feat: emit nested-mock TODO across all migration rewrite sites

Source/Mockolate.Migration.Analyzers.CodeFixers/MoqCodeFixProvider.cs

@@ -523,7 +523,8 @@ private static Dictionary<InvocationExpressionSyntax, InvocationExpressionSyntax
 					mockAccess,
 					methodNameSyntax);
 				replacement = SyntaxFactory.InvocationExpression(methodAccess, transformedArgs)
-					.WithTriviaFrom(invocation);
+					.WithTriviaFrom(invocation)
+					.WithLeadingTrivia(BuildNestedMockTodoTrivia(invocation, navChain));
 			}
 
 			result[invocation] = replacement;
@@ -624,6 +625,7 @@ private static Dictionary<InvocationExpressionSyntax, MemberAccessExpressionSynt
 			SimpleNameSyntax propertyNameSyntax = lambdaMemberAccess.Name;
 
 			MemberAccessExpressionSyntax replacement;
+			ExpressionSyntax? navChainForTodo = null;
 			if (navigationChain.Count == 0)
 			{
 				// Direct setup: mock.Mock.Setup.Property
@@ -664,9 +666,16 @@ private static Dictionary<InvocationExpressionSyntax, MemberAccessExpressionSynt
 					SyntaxKind.SimpleMemberAccessExpression,
 					setupAccess,
 					propertyNameSyntax);
+				navChainForTodo = navChain;
+			}
+
+			MemberAccessExpressionSyntax withTrivia = replacement.WithTriviaFrom(invocation);
+			if (navChainForTodo is not null)
+			{
+				withTrivia = withTrivia.WithLeadingTrivia(BuildNestedMockTodoTrivia(invocation, navChainForTodo));
 			}
 
-			result[invocation] = replacement.WithTriviaFrom(invocation);
+			result[invocation] = withTrivia;
 		}
 
 		return result;
@@ -730,6 +739,7 @@ private static Dictionary<InvocationExpressionSyntax, InvocationExpressionSyntax
 			SimpleNameSyntax propertyNameSyntax = lambdaMemberAccess.Name;
 
 			ExpressionSyntax propertyAccess;
+			ExpressionSyntax? navChainForTodo = null;
 			if (navigationChain.Count == 0)
 			{
 				MemberAccessExpressionSyntax mockAccess = SyntaxFactory.MemberAccessExpression(
@@ -768,6 +778,7 @@ private static Dictionary<InvocationExpressionSyntax, InvocationExpressionSyntax
 					SyntaxKind.SimpleMemberAccessExpression,
 					setupAccess,
 					propertyNameSyntax);
+				navChainForTodo = navChain;
 			}
 
 			InvocationExpressionSyntax replacement;
@@ -795,6 +806,11 @@ private static Dictionary<InvocationExpressionSyntax, InvocationExpressionSyntax
 					.WithTriviaFrom(invocation);
 			}
 
+			if (navChainForTodo is not null)
+			{
+				replacement = replacement.WithLeadingTrivia(BuildNestedMockTodoTrivia(invocation, navChainForTodo));
+			}
+
 			result[invocation] = replacement;
 		}
 
@@ -836,14 +852,17 @@ private static Dictionary<InvocationExpressionSyntax, InvocationExpressionSyntax
 			// because Mockolate infers them during code generation.
 			// Reuse the original dot token to preserve leading trivia (e.g. newline + indent
 			// when .Callback is written on its own line).
+			// Only set trailing trivia from invocation — applying full WithTriviaFrom would
+			// clobber leading trivia on rebuiltReceiver's first token, which may carry a
+			// nested-mock TODO comment attached to the migrated setup.
 			InvocationExpressionSyntax replacement = SyntaxFactory.InvocationExpression(
 					SyntaxFactory.MemberAccessExpression(
 						SyntaxKind.SimpleMemberAccessExpression,
 						rebuiltReceiver!,
 						memberAccess.OperatorToken,
 						SyntaxFactory.IdentifierName("Do")),
 					invocation.ArgumentList)
-				.WithTriviaFrom(invocation);
+				.WithTrailingTrivia(invocation.GetTrailingTrivia());
 
 			result[invocation] = replacement;
 		}
@@ -955,6 +974,7 @@ private static Dictionary<InvocationExpressionSyntax, InvocationExpressionSyntax
 				methodParameterCount);
 
