Less than in Groovy case/switch statement

I have the following switch statement

    switch (points) {
       case 0: name = "new"; break;
       case 1..14: badgeName = "bronze-coin"; break;
       case 15..29: badgeName = "silver-coin"; 开发者_运维知识库break;
       default: badgeName = "ruby";
    }

I'd like the first case (case 0) to include points less than or equal to 0. How can I do this in Groovy?

switch(points)
{
    case Integer.MIN_VALUE..0: badgeName = "new"; break;
    case 1..14: badgeName = "bronze-coin"; break;
    case 15..29: badgeName = "silver-coin"; break;
    default: badgeName = "ruby";
}

case { it instanceof Integer && it < 0 }: