From a9d73017cd09aaceb30bca268a2f5197a4afe60f Mon Sep 17 00:00:00 2001
From: stakx <stakx@eml.cc>
Date: Sun, 2 Jun 2019 19:25:35 +0200
Subject: [PATCH] Implement strict behavior for LINQ to Mocks

---
 src/Moq/Linq/Mock.cs              |  5 ++++-
 src/Moq/Linq/MockRepository.cs    |  5 ++++-
 src/Moq/Linq/MockSetupsBuilder.cs |  8 +++++---
 src/Moq/Linq/Mocks.cs             | 30 ++++++++++++++++++++++++++++--
 4 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/src/Moq/Linq/Mock.cs b/src/Moq/Linq/Mock.cs
index e440cb404..c0bec848f 100644
--- a/src/Moq/Linq/Mock.cs
+++ b/src/Moq/Linq/Mock.cs
@@ -38,7 +38,10 @@ public static T Of<T>(MockBehavior behavior) where T : class
 			// which involved a lot of avoidable `IQueryable` query provider overhead and lambda compilation.
 			// What it really boils down to is this (much faster) code:
 			var mock = new Mock<T>(behavior);
-			mock.SetupAllProperties();
+			if (behavior != MockBehavior.Strict)
+			{
+				mock.SetupAllProperties();
+			}
 			return mock.Object;
 		}
 
diff --git a/src/Moq/Linq/MockRepository.cs b/src/Moq/Linq/MockRepository.cs
index d98e5e58f..d714c64d2 100644
--- a/src/Moq/Linq/MockRepository.cs
+++ b/src/Moq/Linq/MockRepository.cs
@@ -141,7 +141,10 @@ private IEnumerable<T> CreateMocks<T>(MockBehavior behavior) where T : class
 			do
 			{
 				var mock = this.Create<T>(behavior);
-				mock.SetupAllProperties();
+				if (behavior != MockBehavior.Strict)
+				{
+					mock.SetupAllProperties();
+				}
 
 				yield return mock.Object;
 			}
diff --git a/src/Moq/Linq/MockSetupsBuilder.cs b/src/Moq/Linq/MockSetupsBuilder.cs
index b139bdb13..ef4f0f0d8 100644
--- a/src/Moq/Linq/MockSetupsBuilder.cs
+++ b/src/Moq/Linq/MockSetupsBuilder.cs
@@ -217,9 +217,11 @@ private static Expression ConvertToSetupProperty(Expression targetObject, Expres
 			var mockExpression = propertyCall.Object;
 			var propertyExpression = propertyCall.Arguments.First().StripQuotes();
 
-			// Because Mocks.CreateMocks (the underlying implementation of the IQueryable provider
-			// already sets up all properties as stubs, we can safely just set the value here, 
-			// which also allows the use of this querying capability against plain DTO even 
+			// We can safely just set the value here since `SetProperty` will temporarily enable auto-stubbing
+			// if the underlying `IQueryable` provider implementation hasn't already enabled it permanently by
+			// calling `SetupAllProperties`.
+			//
+			// This method also enables the use of this querying capability against plain DTO even
 			// if their properties are not virtual.
 			var setPropertyMethod = typeof(Mocks)
 				.GetMethod("SetProperty", BindingFlags.Static | BindingFlags.NonPublic)
diff --git a/src/Moq/Linq/Mocks.cs b/src/Moq/Linq/Mocks.cs
index 986dd8745..1be5e5d49 100644
--- a/src/Moq/Linq/Mocks.cs
+++ b/src/Moq/Linq/Mocks.cs
@@ -118,7 +118,10 @@ private static IEnumerable<T> CreateMocks<T>(MockBehavior behavior) where T : cl
 			do
 			{
 				var mock = new Mock<T>(behavior);
-				mock.SetupAllProperties();
+				if (behavior != MockBehavior.Strict)
+				{
+					mock.SetupAllProperties();
+				}
 
 				yield return mock.Object;
 			}
@@ -135,7 +138,30 @@ internal static bool SetProperty<T, TResult>(Mock<T> target, Expression<Func<T,
 			var memberExpr = (MemberExpression)propertyReference.Body;
 			var member = (PropertyInfo)memberExpr.Member;
 
-			member.SetValue(target.Object, value, null);
+			// For strict mocks, we haven't called `SetupAllProperties` on the mock being set up.
+			// Therefore, whenever a property is being initialized, we quickly need to enable auto-stubbing.
+			//
+			// (One would think that it would be simpler to perform `SetupAllProperties` at the beginning
+			// and leave it enabled until the initialized mock is returned to the user. However, transforming
+			// the LINQ query such that a final disable of auto-stubbing happens is much more difficult!)
+
+			var temporaryAutoSetupProperties = target.AutoSetupPropertiesDefaultValueProvider == null;
+
+			if (temporaryAutoSetupProperties)
+			{
+				target.AutoSetupPropertiesDefaultValueProvider = target.DefaultValueProvider;
+			}
+			try
+			{
+				member.SetValue(target.Object, value, null);
+			}
+			finally
+			{
+				if (temporaryAutoSetupProperties)
+				{
+					target.AutoSetupPropertiesDefaultValueProvider = null;
+				}
+			}
 
 			return true;
 		}