 			InvocationExpressionSyntax baseInvocation;
+			ExpressionSyntax? navChainForTodo = null;
 			if (navigationChain.Count == 0)
 			{
 				MemberAccessExpressionSyntax mockAccess = SyntaxFactory.MemberAccessExpression(
@@ -995,6 +1015,7 @@ private static Dictionary<InvocationExpressionSyntax, InvocationExpressionSyntax
 					verifyAccess,
 					methodNameSyntax);
 				baseInvocation = SyntaxFactory.InvocationExpression(methodAccess, transformedArgs);
+				navChainForTodo = navChain;
 			}
 
 			InvocationExpressionSyntax replacement;
@@ -1020,6 +1041,11 @@ private static Dictionary<InvocationExpressionSyntax, InvocationExpressionSyntax
 					.WithTriviaFrom(invocation);
 			}
 
+			if (navChainForTodo is not null)
+			{
+				replacement = replacement.WithLeadingTrivia(BuildNestedMockTodoTrivia(invocation, navChainForTodo));
+			}
+
 			result[invocation] = replacement;
 		}
 
@@ -1145,6 +1171,11 @@ private static Dictionary<InvocationExpressionSyntax, InvocationExpressionSyntax
 				.WithTriviaFrom(invocation)
 				: atLeastOnceFallback.WithTriviaFrom(invocation);
 
+			if (navigationChain.Count > 0)
+			{
+				replacement = replacement.WithLeadingTrivia(BuildNestedMockTodoTrivia(invocation, receiver));
+			}
+
 			result[invocation] = replacement;
 		}
 
@@ -1279,6 +1310,11 @@ private static Dictionary<InvocationExpressionSyntax, InvocationExpressionSyntax
 				.WithTriviaFrom(invocation)
 				: atLeastOnceFallback.WithTriviaFrom(invocation);
 
+			if (navigationChain.Count > 0)
+			{
+				replacement = replacement.WithLeadingTrivia(BuildNestedMockTodoTrivia(invocation, receiver));
+			}
+
 			result[invocation] = replacement;
 		}
 
@@ -1796,6 +1832,24 @@ private static UsingDirectiveSyntax BuildUsingDirective(CompilationUnitSyntax co
 		return SyntaxFactory.UsingDirective(name);
 	}
 
+	private static SyntaxTriviaList BuildNestedMockTodoTrivia(SyntaxNode anchor, ExpressionSyntax navigationRoot)
+	{
+		SyntaxTriviaList existing = anchor.GetLeadingTrivia();
+		SyntaxTrivia indent = existing.LastOrDefault(t => t.IsKind(SyntaxKind.WhitespaceTrivia));
+		string endOfLine = DetectLineEnding(anchor.SyntaxTree.GetRoot());
+		return existing
+			.Add(SyntaxFactory.Comment(
+				$"// TODO(MockolateM001): register the nested '{navigationRoot}' chain explicitly in the mock setup (Mockolate doesn't auto-mock recursively)"))
+			.Add(SyntaxFactory.EndOfLine(endOfLine))
+			.Add(indent);
+	}
+
+	private static string DetectLineEnding(SyntaxNode root) =>
+		root.DescendantTrivia(descendIntoTrivia: true)
+			.Where(t => t.IsKind(SyntaxKind.EndOfLineTrivia))
+			.Select(t => t.ToFullString())
+			.FirstOrDefault(s => s.Length > 0) ?? "\n";
+
 	private static TypeSyntax? GetTypeArgumentFromSemanticModel(
 		SemanticModel? semanticModel,
 		ExpressionSyntax expressionSyntax,

