Improve `SearchLocations` handling

- do not blindly use `FindPage()` / `FindView()` result in `Exception.Message` or returned results
  - failure scenarios involve new `Any()` calls but rarely additional `List<string>()` allocations
- change `ViewEngine_ViewNotFound` resource to be consistent with similar errors
  - remove trailing period at end of searched locations list

nit: remove remaining `null` checks of `SearchedLocations` in not found cases; never `null` then

src/Microsoft.AspNet.Mvc.Razor/RazorView.cs

@@ -245,6 +245,7 @@ namespace Microsoft.AspNet.Mvc.Razor
         private IRazorPage GetLayoutPage(ViewContext context, string executingFilePath, string layoutPath)
         {
             var layoutPageResult = _viewEngine.GetPage(executingFilePath, layoutPath, isPartial: true);
+            var originalLocations = layoutPageResult.SearchedLocations;
             if (layoutPageResult.Page == null)
             {
                 layoutPageResult = _viewEngine.FindPage(context, layoutPath, isPartial: true);
@@ -252,8 +253,18 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             if (layoutPageResult.Page == null)
             {
-                var locations =
+                var locations = string.Empty;
-                    Environment.NewLine + string.Join(Environment.NewLine, layoutPageResult.SearchedLocations);
+                if (originalLocations.Any())
+                {
+                    locations = Environment.NewLine + string.Join(Environment.NewLine, originalLocations);
+                }
+
+                if (layoutPageResult.SearchedLocations.Any())
+                {
+                    locations +=
+                        Environment.NewLine + string.Join(Environment.NewLine, layoutPageResult.SearchedLocations);
+                }
+
                 throw new InvalidOperationException(Resources.FormatLayoutCannotBeLocated(layoutPath, locations));
             }
 

src/Microsoft.AspNet.Mvc.ViewFeatures/PartialViewResult.cs

@@ -62,7 +62,7 @@ namespace Microsoft.AspNet.Mvc
             var executor = services.GetRequiredService<PartialViewResultExecutor>();
 
             var result = executor.FindView(context, this);
-            result.EnsureSuccessful();
+            result.EnsureSuccessful(originalLocations: null);
 
             var view = result.View;
             using (view as IDisposable)

src/Microsoft.AspNet.Mvc.ViewFeatures/Properties/Resources.Designer.cs

@@ -507,7 +507,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
         }
 
         /// <summary>
-        /// The view '{0}' was not found. The following locations were searched:{1}.
+        /// The view '{0}' was not found. The following locations were searched:{1}
         /// </summary>
         internal static string ViewEngine_ViewNotFound
         {
@@ -515,7 +515,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
         }
 
         /// <summary>
-        /// The view '{0}' was not found. The following locations were searched:{1}.
+        /// The view '{0}' was not found. The following locations were searched:{1}
         /// </summary>
         internal static string FormatViewEngine_ViewNotFound(object p0, object p1)
         {

src/Microsoft.AspNet.Mvc.ViewFeatures/Resources.resx

@@ -212,7 +212,7 @@
     <value>The partial view '{0}' was not found. The following locations were searched:{1}</value>
   </data>
   <data name="ViewEngine_ViewNotFound" xml:space="preserve">
-    <value>The view '{0}' was not found. The following locations were searched:{1}.</value>
+    <value>The view '{0}' was not found. The following locations were searched:{1}</value>
   </data>
   <data name="HtmlHelper_TextAreaParameterOutOfRange" xml:space="preserve">
     <value>The value must be greater than or equal to zero.</value>

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewComponents/ViewViewComponentResult.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Collections.Generic;
 using System.Diagnostics;
 using System.Globalization;
 using System.Threading.Tasks;
@@ -82,10 +83,12 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
             var isNullOrEmptyViewName = string.IsNullOrEmpty(ViewName);
 
             ViewEngineResult result = null;
+            IEnumerable<string> originalLocations = null;
             if (!isNullOrEmptyViewName)
             {
                 // If view name was passed in is already a path, the view engine will handle this.
                 result = viewEngine.GetView(viewContext.ExecutingFilePath, ViewName, isPartial: true);
+                originalLocations = result.SearchedLocations;
             }
 
             if (result == null || !result.Success)
@@ -111,7 +114,7 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
                 result = viewEngine.FindView(viewContext, qualifiedViewName, isPartial: true);
             }
 
