From 48b6bc9a24367962b1a97e5d6647c51e6f42dbb1 Mon Sep 17 00:00:00 2001
From: svn37 <svngit@proton.me>
Date: Wed, 10 Jan 2024 13:54:12 +0400
Subject: [PATCH] add more informative error for empty values (#40)

---
 ip/ip.go         | 4 +++-
 ip/ip_test.go    | 3 ++-
 ip/ip_v4.go      | 2 +-
 ip/ip_v6.go      | 2 +-
 ip/ip_v6_test.go | 3 ++-
 5 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/ip/ip.go b/ip/ip.go
index ef4d5cd..ec95c9d 100644
--- a/ip/ip.go
+++ b/ip/ip.go
@@ -7,6 +7,8 @@ import (
 	"fmt"
 )
 
+var ErrEmptyValue = errors.New("ip address cannot be empty")
+
 type IP struct {
 	v4   IPv4
 	v6   IPv6
@@ -84,7 +86,7 @@ func (ip IP) IsIPv6() bool {
 
 func FromString(value string) (IP, error) {
 	if value == "" {
-		return IP{}, fmt.Errorf("empty value")
+		return IP{}, ErrEmptyValue
 	}
 
 	var v4Addr, err = V4FromString(value)
diff --git a/ip/ip_test.go b/ip/ip_test.go
index b70dd4b..0a684e8 100644
--- a/ip/ip_test.go
+++ b/ip/ip_test.go
@@ -79,7 +79,7 @@ func TestIP_Value(t *testing.T) {
 			name: "IPv6",
 			ip: IP{
 				isV6: true,
-				v6:   IPv6("2001:0db8:85a3:0000:0000:8a2e:0370:7334"),
+				v6:   IPv6("2001:db8:85a3::8a2e:370:7334"),
 				raw:  "2001:0db8:85a3:0000:0000:8a2e:0370:7334",
 			},
 			wantValue: "2001:0db8:85a3:0000:0000:8a2e:0370:7334",
@@ -302,6 +302,7 @@ func TestParseIPFromString(t *testing.T) {
 				t.Errorf("ParseIPFromString() error = %v, wantErr %v", err, tt.wantErr)
 				return
 			}
+
 			if got != tt.wantValue {
 				t.Errorf("ParseIPFromString() got = %v, want %v", got, tt.wantValue)
 			}
diff --git a/ip/ip_v4.go b/ip/ip_v4.go
index e73ae28..a69a4f6 100644
--- a/ip/ip_v4.go
+++ b/ip/ip_v4.go
@@ -52,7 +52,7 @@ func (ip IPv4) String() string {
 
 func V4FromString(value string) (IPv4, error) {
 	if value == "" {
-		return "", fmt.Errorf("empty value")
+		return "", ErrEmptyValue
 	}
 
 	var addr, err = netip.ParseAddr(value)
diff --git a/ip/ip_v6.go b/ip/ip_v6.go
index 606f1d2..dcf6ae2 100644
--- a/ip/ip_v6.go
+++ b/ip/ip_v6.go
@@ -52,7 +52,7 @@ func (ip IPv6) String() string {
 
 func V6FromString(value string) (IPv6, error) {
 	if value == "" {
-		return "", fmt.Errorf("empty value")
+		return "", ErrEmptyValue
 	}
 
 	var addr, err = netip.ParseAddr(value)
diff --git a/ip/ip_v6_test.go b/ip/ip_v6_test.go
index d264fb3..b037272 100644
--- a/ip/ip_v6_test.go
+++ b/ip/ip_v6_test.go
@@ -3,6 +3,7 @@ package ip
 import (
 	"database/sql/driver"
 	"encoding/json"
+	"fmt"
 	"reflect"
 	"testing"
 )
@@ -83,7 +84,7 @@ func TestIPv6_UnmarshalJSON(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			var ipv6 IPv6
-			err := json.Unmarshal([]byte(tt.ip), &ipv6)
+			err := json.Unmarshal([]byte(fmt.Sprintf(`"%s"`, tt.ip)), &ipv6)
 			if (err != nil) != tt.wantErr {
 				t.Errorf("UnmarshalJSON() error = %v, wantErr %v", err, tt.wantErr)
 			}