Source/Mockolate.Migration.Analyzers.CodeFixers/NSubstituteCodeFixProvider.cs

@@ -318,7 +318,7 @@ private static Dictionary<SyntaxNode, SyntaxNode> FindAndBuildSetupReplacements(
 
 				if (outerReplacement is not null)
 				{
-					outerReplacement = ApplySetupTrivia(outerReplacement, outerInvocation,
+					outerReplacement = ApplyTodoTrivia(outerReplacement, outerInvocation,
 						isNested ? targetMemberAccess.Expression : null, callInfoTodoNeeded);
 					result[outerInvocation] = outerReplacement;
 				}
@@ -363,7 +363,7 @@ private static Dictionary<SyntaxNode, SyntaxNode> FindAndBuildSetupReplacements(
 
 				if (outerPropertyReplacement is not null)
 				{
-					outerPropertyReplacement = ApplySetupTrivia(outerPropertyReplacement, outerInvocation,
+					outerPropertyReplacement = ApplyTodoTrivia(outerPropertyReplacement, outerInvocation,
 						isNestedProperty ? targetPropertyAccess.Expression : null, propertyCallInfoTodoNeeded);
 					result[outerInvocation] = outerPropertyReplacement;
 				}
@@ -427,28 +427,30 @@ private static (InvocationExpressionSyntax effectiveOuter, bool callInfoTodoNeed
 	}
 
 	/// <summary>
-	///     Combines the nested-mock and CallInfo TODO comments onto a single setup replacement when both apply.
-	///     Either flag may be inactive; if neither is active, the replacement is returned untouched.
+	///     Layers the nested-mock and/or CallInfo TODO comments onto a migrated replacement. Called from
+	///     every rewrite path that can produce these TODOs — setup-call, setup-property, method verify,
+	///     property verify, and event raise. Either flag may be inactive; if neither is active, the
+	///     replacement is returned untouched.
 	/// </summary>
-	private static InvocationExpressionSyntax ApplySetupTrivia(InvocationExpressionSyntax replacement,
-		InvocationExpressionSyntax outerInvocation, ExpressionSyntax? nestedNavigationRoot, bool callInfoTodoNeeded)
+	private static InvocationExpressionSyntax ApplyTodoTrivia(InvocationExpressionSyntax replacement,
+		SyntaxNode anchor, ExpressionSyntax? nestedNavigationRoot, bool callInfoTodoNeeded)
 	{
 		if (nestedNavigationRoot is null && !callInfoTodoNeeded)
 		{
 			return replacement;
 		}
 
-		SyntaxTriviaList trivia = outerInvocation.GetLeadingTrivia();
+		SyntaxTriviaList trivia = anchor.GetLeadingTrivia();
 		if (nestedNavigationRoot is not null)
 		{
-			trivia = AppendTodoComment(trivia, outerInvocation,
-				$"// TODO: register the nested '{nestedNavigationRoot}' chain explicitly in the mock setup (Mockolate doesn't auto-mock recursively)");
+			trivia = AppendTodoComment(trivia, anchor,
+				$"// TODO(MockolateM002): register the nested '{nestedNavigationRoot}' chain explicitly in the mock setup (Mockolate doesn't auto-mock recursively)");
 		}
 
 		if (callInfoTodoNeeded)
 		{
-			trivia = AppendTodoComment(trivia, outerInvocation,
-				"// TODO: review CallInfo usage manually — Mockolate's Do/Returns take typed parameters, not CallInfo");
+			trivia = AppendTodoComment(trivia, anchor,
+				"// TODO(MockolateM002): review CallInfo usage manually — Mockolate's Do/Returns take typed parameters, not CallInfo");
 		}
 
 		return replacement.WithLeadingTrivia(trivia);
@@ -475,7 +477,7 @@ private static InvocationExpressionSyntax BuildSimpleOuter(ExpressionSyntax setu
 	/// </summary>
 	private static SyntaxTriviaList BuildCallInfoTodoTrivia(SyntaxNode anchor) =>
 		AppendTodoComment(anchor.GetLeadingTrivia(), anchor,
-			"// TODO: review CallInfo usage manually — Mockolate's Do/Returns take typed parameters, not CallInfo");
+			"// TODO(MockolateM002): review CallInfo usage manually — Mockolate's Do/Returns take typed parameters, not CallInfo");
 
 	private static SyntaxTriviaList AppendTodoComment(SyntaxTriviaList existingLeading, SyntaxNode anchor,
 		string commentText)
@@ -823,8 +825,14 @@ private static Dictionary<AssignmentExpressionSyntax, InvocationExpressionSyntax
 				raiseMember,
 				eventAccess.Name.WithoutTrivia());
 
