support rangepoints in self-test

Summary:
We have a self-test that makes sure we get responses from all subnets as defined by ipmaps.
It was a follow-up to the incident we had, and I wanna keep it working.
As we use rangepoints more now, I'm updating the selftest to support doing the same check with them.

Reviewed By: t3lurid3

Differential Revision: D57490993

fbshipit-source-id: 52d53ef9f5b7dc8fa787e9bfa3fa0b992ad780c8

dnsrocks/dnsdata/selftest_helpers.go

@@ -38,15 +38,20 @@ func GetSubnets(dataPath string) ([]*net.IPNet, error) {
 			continue
 		}
 		rtype := decodeRtype(line)
-		if rtype != prefixNet {
+		if rtype != prefixNet && rtype != prefixRangePoint {
 			continue
 		}
 		r, err := codec.DecodeLn(line)
 		if err != nil {
 			return nets, fmt.Errorf("error decoding %s: %w", string(line), err)
 		}
-		rr := r.(*Rnet)
-		nets = append(nets, rr.ipnet)
+		switch rr := r.(type) {
+		case *Rnet:
+			nets = append(nets, rr.ipnet)
+		case *Rrangepoint:
+			n := &net.IPNet{IP: net.IP(rr.pt.rangeStart[:]), Mask: net.CIDRMask(int(rr.pt.location.maskLen), 128)}
+			nets = append(nets, n)
+		}
 	}
 	if err := scanner.Err(); err != nil {
 		return nets, err