Implements .Clone() on top of flowed localized seed. #100.

Source/Bogus.Tests/Bogus.Tests.csproj

@@ -79,6 +79,7 @@
     </Reference>
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="CloneTests.cs" />
     <Compile Include="DataSetTests\AddressTest.cs" />
     <Compile Include="DataSetTests\CardTests.cs" />
     <Compile Include="DataSetTests\CommerceTest.cs" />

Source/Bogus.Tests/CloneTests.cs

@@ -0,0 +1,50 @@
+using FluentAssertions;
+using Xunit;
+
+namespace Bogus.Tests
+{
+   public class CloneTests : SeededTest
+   {
+      [Fact]
+      public void can_create_a_simple_clone()
+      {
+         var orderFaker = new Faker<Examples.Order>()
+            .UseSeed(88)
+            .RuleFor(o => o.OrderId, f => f.IndexVariable++)
+            .RuleFor(o => o.Quantity, f => f.Random.Number(1, 3))
+            .RuleFor(o => o.Item, f => f.Commerce.Product());
+
+         var clone = orderFaker.Clone();
+
+         var clonedOrder = clone.Generate();
+
+         var rootOrder = orderFaker.Generate();
+
+         clonedOrder.ShouldBeEquivalentTo(rootOrder);
+      }
+
+      [Fact]
+      public void clone_has_different_rules()
+      {
+         var rootFaker = new Faker<Examples.Order>()
+            .UseSeed(88)
+            .RuleFor(o => o.OrderId, f => f.IndexVariable++)
+            .RuleFor(o => o.Quantity, f => f.Random.Number(1, 3))
+            .RuleFor(o => o.Item, f => f.Commerce.Product());
+
+         var cloneFaker = rootFaker.Clone()
+            .RuleFor(o => o.Quantity, f => f.Random.Number(4, 6));
+
+         var rootOrder = rootFaker.Generate();
+         var clonedOrder = cloneFaker.Generate();
+
+         rootOrder.Quantity.Should()
+            .BeGreaterOrEqualTo(1).And
+            .BeLessOrEqualTo(3);
+
+         clonedOrder.Quantity.Should()
+            .BeGreaterOrEqualTo(4).And
+            .BeLessOrEqualTo(6);
+      }
+   }
+}

Source/Bogus.Tests/GitHubIssues/Issue100.cs

@@ -147,26 +147,27 @@ public void complex_faker_t_test()
          CheckSequence(items);
       }
 
-      //[Fact]
-      //public void parallel_determinism()
-      //{
-      //   var orderFaker = new Faker<Examples.Order>()
-      //      .RuleFor(o => o.OrderId, f => f.IndexVariable++)
-      //      .RuleFor(o => o.Quantity, f => f.Random.Number(1, 3))
-      //      .RuleFor(o => o.Item, f => f.Commerce.Product());
-
-      //   var orders = ParallelEnumerable.Range(1, 5)
-      //      .Select(threadId =>
-      //         orderFaker
-      //            .UseSeed(88)
-      //            .Generate(4).ToArray()
-      //      ).ToArray();
-
-      //   foreach( var orderOfFour in orders )
-      //   {
-      //      CheckSequence(orderOfFour);
-      //   }
-      //}
+      [Fact]
+      public void parallel_determinism()
+      {
+         var orderFaker = new Faker<Examples.Order>()
+            .RuleFor(o => o.OrderId, f => f.IndexVariable++)
+            .RuleFor(o => o.Quantity, f => f.Random.Number(1, 3))
+            .RuleFor(o => o.Item, f => f.Commerce.Product());
+
+         var orders = ParallelEnumerable.Range(1, 5)
+            .Select(threadId =>
+               orderFaker
+                  .Clone()
+                  .UseSeed(88)
+                  .Generate(4).ToArray()
+            ).ToArray();
+
+         foreach( var orderOfFour in orders )
+         {
+            CheckSequence(orderOfFour);
+         }
+      }
 
       private void CheckSequence(Examples.Order[] items)
       {

Source/Bogus/Faker[T].cs

@@ -26,8 +26,62 @@ public class Faker<T> : ILocaleAware, IRuleSet<T> where T : class
         protected internal Dictionary<string, bool> StrictModes = new Dictionary<string, bool>();
         protected internal bool? IsValid;
         protected internal string currentRuleSet = Default;
+        protected internal int? localSeed; // if null, the global Randomizer.Seed is used.
 #pragma warning restore 1591
 
+      /// <summary>
+      /// Clones the internal state of a Faker[T] into a new Faker[T] so that
+      /// both are isolated from each other. The clone will have internal state
+      /// reset as if .Generate() was never
+      /// </summary>
+      public Faker<T> Clone()
+      {
+         var clone = new Faker<T>(this.Locale, this.binder);
+
+         //copy internal state.
+         //strict modes.
+         foreach( var root in this.StrictModes )
+         {
+            clone.StrictModes.Add(root.Key, root.Value);
+         }
+
+         //ignores
+         foreach( var root in this.Ignores )
+         {
+            foreach( var str in root.Value )
+            {
+               clone.Ignores.Add(root.Key, str);
+            }
+         }
+
+         //create actions
+         foreach( var root in this.CreateActions )
+         {
+            clone.CreateActions[root.Key] = root.Value;
+         }
+         //finalize actions
+         foreach( var root in this.FinalizeActions )
+         {
+            clone.FinalizeActions.Add(root.Key, root.Value);
+         }
+
+         //actions
+         foreach( var root in this.Actions )
+         {
+            foreach( var kv in root.Value )
+            {
+               clone.Actions.Add(root.Key, kv.Key, kv.Value);
+            }
+         }
+
+         if( localSeed.HasValue )
+         {
+            clone.UseSeed(localSeed.Value);
+         }
+
+         return clone;
+      }
+
         /// <summary>
         /// The current locale.
         /// </summary>
@@ -68,8 +122,8 @@ public Faker(string locale = "en", IBinder binder = null)
         /// <para name="seed">The seed value to use within this Faker[T] instance.</para>
         public virtual Faker<T> UseSeed(int seed)
         {
-           var r = new Randomizer(seed);
-           this.FakerHub.Random = r;
+           this.localSeed = seed;
+           this.FakerHub.Random = new Randomizer(seed);
            return this;
         }