New rule: StringBuilder.AppendJoin

[meziantou]

sb.Append(string.Join(',', new [] { "a", "b" }));

Should be:

sb.AppendJoin(',', new [] { "a", "b" });

[AraHaan]

Wait stringbulder can do that?

[meziantou]

https://docs.microsoft.com/en-us/dotnet/api/system.text.stringbuilder.appendjoin?view=netcore-3.1

[0liver]

@AraHaan It's a new method since .NET Core 2.0.