-            var view = result.EnsureSuccessful().View;
+            var view = result.EnsureSuccessful(originalLocations).View;
             using (view as IDisposable)
             {
                 if (_diagnosticSource == null)
@@ -121,7 +124,11 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
 
                 _diagnosticSource.ViewComponentBeforeViewExecute(context, view);
 
-                var childViewContext = new ViewContext(viewContext, view, ViewData ?? context.ViewData, context.Writer);
+                var childViewContext = new ViewContext(
+                    viewContext,
+                    view,
+                    ViewData ?? context.ViewData,
+                    context.Writer);
                 await view.RenderAsync(childViewContext);
 
                 _diagnosticSource.ViewComponentAfterViewExecute(context, view);

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewEngines/ViewEngineResult.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using Microsoft.AspNet.Mvc.ViewFeatures;
 
 namespace Microsoft.AspNet.Mvc.ViewEngines
@@ -64,14 +65,30 @@ namespace Microsoft.AspNet.Mvc.ViewEngines
             };
         }
 
-        public ViewEngineResult EnsureSuccessful()
+        /// <summary>
+        /// Ensure this <see cref="ViewEngineResult"/> was successful.
+        /// </summary>
+        /// <param name="originalLocations">
+        /// Additional <see cref="SearchedLocations"/> to include in the thrown <see cref="InvalidOperationException"/>
+        /// if <see cref="Success"/> is <c>false</c>.
+        /// </param>
+        /// <exception cref="InvalidOperationException">
+        /// Thrown if <see cref="Success"/> is <c>false</c>.
+        /// </exception>
+        /// <returns>This <see cref="ViewEngineResult"/> if <see cref="Success"/> is <c>true</c>.</returns>
+        public ViewEngineResult EnsureSuccessful(IEnumerable<string> originalLocations)
         {
             if (!Success)
             {
                 var locations = string.Empty;
-                if (SearchedLocations != null)
+                if (originalLocations != null && originalLocations.Any())
                 {
-                    locations = Environment.NewLine + string.Join(Environment.NewLine, SearchedLocations);
+                    locations = Environment.NewLine + string.Join(Environment.NewLine, originalLocations);
+                }
+
+                if (SearchedLocations.Any())
+                {
+                    locations += Environment.NewLine + string.Join(Environment.NewLine, SearchedLocations);
                 }
 
                 throw new InvalidOperationException(Resources.FormatViewEngine_ViewNotFound(ViewName, locations));

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewFeatures/HtmlHelper.cs

@@ -544,6 +544,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
                 ViewContext.ExecutingFilePath,
                 partialViewName,
                 isPartial: true);
+            var originalLocations = viewEngineResult.SearchedLocations;
             if (!viewEngineResult.Success)
             {
                 viewEngineResult = _viewEngine.FindView(ViewContext, partialViewName, isPartial: true);
@@ -552,10 +553,15 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
             if (!viewEngineResult.Success)
             {
                 var locations = string.Empty;
-                if (viewEngineResult.SearchedLocations != null)
+                if (originalLocations.Any())
                 {
-                    locations = Environment.NewLine +
+                    locations = Environment.NewLine + string.Join(Environment.NewLine, originalLocations);
-                        string.Join(Environment.NewLine, viewEngineResult.SearchedLocations);
+                }
+
+                if (viewEngineResult.SearchedLocations.Any())
+                {
+                    locations +=
+                        Environment.NewLine + string.Join(Environment.NewLine, viewEngineResult.SearchedLocations);
                 }
 
                 throw new InvalidOperationException(

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewFeatures/PartialViewResultExecutor.cs

