generalize cidr parsing and improve lua tests

internal/net/ipnet.go

@@ -18,6 +18,7 @@ package net
 
 import (
 	"net"
+	"sort"
 	"strings"
 )
 
@@ -51,3 +52,30 @@ func ParseIPNets(specs ...string) (IPNet, IP, error) {
 
 	return ipnetset, ipset, nil
 }
+
+// ParseCIDRs parses comma separated CIDRs into a sorted string array
+func ParseCIDRs(s string) ([]string, error) {
+	if s == "" {
+		return []string{}, nil
+	}
+
+	values := strings.Split(s, ",")
+
+	ipnets, ips, err := ParseIPNets(values...)
+	if err != nil {
+		return nil, err
+	}
+
+	cidrs := []string{}
+	for k := range ipnets {
+		cidrs = append(cidrs, k)
+	}
+
+	for k := range ips {
+		cidrs = append(cidrs, k)
+	}
+
+	sort.Strings(cidrs)
+
+	return cidrs, nil
+}

internal/net/ipnet_test.go

@@ -17,6 +17,8 @@ limitations under the License.
 package net
 
 import (
+	"reflect"
+	"sort"
 	"testing"
 )
 
@@ -32,3 +34,20 @@ func TestNewIPSet(t *testing.T) {
 		t.Errorf("Expected len=1: %d", len(ips))
 	}
 }
+
+func TestParseCIDRs(t *testing.T) {
+	cidr, _ := ParseCIDRs("invalid.com")
+	if cidr != nil {
+		t.Errorf("expected %v but got %v", nil, cidr)
+	}
+
+	expected := []string{"192.0.0.1", "192.0.1.0/24"}
+	cidr, err := ParseCIDRs("192.0.0.1, 192.0.1.0/24")
+	if err != nil {
+		t.Errorf("unexpected error %v", err)
+	}
+	sort.Strings(cidr)
+	if !reflect.DeepEqual(expected, cidr) {
+		t.Errorf("expected %v but got %v", expected, cidr)
+	}
+}