-			result[assignment] = SyntaxFactory.InvocationExpression(raiseEventName, raiseArgs)
+			InvocationExpressionSyntax raiseReplacement = SyntaxFactory.InvocationExpression(raiseEventName, raiseArgs)
 				.WithTriviaFrom(assignment);
+			if (eventAccess.Expression is MemberAccessExpressionSyntax nestedEventReceiver)
+			{
+				raiseReplacement = ApplyTodoTrivia(raiseReplacement, assignment, nestedEventReceiver, callInfoTodoNeeded: false);
+			}
+
+			result[assignment] = raiseReplacement;
 		}
 
 		return result;
@@ -973,9 +981,15 @@ private static Dictionary<AssignmentExpressionSyntax, InvocationExpressionSyntax
 			if (assignment.Left is IdentifierNameSyntax { Identifier.Text: "_", } &&
 			    TryExtractReceivedPropertyAccess(assignment.Right, semanticModel, mockSymbol, cancellationToken) is { } got)
 			{
-				result[assignment] = BuildPropertyVerifyChain(got.MockReceiver, got.PropertyName, "Got",
+				InvocationExpressionSyntax gotChain = BuildPropertyVerifyChain(got.MockReceiver, got.PropertyName, "Got",
 						SyntaxFactory.ArgumentList(), got.ReceivedMethod, got.ReceivedArgs)
 					.WithTriviaFrom(assignment);
+				if (got.MockReceiver is MemberAccessExpressionSyntax gotNestedReceiver)
+				{
+					gotChain = ApplyTodoTrivia(gotChain, assignment, gotNestedReceiver, callInfoTodoNeeded: false);
+				}
+
+				result[assignment] = gotChain;
 				continue;
 			}
 
@@ -985,9 +999,15 @@ private static Dictionary<AssignmentExpressionSyntax, InvocationExpressionSyntax
 				ArgumentListSyntax setArgs = BuildPropertyVerifySetArgs(
 					assignment.Right, semanticModel, cancellationToken);
 
-				result[assignment] = BuildPropertyVerifyChain(set.MockReceiver, set.PropertyName, "Set",
+				InvocationExpressionSyntax setChain = BuildPropertyVerifyChain(set.MockReceiver, set.PropertyName, "Set",
 						setArgs, set.ReceivedMethod, set.ReceivedArgs)
 					.WithTriviaFrom(assignment);
+				if (set.MockReceiver is MemberAccessExpressionSyntax setNestedReceiver)
+				{
+					setChain = ApplyTodoTrivia(setChain, assignment, setNestedReceiver, callInfoTodoNeeded: false);
+				}
+
+				result[assignment] = setChain;
 			}
 		}
 
@@ -1130,7 +1150,13 @@ private static Dictionary<InvocationExpressionSyntax, InvocationExpressionSyntax
 			bool isNegative = receivedMethod is "DidNotReceive" or "DidNotReceiveWithAnyArgs";
 			InvocationExpressionSyntax suffix = BuildVerifySuffix(verifyTarget, isNegative, receiverCall.ArgumentList);
 
-			result[outerInvocation] = suffix.WithTriviaFrom(outerInvocation);
+			InvocationExpressionSyntax replacement = suffix.WithTriviaFrom(outerInvocation);
+			if (mockReceiver is MemberAccessExpressionSyntax nestedReceiver)
+			{
+				replacement = ApplyTodoTrivia(replacement, outerInvocation, nestedReceiver, callInfoTodoNeeded: false);
+			}
+
+			result[outerInvocation] = replacement;
 		}
 
 		return result;

