feat: replace copier with shallow copy (#154)

Co-authored-by: Matt Dainty <matt@bodgit-n-scarper.com>

Author: ldez

go.mod

@@ -9,7 +9,6 @@ require (
 	github.com/go-logr/logr v1.4.3
 	github.com/hashicorp/go-multierror v1.1.1
 	github.com/jcmturner/gokrb5/v8 v8.4.4
-	github.com/jinzhu/copier v0.4.0
 	github.com/miekg/dns v1.1.72
 	github.com/openshift/gssapi v0.0.0-20161010215902-5fb4217df13b
 	github.com/stretchr/testify v1.11.1

go.sum

@@ -149,8 +149,6 @@ github.com/jcmturner/gokrb5/v8 v8.4.4 h1:x1Sv4HaTpepFkXbt2IkL29DXRf8sOfZXo8eRKh6
 github.com/jcmturner/gokrb5/v8 v8.4.4/go.mod h1:1btQEpgT6k+unzCwX1KdWMEwPPkkgBtP+F6aCACiMrs=
 github.com/jcmturner/rpc/v2 v2.0.3 h1:7FXXj8Ti1IaVFpSAziCZWNzbNuZmnvw/i6CqLNdWfZY=
 github.com/jcmturner/rpc/v2 v2.0.3/go.mod h1:VUJYCIDm3PVOEHw8sgt091/20OJjskO/YJki3ELg/Hc=
-github.com/jinzhu/copier v0.4.0 h1:w3ciUoD19shMCRargcpm0cm91ytaBhDvuRpz1ODO/U8=
-github.com/jinzhu/copier v0.4.0/go.mod h1:DfbEm0FYsaqBcKcFuvmOZb218JkPGtvSHsKg8S8hyyg=
 github.com/jstemmer/go-junit-report v0.0.0-20190106144839-af01ea7f8024/go.mod h1:6v2b51hI/fHJwM22ozAgKL4VKDeJcHhJFhtBdhmNjmU=
 github.com/jstemmer/go-junit-report v0.9.1/go.mod h1:Brl9GWCQeLvo8nXZwPNNblvFj/XSXhF0NWZEnDohbsk=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=

internal/util/util.go

@@ -10,7 +10,6 @@ import (
 	"time"
 
 	"github.com/bodgit/tsig"
-	"github.com/jinzhu/copier"
 	"github.com/miekg/dns"
 )
 
@@ -37,10 +36,8 @@ type Exchanger interface {
 // TCP. If the existing network is configured to only use IPv4 or IPv6 then
 // the appropriate network is chosen to maintain this choice.
 func CopyDNSClient(dnsClient *dns.Client) (*dns.Client, error) {
-	client := new(dns.Client)
-	if err := copier.Copy(client, dnsClient); err != nil {
-		return nil, err
-	}
+	client := &dns.Client{}
+	*client = *dnsClient
 
 	switch client.Net {
 	case "tcp", "tcp4", "tcp6":

internal/util/util_test.go

@@ -9,6 +9,7 @@ import (
 	"github.com/bodgit/tsig/internal/util"
 	"github.com/miekg/dns"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 type FakeClient struct {
@@ -161,3 +162,43 @@ func TestCopyDNSClient(t *testing.T) {
 		})
 	}
 }
+
+type mockTsigProvider struct {
+	Name string
+}
+
+func (f mockTsigProvider) Generate(_ []byte, _ *dns.TSIG) ([]byte, error) {
+	return nil, nil
+}
+
+func (f mockTsigProvider) Verify(_ []byte, _ *dns.TSIG) error {
+	return nil
+}
+
+func TestCopyDNSClient_shallow_copy(t *testing.T) {
+	t.Parallel()
+
+	dnsClient := &dns.Client{
+		Net:          "udp",
+		TsigProvider: &mockTsigProvider{Name: "original"},
+	}
+
+	client, err := util.CopyDNSClient(dnsClient)
+	require.NoError(t, err)
+
+	client.TsigProvider = &mockTsigProvider{Name: "copy"}
+
+	originalProvider, ok := dnsClient.TsigProvider.(*mockTsigProvider)
+	require.True(t, ok)
+
+	assert.Equal(t, "original", originalProvider.Name)
+	assert.Equal(t, "udp", dnsClient.Net)
+	assert.Nil(t, dnsClient.TsigSecret)
+
+	copyProvider, ok := client.TsigProvider.(*mockTsigProvider)
+	require.True(t, ok)
+
+	assert.Equal(t, "copy", copyProvider.Name)
+	assert.Equal(t, "tcp", client.Net)
+	assert.NotNil(t, client.TsigSecret)
+}