Add switch for collecting setup source file info

Up until now, Moq has been collecting source file information for each
setups created. This comes at a slight performance penalty. At this
moment, there is a regression in the .NET Framework which means this
penalty becomes gigantic.

This commit turns source file information collection into an opt-in
feature. Towards that end, a `Switches` property is added to `Mock`
and `MockRepository` which allows users to opt in or out of certain
features. Source file info collection is controlled via the switch
`Switches.CollectDiagnosticFileInfoForSetups`.

Source/AsInterface.cs

@@ -95,6 +95,12 @@ public override TInterface Object
 			get { return this.owner.Object as TInterface; }
 		}
 
+		public override Switches Switches
+		{
+			get => this.owner.Switches;
+			set => this.owner.Switches = value;
+		}
+
 		public override Mock<TNewInterface> As<TNewInterface>()
 		{
 			return this.owner.As<TNewInterface>();

Source/MethodCall.cs

@@ -181,9 +181,14 @@ public Expression SetupExpression
 		[SuppressMessage("Microsoft.Design", "CA1031:DoNotCatchGeneralExceptionTypes")]
 		private void SetFileInfo()
 		{
+#if !NETCORE
+			if ((this.Mock.Switches & Switches.CollectDiagnosticFileInfoForSetups) == 0)
+			{
+				return;
+			}
+
 			try
 			{
-#if !NETCORE
 				var thisMethod = MethodBase.GetCurrentMethod();
 				var mockAssembly = Assembly.GetExecutingAssembly();
 				// Move 'till we're at the entry point into Moq API
@@ -199,12 +204,12 @@ private void SetFileInfo()
 					this.FileName = Path.GetFileName(frame.GetFileName());
 					this.TestMethod = frame.GetMethod();
 				}
-#endif
 			}
 			catch
 			{
 				// Must NEVER fail, as this is a nice-to-have feature only.
 			}
+#endif
 		}
 
 		public void SetOutParameters(ICallContext call)

Source/Mock.cs

@@ -60,12 +60,14 @@ public abstract partial class Mock : IFluentInterface
 		private bool isInitialized;
 		private DefaultValue defaultValue = DefaultValue.Empty;
 		private IDefaultValueProvider defaultValueProvider = new EmptyDefaultValueProvider();
+		private Switches switches;
 
 		/// <include file='Mock.xdoc' path='docs/doc[@for="Mock.ctor"]/*'/>
 		protected Mock()
 		{
 			this.ImplementedInterfaces = new List<Type>();
 			this.InnerMocks = new ConcurrentDictionary<MethodInfo, Mock>();
+			this.switches = Switches.Default;
 		}
 
 		/// <include file='Mock.xdoc' path='docs/doc[@for="Mock.Get"]/*'/>
@@ -228,6 +230,16 @@ internal IDefaultValueProvider DefaultValueProvider
 		/// </summary>
 		internal protected int InternallyImplementedInterfaceCount { get; protected set; }
 
+		/// <summary>
+		/// A set of switches that influence how this mock will operate.
+		/// You can opt in or out of certain features via this property.
+		/// </summary>
+		public virtual Switches Switches
+		{
+			get => this.switches;
+			set => this.switches = value;
+		}
+
 		#region Verify
 
 		/// <include file='Mock.xdoc' path='docs/doc[@for="Mock.Verify"]/*'/>

Source/MockDefaultValueProvider.cs

@@ -71,6 +71,7 @@ public override object ProvideDefault(MethodInfo member)
 					Mock newMock = (Mock)Activator.CreateInstance(mockType, owner.Behavior);
 					newMock.DefaultValue = owner.DefaultValue;
 					newMock.CallBase = owner.CallBase;
+					newMock.Switches = owner.Switches;
 					return newMock;
 				});
 			}

Source/Obsolete/MockFactory.cs

@@ -137,6 +137,7 @@ public partial class MockFactory
 	{
 		List<Mock> mocks = new List<Mock>();
 		MockBehavior defaultBehavior;
+		private Switches switches;
 
 		/// <summary>
 		/// Initializes the factory with the given <paramref name="defaultBehavior"/> 
@@ -148,6 +149,7 @@ public partial class MockFactory
 		public MockFactory(MockBehavior defaultBehavior)
 		{
 			this.defaultBehavior = defaultBehavior;
+			this.switches = Switches.Default;
 		}
 
 		/// <summary>
@@ -168,6 +170,16 @@ public MockFactory(MockBehavior defaultBehavior)
 		/// </summary>
 		protected internal IEnumerable<Mock> Mocks { get { return mocks; } }
 
+		/// <summary>
+		/// A set of switches that influence how mocks created by this factory will operate.
+		/// You can opt in or out of certain features via this property.
+		/// </summary>
+		public Switches Switches
+		{
+			get => this.switches;
+			set => this.switches = value;
+		}
+
 		/// <summary>
 		/// Creates a new mock with the default <see cref="MockBehavior"/> 
 		/// specified at factory construction time.
@@ -292,6 +304,7 @@ protected virtual Mock<T> CreateMock<T>(MockBehavior behavior, object[] args)
 
 			mock.CallBase = this.CallBase;
 			mock.DefaultValue = this.DefaultValue;
+			mock.Switches = this.switches;
 
