check null safety

lib/domain/vo/contact.dart

@@ -1,12 +1,12 @@
 import 'package:fcs/domain/entities/setting.dart';
 
 class Contact {
-  String usaAddress;
-  String mmAddress;
-  String usaContactNumber;
-  String mmContactNumber;
-  String emailAddress;
-  String facebookLink;
+  String? usaAddress;
+  String? mmAddress;
+  String? usaContactNumber;
+  String? mmContactNumber;
+  String? emailAddress;
+  String? facebookLink;
 
   Contact({
     this.usaAddress,

lib/domain/vo/delivery_address.dart

@@ -1,13 +1,14 @@
 class DeliveryAddress {
-  String id;
-  String fullName;
-  String addressLine1;
-  String addressLine2;
-  String city;
-  String state;
-  String phoneNumber;
+  String? id;
+  String? fullName;
+  String? addressLine1;
+  String? addressLine2;
+  String? city;
+  String? state;
+  String? phoneNumber;
   bool isDefault;
-  String userID;
+  String? userID;
+
   DeliveryAddress(
       {this.id,
       this.fullName,

lib/domain/vo/message.dart

@@ -1,15 +1,15 @@
 import 'package:cloud_firestore/cloud_firestore.dart';
 
 class Message {
-  String id;
-  String message;
-  DateTime date;
-  String receiverID;
-  String receiverName;
-  String senderID;
-  String senderName;
-  String messageType;
-  String messageID;
+  String? id;
+  String? message;
+  DateTime? date;
+  String? receiverID;
+  String? receiverName;
+  String? senderID;
+  String? senderName;
+  String? messageType;
+  String? messageID;
 
   Message(
       {this.id,
@@ -21,11 +21,13 @@ class Message {
       this.senderName,
       this.messageType,
       this.messageID});
+
   bool fromToday() {
+    if (date == null) return false;
     var now = DateTime.now();
-    return date.day == now.day &&
-        date.month == now.month &&
-        date.year == now.year;
+    return date!.day == now.day &&
+        date!.month == now.month &&
+        date!.year == now.year;
   }
 
   Map<String, dynamic> toMap() {
@@ -36,9 +38,10 @@ class Message {
   }
 
   bool sameDay(Message another) {
-    return date.year == another.date.year &&
-        date.month == another.date.month &&
-        date.day == another.date.day;
+    if (date == null) return false;
+    return date!.year == another.date!.year &&
+        date!.month == another.date!.month &&
+        date!.day == another.date!.day;
   }
 
   factory Message.fromMap(Map<String, dynamic> map, String id) {
@@ -52,7 +55,7 @@ class Message {
       receiverName: map['receiver_name'],
       messageType: map['msg_type'],
       messageID: map['msg_id'],
-      date: date != null ? date.toDate() : null,
+      date: date.toDate(),
     );
   }
 }

lib/domain/vo/privilege.dart

@@ -1,20 +1,24 @@
 import 'package:fcs/domain/constants.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_icons_null_safety/flutter_icons_null_safety.dart';
 import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 
 class Privilege {
   String id;
-  String name;
-  String desc;
-  bool sysAdminOnly = true;
-  bool isChecked = false;
+  String? name;
+  String? desc;
+  bool? sysAdminOnly = true;
+  bool? isChecked = false;
 
-  IconData iconData;
+  IconData? iconData;
 
   Privilege(
-      {this.id, this.name, this.desc, this.isChecked, this.sysAdminOnly}) {
+      {required this.id,
+      this.name,
+      this.desc,
+      this.isChecked,
+      this.sysAdminOnly}) {
     if (this.id == privilege_admin) {
       iconData = MaterialCommunityIcons.account_tie;
     } else if (this.id == privilege_support) {

lib/domain/vo/radio.dart

@@ -1,5 +0,0 @@
-class RadioGroup {
-  String text;
-  int index;
-  RadioGroup({this.text, this.index});
-}

lib/domain/vo/shipment_status.dart

@@ -3,17 +3,21 @@ import 'package:cloud_firestore/cloud_firestore.dart';
 class ShipmentStatus {
   String status;
   DateTime date;
-  bool done;
-  String staffId;
-  String staffName;
+  bool? done;
+  String? staffId;
+  String? staffName;
   ShipmentStatus(
-      {this.status, this.date, this.done, this.staffId, this.staffName});
+      {required this.status,
+      required this.date,
+      this.done,
+      this.staffId,
+      this.staffName});
 
   factory ShipmentStatus.fromMap(Map<String, dynamic> map) {
     var _date = (map['date'] as Timestamp);
     return ShipmentStatus(
         status: map['status'],
-        date: _date == null ? null : _date.toDate(),
+        date: _date.toDate(),
         done: map['done'],
         staffId: map['staff_id'],
         staffName: map['staff_name']);

lib/domain/vo/status.dart

@@ -1,8 +1,7 @@
-
 class Status {
-  String status;
-  String message;
-  String errorCode;
+  String? status;
+  String? message;
+  String? errorCode;
   Status(this.status, this.message);
 
   Status.fromJson(Map<String, dynamic> json) {
@@ -10,4 +9,4 @@ class Status {
     message = json['message'];
     errorCode = json['error_code'];
   }
-}
+}

lib/domain/vo/term.dart

@@ -1,8 +1,8 @@
 import 'package:fcs/domain/entities/setting.dart';
 
 class Term {
-  String termEng;
-  String termMm;
+  String? termEng;
+  String? termMm;
 
   Term({this.termEng, this.termMm});