[Core] Add null fallback for all string entity fields

We are safe... for now.

Author: Wesley-Young

Lagrange.Core/Common/Entity/BotFriend.cs

@@ -4,19 +4,19 @@ public class BotFriend(long uin, string nickname, string uid, string remarks, st
 {
     public override long Uin { get; } = uin;
 
-    public override string Nickname { get; } = nickname;
+    public override string Nickname { get; } = nickname ?? string.Empty;
 
-    public override string Uid { get; } = uid;
+    public override string Uid { get; } = uid ?? string.Empty;
 
     public int Age { get; init; }
 
     public BotGender Gender { get; init; }
 
-    public string Remarks { get; } = remarks;
+    public string Remarks { get; } = remarks ?? string.Empty;
 
-    public string PersonalSign { get; } = personalSign;
+    public string PersonalSign { get; } = personalSign ?? string.Empty;
 
-    public string Qid { get; } = qid;
+    public string Qid { get; } = qid ?? string.Empty;
 
     public BotFriendCategory Category { get; } = category;
 }

Lagrange.Core/Common/Entity/BotFriendCategory.cs

@@ -4,7 +4,7 @@ public class BotFriendCategory(int id, string name, int count, int sortId)
 {
     public int Id { get; } = id;
 
-    public string Name { get; } = name;
+    public string Name { get; } = name ?? string.Empty;
 
     public int Count { get; } = count;
 

Lagrange.Core/Common/Entity/BotGroup.cs

@@ -12,7 +12,7 @@ public class BotGroup(
 {
     public long GroupUin { get; } = groupUin;
 
-    public string GroupName { get; } = groupName;
+    public string GroupName { get; } = groupName ?? string.Empty;
 
     public int MemberCount { get; } = memberCount;
 

Lagrange.Core/Common/Entity/BotGroupMember.cs

@@ -17,9 +17,9 @@ public class BotGroupMember(
 
     public override long Uin { get; } = uin;
 
-    public override string Uid { get; } = uid;
+    public override string Uid { get; } = uid ?? string.Empty;
 
-    public override string Nickname { get; } = nickname;
+    public override string Nickname { get; } = nickname ?? string.Empty;
 
     public int Age { get; init; }
 

Lagrange.Core/Common/Entity/BotStranger.cs

@@ -4,9 +4,9 @@ public class BotStranger(long uin, string nickname, string uid) : BotContact
 {
     public override long Uin { get; } = uin;
 
-    public override string Nickname { get; } = nickname;
+    public override string Nickname { get; } = nickname ?? string.Empty;
 
-    public override string Uid { get; } = uid;
+    public override string Uid { get; } = uid ?? string.Empty;
 
     public long Source { get; init; }
 }