 			return mock;
 		}

Source/Switches.cs

@@ -0,0 +1,63 @@
+//Copyright (c) 2007. Clarius Consulting, Manas Technology Solutions, InSTEDD
+//https://github.com/moq/moq4
+//All rights reserved.
+
+//Redistribution and use in source and binary forms, 
+//with or without modification, are permitted provided 
+//that the following conditions are met:
+
+//    * Redistributions of source code must retain the 
+//    above copyright notice, this list of conditions and 
+//    the following disclaimer.
+
+//    * Redistributions in binary form must reproduce 
+//    the above copyright notice, this list of conditions 
+//    and the following disclaimer in the documentation 
+//    and/or other materials provided with the distribution.
+
+//    * Neither the name of Clarius Consulting, Manas Technology Solutions or InSTEDD nor the 
+//    names of its contributors may be used to endorse 
+//    or promote products derived from this software 
+//    without specific prior written permission.
+
+//THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 
+//CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 
+//INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
+//MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
+//DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR 
+//CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
+//SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
+//BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
+//SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
+//INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
+//WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 
+//NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
+//OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
+//SUCH DAMAGE.
+
+//[This is the BSD license, see
+// http://www.opensource.org/licenses/bsd-license.php]
+
+using System;
+
+namespace Moq
+{
+	/// <summary>
+	/// Represents a switch, or a combination of switches, that can be either enabled or disabled.
+	/// When set via <see cref="Mock.Switches"/> or <see cref="MockFactory.Switches"/>, they determine how a mock will operate.
+	/// </summary>
+	[Flags]
+	public enum Switches
+	{
+		/// <summary>
+		/// The default set of switches. The switches covered by this enumeration value may change between different versions of Moq.
+		/// </summary>
+		Default = 0,
+
+		/// <summary>
+		/// When enabled, specifies that source file information should be collected for each setup.
+		/// This results in more helpful error messages, but may affect performance.
+		/// </summary>
+		CollectDiagnosticFileInfoForSetups = 1 << 0,
+	}
+}

UnitTests/MockDefaultValueProviderFixture.cs

@@ -102,6 +102,17 @@ public void DefaultValueIsNotChangedWhenPerformingInternalInvocation()
 			Assert.Equal(DefaultValue.Empty, mockBar.DefaultValue);
 		}
 
+		[Fact]
+		public void Inner_mocks_inherit_switches_of_parent_mock()
+		{
+			const Switches expectedSwitches = Switches.CollectDiagnosticFileInfoForSetups;
+
+			var parentMock = new Mock<IFoo>() { DefaultValue = DefaultValue.Mock, Switches = expectedSwitches };
+			var innerMock = Mock.Get(parentMock.Object.Bar);
+
+			Assert.Equal(expectedSwitches, actual: innerMock.Switches);
+		}
+
 		public interface IFoo
 		{
 			IBar Bar { get; set; }

UnitTests/MockFixture.cs

@@ -922,6 +922,14 @@ private static Foo MakeFoo(IMock<IBar> barMock)
 			return new Foo(barMock.Object);
 		}
 
+		[Fact]
+		public void Mock_initially_uses_default_switches()
+		{
+			var mock = new Mock<IFoo>();
+
+			Assert.Equal(Switches.Default, actual: mock.Switches);
+		}
+
 		public class Foo
 		{
 			public Foo() : this(new Bar()) { }

UnitTests/MockRepositoryFixture.cs

@@ -146,6 +146,25 @@ public void ShouldCreateMocksWithFactoryCallBase()
 			Assert.True(mock.Object.BaseCalled);
 		}
 
+		[Fact]
+		public void Repository_initially_uses_default_switches()
+		{
+			var repository = new MockRepository(MockBehavior.Default);
+
+			Assert.Equal(Switches.Default, actual: repository.Switches);
+		}
+
+		[Fact]
+		public void Mock_inherits_switches_from_repository()
+		{
+			const Switches expectedSwitches = Switches.CollectDiagnosticFileInfoForSetups;
+
+			var repository = new MockRepository(MockBehavior.Default) { Switches = expectedSwitches };
+			var mock = repository.Create<IFoo>();
+
+			Assert.Equal(expectedSwitches, actual: mock.Switches);
+		}
+
 		public interface IFoo
 		{
 			void Do();

UnitTests/VerifyFixture.cs

@@ -981,6 +981,36 @@ public void DoesNotThrowCollectionModifiedWhenMoreInvocationsInterceptedDuringVe
 			});
 		}
 
+#if !NETCORE
+		[Fact]
+		public void Enabling_diagnostic_file_info_leads_to_that_information_in_verification_error_messages()
+		{
+			var repository = new MockRepository(MockBehavior.Default);
+			repository.Switches |= Switches.CollectDiagnosticFileInfoForSetups;
+
+			var mock = repository.Create<IFoo>();
+			mock.Setup(m => m.Submit());
+
+			var ex = Assert.Throws<MockException>(() => repository.VerifyAll());
+			Assert.Contains("in ", ex.Message);
+			Assert.Contains("VerifyFixture.cs: line ", ex.Message);
+		}
+#endif
+
+		[Fact]
+		public void Disabling_diagnostic_file_info_leads_to_that_information_missing_in_verification_error_messages()
+		{
+			var repository = new MockRepository(MockBehavior.Default);
+			repository.Switches &= ~Switches.CollectDiagnosticFileInfoForSetups;
+
+			var mock = repository.Create<IFoo>();
+			mock.Setup(m => m.Submit());
+
+			var ex = Assert.Throws<MockException>(() => repository.VerifyAll());
+			Assert.DoesNotContain("in ", ex.Message);
+			Assert.DoesNotContain("VerifyFixture.cs: line ", ex.Message);
+		}
+
 		public interface IBar
 		{
 			int? Value { get; set; }