Allow GetMock<IServiceProvider>() to return a mock instead of the AutoMocker instance

Moq.AutoMock.Tests/Resolvers/SelfResolverTests.cs

@@ -26,4 +26,15 @@ public void WhenRequestTypeIsIServiceProviderThenResolvesToAutoMockerInstance()
         Assert.IsTrue(context.ValueProvided);
         Assert.AreSame(mocker, context.Value);
     }
+
+    [TestMethod]
+    [Description("Issue 450")]
+    public void WhenServiceProviderIsRequestedAsMockThenItReturnsMockedServiceProvider()
+    {
+        var mocker = new AutoMocker();
+
+        var serviceProvider = mocker.GetMock<IServiceProvider>();
+
+        Assert.IsNotNull(serviceProvider);
+    }
 }

Moq.AutoMock/AutoMocker.cs

@@ -784,7 +784,7 @@ public Mock GetMock(Type serviceType, bool enablePrivate)
 
     private Mock GetMockImplementation(Type serviceType, bool enablePrivate)
     {
-        if (TryResolve(serviceType, new ObjectGraphContext(enablePrivate), out IInstance? instance, out bool noCache) &&
+        if (TryResolve(serviceType, new ObjectGraphContext(enablePrivate, isMockCreation:true), out IInstance? instance, out bool noCache) &&
             instance.IsMock)
         {
             if (!noCache && TypeMap is { } typeMap && !typeMap.ContainsKey(serviceType))

Moq.AutoMock/ObjectGraphContext.cs

@@ -12,13 +12,24 @@ public class ObjectGraphContext
     /// <summary>
     /// Creates an instance with binding flags set according to `enablePrivate`.
     /// </summary>
-    /// <param name="enablePrivate"></param>
+    /// <param name="enablePrivate">Enable private members</param>
     public ObjectGraphContext(bool enablePrivate)
     {
         BindingFlags = GetBindingFlags(enablePrivate);
         VisitedTypes = [];
     }
 
+    /// <summary>
+    /// Creates an instance with binding flags set according to `enablePrivate`.
+    /// </summary>
+    /// <param name="enablePrivate">Enable private members</param>
+    /// <param name="isMockCreation">Indicates if the object is for a mock instance.</param>
+    public ObjectGraphContext(bool enablePrivate, bool isMockCreation)
+        : this(enablePrivate)
+    {
+        IsMockCreation = isMockCreation;
+    }
+
     /// <summary>
     /// Creates a new instance, copying the values for the Binding flags and the Visited types.
     /// </summary>
@@ -46,6 +57,12 @@ public ObjectGraphContext(ObjectGraphContext context, ParameterInfo targetParame
         ParameterInfo = targetParameter ?? throw new ArgumentNullException(nameof(targetParameter));
     }
 
+    /// <summary>
+    /// Indicates if the requested operation is for creating a Mock instance.
+    /// This will will only be true for types requested through AutoMocker.GetMock methods.
+    /// </summary>
+    public bool IsMockCreation { get; }
+
     /// <summary>
     /// Flags passed to Mock constructor.
     /// </summary>

Moq.AutoMock/Resolvers/SelfResolver.cs

@@ -6,6 +6,16 @@
 public class SelfResolver : SimpleTypeResolver<AutoMocker>
 {
     /// <inheritdoc />
-    protected override AutoMocker GetValue(MockResolutionContext context)
+    public override void Resolve(MockResolutionContext context)
+    {
+        if (context.ObjectGraphContext.IsMockCreation)
+        {
+            return;
+        }
+        base.Resolve(context);
+    }
+
+    /// <inheritdoc />
+    protected override AutoMocker GetValue(MockResolutionContext context) 
         => context.AutoMocker;
 }

Moq.AutoMock/Resolvers/SimpleTypeResolver.cs

@@ -19,7 +19,7 @@ public abstract class SimpleTypeResolver<T> : IMockResolver
     protected bool IncludeInterfaces { get; set; } = true;
 
     /// <inheritdoc />
-    public void Resolve(MockResolutionContext context)
+    public virtual void Resolve(MockResolutionContext context)
     {
         if (context.RequestType == typeof(T) ||
             (IncludeBaseTypes && typeof(T).IsAssignableFrom(context.RequestType)) ||