diff --git a/go.mod b/go.mod
index 9d0f227..8ee477f 100644
--- a/go.mod
+++ b/go.mod
@@ -1,4 +1,4 @@
-module cloudflare-ddns
+module github.com/mkelcik/cloudflare-ddns-update
 
 go 1.20
 
diff --git a/internal/config_test.go b/internal/config_test.go
new file mode 100644
index 0000000..0811ad0
--- /dev/null
+++ b/internal/config_test.go
@@ -0,0 +1,74 @@
+package internal
+
+import (
+	"testing"
+	"time"
+)
+
+func TestConfig_Validate(t *testing.T) {
+	type fields struct {
+		DnsRecordsToCheck   []string
+		PublicIpResolverTag string
+		ApiToken            string
+		CloudflareZone      string
+		OnChangeComment     string
+		CheckInterval       time.Duration
+	}
+	tests := []struct {
+		name    string
+		fields  fields
+		wantErr bool
+	}{
+		{
+			name: "all ok",
+			fields: fields{
+				DnsRecordsToCheck: []string{"domain1", "domain2"},
+				ApiToken:          "some_api_key",
+				CloudflareZone:    "some_zone",
+			},
+			wantErr: false,
+		},
+		{
+			name: "empty api token",
+			fields: fields{
+				DnsRecordsToCheck: []string{"domain1", "domain2"},
+				ApiToken:          "",
+				CloudflareZone:    "some_zone",
+			},
+			wantErr: true,
+		},
+		{
+			name: "empty check dns record",
+			fields: fields{
+				DnsRecordsToCheck: []string{},
+				ApiToken:          "",
+				CloudflareZone:    "some_zone",
+			},
+			wantErr: true,
+		},
+		{
+			name: "empty zone",
+			fields: fields{
+				DnsRecordsToCheck: []string{"domain1", "domain2"},
+				ApiToken:          "some_api_key",
+				CloudflareZone:    "",
+			},
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			c := Config{
+				DnsRecordsToCheck:   tt.fields.DnsRecordsToCheck,
+				PublicIpResolverTag: tt.fields.PublicIpResolverTag,
+				ApiToken:            tt.fields.ApiToken,
+				CloudflareZone:      tt.fields.CloudflareZone,
+				OnChangeComment:     tt.fields.OnChangeComment,
+				CheckInterval:       tt.fields.CheckInterval,
+			}
+			if err := c.Validate(); (err != nil) != tt.wantErr {
+				t.Errorf("Validate() error = %v, wantErr %v", err, tt.wantErr)
+			}
+		})
+	}
+}
diff --git a/internal/helpers.go b/internal/helpers.go
index d2fa19e..e287078 100644
--- a/internal/helpers.go
+++ b/internal/helpers.go
@@ -5,7 +5,9 @@ import "strings"
 func parseDNSToCheck(data string) []string {
 	out := make([]string, 0, strings.Count(data, ",")+1)
 	for _, dns := range strings.Split(data, ",") {
-		out = append(out, strings.TrimSpace(dns))
+		if w := strings.TrimSpace(dns); w != "" {
+			out = append(out, w)
+		}
 	}
 	return out
 }
diff --git a/internal/helpers_test.go b/internal/helpers_test.go
new file mode 100644
index 0000000..d13168d
--- /dev/null
+++ b/internal/helpers_test.go
@@ -0,0 +1,83 @@
+package internal
+
+import (
+	"reflect"
+	"testing"
+)
+
+func Test_parseDNSToCheck(t *testing.T) {
+	type args struct {
+		data string
+	}
+	tests := []struct {
+		name string
+		args args
+		want []string
+	}{
+		{
+			name: "test parsing",
+			args: args{
+				data: "word1,word2,",
+			},
+			want: []string{"word1", "word2"},
+		},
+		{
+			name: "test parsing with spaces",
+			args: args{
+				data: " word1, word2 ",
+			},
+			want: []string{"word1", "word2"},
+		},
+		{
+			name: "test parsing with empty word",
+			args: args{
+				data: " word1, word2 ,",
+			},
+			want: []string{"word1", "word2"},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := parseDNSToCheck(tt.args.data); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("parseDNSToCheck() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestContains(t *testing.T) {
+	type args[T comparable] struct {
+		haystack []T
+		needle   T
+	}
+	type testCase[T comparable] struct {
+		name string
+		args args[T]
+		want bool
+	}
+	tests := []testCase[string]{
+		{
+			name: "yes",
+			args: args[string]{
+				haystack: []string{"w1", "w2"},
+				needle:   "w1",
+			},
+			want: true,
+		},
+		{
+			name: "no",
+			args: args[string]{
+				haystack: []string{"w1", "w2"},
+				needle:   "w3",
+			},
+			want: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := Contains(tt.args.haystack, tt.args.needle); got != tt.want {
+				t.Errorf("Contains() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
diff --git a/main.go b/main.go
index 394ec15..f66eaff 100644
--- a/main.go
+++ b/main.go
@@ -9,9 +9,9 @@ import (
 	"syscall"
 	"time"
 
-	"cloudflare-ddns/internal"
-	"cloudflare-ddns/public_resolvers"
 	"github.com/cloudflare/cloudflare-go"
+	"github.com/mkelcik/cloudflare-ddns-update/internal"
+	"github.com/mkelcik/cloudflare-ddns-update/public_resolvers"
 )
 
 type PublicIpResolver interface {
@@ -44,6 +44,8 @@ func main() {
 		log.Fatal(err)
 	}
 
+	log.Printf("Current public ip `%s`", currentPublicIP)
+
 	api, err := cloudflare.NewWithAPIToken(config.ApiToken)
 	if err != nil {
 		log.Fatal(err)