Make SetupProperty work with recursive expressions again

CHANGELOG.md

@@ -5,6 +5,13 @@ All notable changes to this project will be documented in this file.
 The format is loosely based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 
 
+## Unreleased
+
+#### Fixed
+
+* Regression: Property stubs not working on sub mock (@aaronburro, #1240)
+
+
 ## 4.17.1 (2022-02-26)
 
 #### Added

src/Moq/Mock.cs

@@ -609,6 +609,30 @@ internal static SequenceSetup SetupSequence(Mock mock, LambdaExpression expressi
 			});
 		}
 
+		internal static StubbedPropertySetup SetupProperty(Mock mock, LambdaExpression expression, object initialValue)
+		{
+			Guard.NotNull(expression, nameof(expression));
+
+			var pi = expression.ToPropertyInfo();
+
+			if (!pi.CanRead(out var getter))
+			{
+				Guard.CanRead(pi);
+			}
+
+			if (!pi.CanWrite(out var setter))
+			{
+				Guard.CanWrite(pi);
+			}
+
+			return Mock.SetupRecursive(mock, expression, (targetMock, _, _) =>
+			{
+				var setup = new StubbedPropertySetup(targetMock, expression, getter, setter, initialValue);
+				targetMock.MutableSetups.Add(setup);
+				return setup;
+			});
+		}
+
 		private static TSetup SetupRecursive<TSetup>(Mock mock, LambdaExpression expression, Func<Mock, Expression, MethodExpectation, TSetup> setupLast, bool allowNonOverridableLastProperty = false)
 			where TSetup : ISetup
 		{

src/Moq/Mock`1.cs

@@ -628,22 +628,7 @@ public Mock<T> SetupProperty<TProperty>(Expression<Func<T, TProperty>> property)
 		/// </example>
 		public Mock<T> SetupProperty<TProperty>(Expression<Func<T, TProperty>> property, TProperty initialValue)
 		{
-			Guard.NotNull(property, nameof(property));
-
-			var pi = property.ToPropertyInfo();
-
-			if (!pi.CanRead(out var getter))
-			{
-				Guard.CanRead(pi);
-			}
-
-			if (!pi.CanWrite(out var setter))
-			{
-				Guard.CanWrite(pi);
-			}
-
-			var setup = new StubbedPropertySetup(this, property, getter, setter, initialValue);
-			this.MutableSetups.Add(setup);
+			Mock.SetupProperty(this, property, initialValue);
 			return this;
 		}
 

tests/Moq.Tests/Regressions/IssueReportsFixture.cs

@@ -3740,6 +3740,48 @@ public void Pass_byte_array_indirectly_via_method_call()
 
 		#endregion
 
+		#region 1240
+
+		public class Issue1240
+		{
+			public interface IFoo { IBar Bar { get; } }
+			public interface IBar
+			{
+				string Prop1 { get; }
+				string Prop2 { get; set; }
+			}
+
+			[Fact]
+			public void Property_on_submock_should_be_stubbed_1()
+			{
+				const string prop2 = "Prop2";
+				var mock = new Mock<IFoo>();
+
+				// mock.SetupGet(m => m.Bar.Prop1).Returns("Prop1");
+				//  ^ This line being commented out is the only difference from the test below.
+				//    Its absence would cause a `NullReferenceException` later.
+
+				mock.SetupProperty(m => m.Bar.Prop2);
+				mock.Object.Bar.Prop2 = prop2;
+				Assert.Equal(prop2, mock.Object.Bar.Prop2);
+			}
+
+			[Fact]
+			public void Property_on_submock_should_be_stubbed_2()
+			{
+				const string prop2 = "Prop2";
+				var mock = new Mock<IFoo>();
+
+				mock.SetupGet(m => m.Bar.Prop1).Returns("Prop1");
+
+				mock.SetupProperty(m => m.Bar.Prop2);
+				mock.Object.Bar.Prop2 = prop2;
+				Assert.Equal(prop2, mock.Object.Bar.Prop2);
+			}
+		}
+
+		#endregion
+
 		// Old @ Google Code
 
 		#region #47