add EncryptionType test

@@ -16,15 +16,16 @@ enum EncryptionType {
 
   factory EncryptionType.fromRawValue(int value) {
     switch (value) {
+      case 0:
+        return EncryptionType.none;
       case 1:
         return EncryptionType.open;
       case 2:
         return EncryptionType.wpa;
       case 3:
         return EncryptionType.wep;
-      case 0:
       default:
-        return EncryptionType.none;
+        throw ArgumentError.value(value, 'value', 'Invalid raw value.');
     }
   }
 

+import 'package:flutter_test/flutter_test.dart';
+import 'package:mobile_scanner/src/enums/encryption_type.dart';
+
+void main() {
+  group('$EncryptionType tests', () {
+    test('can be created from raw value', () {
+      const values = <int, EncryptionType>{
+        0: EncryptionType.none,
+        1: EncryptionType.open,
+        2: EncryptionType.wpa,
+        3: EncryptionType.wep,
+      };
+
+      for (final MapEntry<int, EncryptionType> entry in values.entries) {
+        final EncryptionType result = EncryptionType.fromRawValue(entry.key);
+
+        expect(result, entry.value);
+      }
+    });
+
+    test('invalid raw value throws argument error', () {
+      const int negative = -1;
+      const int outOfRange = 4;
+
+      expect(() => EncryptionType.fromRawValue(negative), throwsArgumentError);
+      expect(() => EncryptionType.fromRawValue(outOfRange), throwsArgumentError);
+    });
+
+    test('can be converted to raw value', () {
+      const values = <EncryptionType, int>{
+        EncryptionType.none: 0,
+        EncryptionType.open: 1,
+        EncryptionType.wpa: 2,
+        EncryptionType.wep: 3,
+      };
+
+      for (final MapEntry<EncryptionType, int> entry in values.entries) {
+        final int result = entry.key.rawValue;
+
+        expect(result, entry.value);
+      }
+    });
+  });
+}