pkg/ipnet: Add DeepCopy(Into) support to IPNet

pkg/ipnet/ipnet.go

@@ -16,6 +16,35 @@ type IPNet struct {
 	net.IPNet
 }
 
+// String returns a CIDR serialization of the subnet, or an empty
+// string if the subnet is nil.
+func (ipnet *IPNet) String() string {
+	if ipnet == nil {
+		return ""
+	}
+	return ipnet.IPNet.String()
+}
+
+// DeepCopyInto copies the receiver into out.  out must be non-nil.
+func (ipnet *IPNet) DeepCopyInto(out *IPNet) {
+	if ipnet == nil {
+		*out = *new(IPNet)
+	} else {
+		*out = *ipnet
+	}
+	return
+}
+
+// DeepCopy copies the receiver, creating a new IPNet.
+func (ipnet *IPNet) DeepCopy() *IPNet {
+	if ipnet == nil {
+		return nil
+	}
+	out := new(IPNet)
+	ipnet.DeepCopyInto(out)
+	return out
+}
+
 // MarshalJSON interface for an IPNet
 func (ipnet IPNet) MarshalJSON() (data []byte, err error) {
 	if reflect.DeepEqual(ipnet.IPNet, emptyIPNet) {

pkg/ipnet/ipnet_test.go

@@ -38,25 +38,60 @@ func TestUnmarshal(t *testing.T) {
 			Mask: net.IPv4Mask(255, 255, 255, 0),
 		}},
 	} {
-		data, err := json.Marshal(ipNetIn)
-		if err != nil {
-			t.Fatal(err)
-		}
+		t.Run(ipNetIn.String(), func(t *testing.T) {
+			data, err := json.Marshal(ipNetIn)
+			if err != nil {
+				t.Fatal(err)
+			}
 
-		t.Run(string(data), func(t *testing.T) {
 			var ipNetOut *IPNet
-			err := json.Unmarshal(data, &ipNetOut)
+			err = json.Unmarshal(data, &ipNetOut)
 			if err != nil {
 				t.Fatal(err)
 			}
 
-			if ipNetIn == nil {
-				if ipNetOut != nil {
-					t.Fatalf("%v != %v", ipNetOut, ipNetIn)
-				}
-			} else if ipNetOut.String() != ipNetIn.String() {
+			if ipNetOut.String() != ipNetIn.String() {
 				t.Fatalf("%v != %v", ipNetOut, ipNetIn)
 			}
 		})
 	}
 }
+
+func TestDeepCopy(t *testing.T) {
+	for _, ipNetIn := range []*IPNet{
+		{},
+		{IPNet: net.IPNet{
+			IP:   net.IP{192, 168, 0, 10},
+			Mask: net.IPv4Mask(255, 255, 255, 0),
+		}},
+	} {
+		t.Run(ipNetIn.String(), func(t *testing.T) {
+			t.Run("DeepCopyInto", func(t *testing.T) {
+				ipNetOut := &IPNet{IPNet: net.IPNet{
+					IP:   net.IP{10, 0, 0, 0},
+					Mask: net.IPv4Mask(255, 0, 0, 0),
+				}}
+
+				ipNetIn.DeepCopyInto(ipNetOut)
+				if ipNetOut.String() != ipNetIn.String() {
+					t.Fatalf("%v != %v", ipNetOut, ipNetIn)
+				}
+			})
+
+			t.Run("DeepCopy", func(t *testing.T) {
+				ipNetOut := ipNetIn.DeepCopy()
+				if ipNetOut.String() != ipNetIn.String() {
+					t.Fatalf("%v != %v", ipNetOut, ipNetIn)
+				}
+
+				ipNetIn.IPNet = net.IPNet{
+					IP:   net.IP{192, 168, 10, 10},
+					Mask: net.IPv4Mask(255, 255, 255, 255),
+				}
+				if ipNetOut.String() == ipNetIn.String() {
+					t.Fatalf("%v (%q) == %v (%q)", ipNetOut, ipNetOut.String(), ipNetIn, ipNetIn.String())
+				}
+			})
+		})
+	}
+}