#59 Remove the need for shuffle in UuidUtil.mathRNG

lib/uuid_util.dart

@@ -2,32 +2,34 @@
 library uuid_util;
 
 import 'dart:math';
-
 import 'dart:typed_data';
 
 class UuidUtil {
-  /// Math.Random()-based RNG. All platforms, fast, not cryptographically strong. Optional Seed passable.
-  static Uint8List mathRNG({int seed = -1}) {
-    var b = Uint8List(16);
+  static final _random = Random();
+  static final _secureRandom = Random.secure();
 
-    var rand = (seed == -1) ? Random() : Random(seed);
+  /// Math.Random()-based RNG. All platforms, fast, not cryptographically
+  /// strong. Optional Seed passable.
+  static Uint8List mathRNG({int seed = -1}) {
+    final b = Uint8List(16);
+    final rand = (seed == -1) ? _random : Random(seed);
 
     for (var i = 0; i < 16; i++) {
       b[i] = rand.nextInt(256);
     }
 
-    (seed == -1) ? b.shuffle() : b.shuffle(Random(seed));
-
     return b;
   }
 
-  /// Crypto-Strong RNG. All platforms, unknown speed, cryptographically strong (theoretically)
+  /// Crypto-Strong RNG. All platforms, unknown speed, cryptographically strong
+  /// (theoretically)
   static Uint8List cryptoRNG() {
-    var b = Uint8List(16);
-    var rand = Random.secure();
+    final b = Uint8List(16);
+
     for (var i = 0; i < 16; i++) {
-      b[i] = rand.nextInt(256);
+      b[i] = _secureRandom.nextInt(256);
     }
+
     return b;
   }
 }

test/uuid_test.dart

@@ -118,7 +118,7 @@ void main() {
         'rng': UuidUtil.mathRNG,
         'namedArgs': Map.fromIterables([const Symbol('seed')], [1])
       });
-      var u1 = '4dff2ea7-7bc8-4fea-8da0-a4993073bdb3';
+      var u1 = 'a473ff7b-b3cd-4899-a04d-ea0fbd30a72e';
       expect(u0, equals(u1));
     });
 
@@ -129,7 +129,7 @@ void main() {
         'namedArgs': Map.fromIterables([const Symbol('seed')], [1])
       });
 
-      var u1 = '4dff2ea7-7bc8-4fea-8da0-a4993073bdb3';
+      var u1 = 'a473ff7b-b3cd-4899-a04d-ea0fbd30a72e';
       expect(Uuid.unparse(buffer), equals(u1));
     });