTF8.GetBytes(arg3.Substring(0, 16));
	var val3 = arg1.Replace('*', '/').Replace(' ', '+');
	
1 Like

Hi @StingyJack

Thank you for your feedback!
There is an existing issue for False Positives for string.IsNullOrEmpty for rule S3900.
I added the string.IsNullOrWhiteSpace() case to that issue. You can track the progress there.