Fix for parallel generation

src/AutoFakerBinder.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Collections;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
-using System.Runtime.InteropServices;
 using Soenneker.Extensions.FieldInfo;
 using Soenneker.Reflection.Cache.Constructors;
 using Soenneker.Reflection.Cache.Extensions;
@@ -26,8 +26,8 @@ public class AutoFakerBinder : IAutoFakerBinder
 {
     internal readonly GeneratorService GeneratorService;
 
-    private readonly Dictionary<CachedType, List<AutoMember>> _autoMembersCache = [];
-    private readonly Dictionary<CachedType, CachedConstructor> _constructorsCache = [];
+    private readonly ConcurrentDictionary<CachedType, List<AutoMember>> _autoMembersCache = [];
+    private readonly ConcurrentDictionary<CachedType, CachedConstructor> _constructorsCache = [];
 
     public AutoFakerBinder()
     {

test/Soenneker.Utils.AutoBogus.Tests/AutoFakerParallelTests.cs

@@ -0,0 +1,56 @@
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Soenneker.Utils.AutoBogus.Tests.Dtos.Simple;
+using Xunit;
+
+namespace Soenneker.Utils.AutoBogus.Tests;
+
+public class AutoFakerParallelTests
+{
+    [Fact]
+    public void Generate_with_ParallelExecution()
+    {
+        // Arrange
+        const int numberOfTasks = 1000;
+        var results = new ConcurrentBag<TestClassWithSimpleProperties>();
+
+        var autoFaker = new AutoFaker();
+
+        // Act
+        Parallel.For(0, numberOfTasks, _ =>
+        {
+            var fakeModel = autoFaker.Generate<TestClassWithSimpleProperties>();
+            results.Add(fakeModel);
+        });
+
+        // Assert
+        Assert.Equal(numberOfTasks, results.Count);
+
+        List<int> ids = results.Select(x => x.Id).ToList();
+        Assert.Equal(ids.Count, ids.Distinct().Count()); // Ensure IDs are unique
+    }
+
+    [Fact]
+    public async Task Generate_with_ParallelExecutionTasks()
+    {
+        // Arrange
+        const int numberOfTasks = 1000;
+
+        var autoFaker = new AutoFaker();
+
+        // Act
+        Task<TestClassWithSimpleProperties>[] tasks = Enumerable.Range(0, numberOfTasks)
+            .Select(_ => Task.Run(() => autoFaker.Generate<TestClassWithSimpleProperties>()))
+            .ToArray();
+
+        TestClassWithSimpleProperties[] results = await Task.WhenAll(tasks);
+
+        // Assert
+        Assert.Equal(numberOfTasks, results.Length);
+
+        List<int> ids = results.Select(x => x.Id).ToList();
+        Assert.Equal(ids.Count, ids.Distinct().Count()); // Ensure IDs are unique
+    }
+}

test/Soenneker.Utils.AutoBogus.Tests/Dtos/Simple/TestClassWithSimpleProperties.cs

@@ -0,0 +1,13 @@
+using System;
+
+namespace Soenneker.Utils.AutoBogus.Tests.Dtos.Simple
+{
+    internal class TestClassWithSimpleProperties
+    {
+        public int Id { get; set; }
+
+        public string Name { get; set; }
+
+        public DateTime CreatedAt { get; set; }
+    }
+}