Tests/Mockolate.Migration.Tests/MoqCodeFixProviderTests.CallbackTests.cs

@@ -154,5 +154,45 @@ public void Test()
 					}
 				}
 				""");
+
+		[Fact]
+		public async Task WithNestedSetup_PreservesNestedMockTodo()
+			=> await Verifier.VerifyCodeFixAsync(
+				"""
+				using Moq;
+
+				public interface IBar { bool Bar(string x); }
+				public interface IFoo { IBar Child { get; } }
+
+				public class Tests
+				{
+					public void Test()
+					{
+						var mock = [|new Mock<IFoo>()|];
+						mock.Setup(m => m.Child.Bar(It.IsAny<string>()))
+							.Returns(true)
+							.Callback<string>(x => { });
+					}
+				}
+				""",
+				"""
+				using Moq;
+				using Mockolate;
+
+				public interface IBar { bool Bar(string x); }
+				public interface IFoo { IBar Child { get; } }
+
+				public class Tests
+				{
+					public void Test()
+					{
+						var mock = IFoo.CreateMock();
+						// TODO(MockolateM001): register the nested 'mock.Child' chain explicitly in the mock setup (Mockolate doesn't auto-mock recursively)
+						mock.Child.Mock.Bar(It.IsAny<string>())
+							.Returns(true)
+							.Do(x => { });
+					}
+				}
+				""");
 	}
 }

Tests/Mockolate.Migration.Tests/MoqCodeFixProviderTests.NewMockTests.cs

@@ -222,6 +222,7 @@ public class Tests
 					public void Test()
 					{
 						var mock = IFoo.CreateMock();
+						// TODO(MockolateM001): register the nested 'mock.Child.GrandChild' chain explicitly in the mock setup (Mockolate doesn't auto-mock recursively)
 						mock.Child.GrandChild.Mock.Bar(It.IsAny<string>()).Returns(true);
 					}
 				}

Tests/Mockolate.Migration.Tests/MoqCodeFixProviderTests.PropertyTests.cs

@@ -343,6 +343,7 @@ public class Tests
 					public void Test()
 					{
 						var mock = IFoo.CreateMock();
+						// TODO(MockolateM001): register the nested 'mock.Child' chain explicitly in the mock setup (Mockolate doesn't auto-mock recursively)
 						mock.Child.Mock.Verify.Name.Got().Exactly(2);
 					}
 				}

Tests/Mockolate.Migration.Tests/MoqCodeFixProviderTests.SetupTests.cs

@@ -558,6 +558,7 @@ public class Tests
 					public void Test()
 					{
 						var mock = IFoo.CreateMock();
+						// TODO(MockolateM001): register the nested 'mock.Bar.Baz' chain explicitly in the mock setup (Mockolate doesn't auto-mock recursively)
 						mock.Bar.Baz.Mock.Setup.Name.Returns("baz");
 					}
 				}
@@ -593,6 +594,7 @@ public class Tests
 					public void Test()
 					{
 						var mock = IFoo.CreateMock();
+						// TODO(MockolateM001): register the nested 'mock.Bar' chain explicitly in the mock setup (Mockolate doesn't auto-mock recursively)
 						mock.Bar.Mock.Setup.Name.InitializeWith("value");
 					}
 				}
@@ -628,6 +630,7 @@ public class Tests
 					public void Test()
 					{
 						var mock = IFoo.CreateMock();
+						// TODO(MockolateM001): register the nested 'mock.Bar' chain explicitly in the mock setup (Mockolate doesn't auto-mock recursively)
 						mock.Bar.Mock.Setup.Name.Register();
 					}
 				}
@@ -807,6 +810,7 @@ public class Tests
 					public void Test()
 					{
 						var mock = IFoo.CreateMock();
+						// TODO(MockolateM001): register the nested 'mock.Child' chain explicitly in the mock setup (Mockolate doesn't auto-mock recursively)
 						mock.Child.Mock.GetCount()
 							.Returns(1)
 							.Throws<InvalidOperationException>();

Tests/Mockolate.Migration.Tests/MoqCodeFixProviderTests.VerifyEventTests.cs

@@ -111,6 +111,7 @@ public class Tests
 					public void Test()
 					{
 						var mock = IFoo.CreateMock();
+						// TODO(MockolateM001): register the nested 'mock.Child' chain explicitly in the mock setup (Mockolate doesn't auto-mock recursively)
 						mock.Child.Mock.Verify.MyEvent.Subscribed().Never();
 					}
 				}