Making the cache dictionary thread safe

Moq.AutoMock/AutoMocker.cs

@@ -114,6 +114,7 @@ public AutoMocker(MockBehavior mockBehavior, DefaultValue defaultValue, DefaultV
     /// The keys are the types used when resolving services.
     /// </summary>
     public IReadOnlyDictionary<Type, object?> ResolvedObjects
+        //NB: NonBlocking.ConcurrentDictionary GetEnumerator method returns a snapshot enumerator which is thread-safe
         => TypeMap?.ToDictionary(kvp => kvp.Key, kvp =>
         {
             return kvp.Value switch
@@ -123,7 +124,7 @@ public AutoMocker(MockBehavior mockBehavior, DefaultValue defaultValue, DefaultV
             };
         }) ?? new Dictionary<Type, object?>();
 
-    private Dictionary<Type, IInstance>? TypeMap
+    private NonBlocking.ConcurrentDictionary<Type, IInstance>? TypeMap
         => Resolvers.OfType<CacheResolver>().FirstOrDefault()?.TypeMap;
 
     private bool TryResolve(Type serviceType,
@@ -1054,7 +1055,7 @@ internal void CacheInstances(IEnumerable<(Type, IInstance)> instances)
         });
     }
 
-    private void WithTypeMap(Action<Dictionary<Type, IInstance>> onTypeMap)
+    private void WithTypeMap(Action<NonBlocking.ConcurrentDictionary<Type, IInstance>> onTypeMap)
     {
         if (TypeMap is { } typeMap)
         {

Moq.AutoMock/Moq.AutoMock.csproj

@@ -33,6 +33,7 @@
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
     <PackageReference Include="Moq" Version="4.18.2" />
+    <PackageReference Include="NonBlocking" Version="2.1.0" />
     <ProjectReference Include="../Generators/Generators.csproj">
       <OutputItemType>Analyzer</OutputItemType>
       <ReferenceOutputAssembly>false</ReferenceOutputAssembly>

Moq.AutoMock/Resolvers/CacheResolver.cs

@@ -1,18 +1,18 @@
-namespace Moq.AutoMock.Resolvers;
-
-/// <summary>
-/// Provides the cache used by AutoMocker.
-/// </summary>
-public class CacheResolver : IMockResolver
-{
-    internal Dictionary<Type, IInstance> TypeMap { get; } = new();
-
-    /// <inheritdoc />
-    public void Resolve(MockResolutionContext context)
-    {
-        if (TypeMap.TryGetValue(context.RequestType, out IInstance instance))
-        {
-            context.Value = instance;
-        }
-    }
-}
+namespace Moq.AutoMock.Resolvers;
+
+/// <summary>
+/// Provides the cache used by AutoMocker.
+/// </summary>
+public class CacheResolver : IMockResolver
+{
+    internal NonBlocking.ConcurrentDictionary<Type, IInstance> TypeMap { get; } = new();
+
+    /// <inheritdoc />
+    public void Resolve(MockResolutionContext context)
+    {
+        if (TypeMap.TryGetValue(context.RequestType, out IInstance instance))
+        {
+            context.Value = instance;
+        }
+    }
+}