@@ -2,7 +2,9 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Collections.Generic;
 using System.Diagnostics;
+using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Mvc.Diagnostics;
 using Microsoft.AspNet.Mvc.Infrastructure;
@@ -70,11 +72,31 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
             var viewName = viewResult.ViewName ?? actionContext.ActionDescriptor.Name;
 
             var result = viewEngine.GetView(executingFilePath: null, viewPath: viewName, isPartial: true);
+            var originalResult = result;
             if (!result.Success)
             {
                 result = viewEngine.FindView(actionContext, viewName, isPartial: true);
             }
 
+            if (!result.Success)
+            {
+                if (originalResult.SearchedLocations.Any())
+                {
+                    if (result.SearchedLocations.Any())
+                    {
+                        // Return a new ViewEngineResult listing all searched locations.
+                        var locations = new List<string>(originalResult.SearchedLocations);
+                        locations.AddRange(result.SearchedLocations);
+                        result = ViewEngineResult.NotFound(viewName, locations);
+                    }
+                    else
+                    {
+                        // GetView() searched locations but FindView() did not. Use first ViewEngineResult.
+                        result = originalResult;
+                    }
+                }
+            }
+
             if (result.Success)
             {
                 DiagnosticSource.ViewFound(actionContext, true, viewResult, viewName, result.View);

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewFeatures/ViewResultExecutor.cs

@@ -2,12 +2,13 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Collections.Generic;
 using System.Diagnostics;
+using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Mvc.Infrastructure;
 using Microsoft.AspNet.Mvc.Logging;
 using Microsoft.AspNet.Mvc.ViewEngines;
-using Microsoft.AspNet.Mvc.ViewFeatures.Logging;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.OptionsModel;
 
@@ -69,11 +70,31 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
             var viewName = viewResult.ViewName ?? actionContext.ActionDescriptor.Name;
 
             var result = viewEngine.GetView(executingFilePath: null, viewPath: viewName, isPartial: false);
+            var originalResult = result;
             if (!result.Success)
             {
                 result = viewEngine.FindView(actionContext, viewName, isPartial: false);
             }
 
+            if (!result.Success)
+            {
+                if (originalResult.SearchedLocations.Any())
+                {
+                    if (result.SearchedLocations.Any())
+                    {
+                        // Return a new ViewEngineResult listing all searched locations.
+                        var locations = new List<string>(originalResult.SearchedLocations);
+                        locations.AddRange(result.SearchedLocations);
+                        result = ViewEngineResult.NotFound(viewName, locations);
+                    }
+                    else
+                    {
+                        // GetView() searched locations but FindView() did not. Use first ViewEngineResult.
+                        result = originalResult;
+                    }
+                }
+            }
+
             if (result.Success)
             {
                 if (DiagnosticSource.IsEnabled("Microsoft.AspNet.Mvc.ViewFound"))

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewResult.cs

@@ -62,7 +62,7 @@ namespace Microsoft.AspNet.Mvc
             var executor = services.GetRequiredService<ViewResultExecutor>();
 
             var result = executor.FindView(context, this);
-            result.EnsureSuccessful();
+            result.EnsureSuccessful(originalLocations: null);
 
             var view = result.View;
             using (view as IDisposable)

test/Microsoft.AspNet.Mvc.Razor.Test/RazorViewTest.cs

@@ -368,7 +368,50 @@ namespace Microsoft.AspNet.Mvc.Razor
         }
 
         [Fact]
-        public async Task RenderAsync_ThrowsIfLayoutPageCannotBeFound()
+        public async Task RenderAsync_ThrowsIfLayoutPageCannotBeFound_MessageUsesGetPageLocations()
+        {
+            // Arrange
+            var expected = string.Join(
+                Environment.NewLine,
+                "The layout view 'Does-Not-Exist-Layout' could not be located. The following locations were searched:",
+                "path1",
+                "path2");
+
+            var layoutPath = "Does-Not-Exist-Layout";
+            var page = new TestableRazorPage(v =>
+            {
+                v.Layout = layoutPath;
+            });
+
+            var viewEngine = new Mock<IRazorViewEngine>(MockBehavior.Strict);
+            var activator = new Mock<IRazorPageActivator>();
+            var view = new RazorView(
+                viewEngine.Object,
+                Mock.Of<IRazorPageActivator>(),
+                new IRazorPage[0],
+                page,
+                new HtmlTestEncoder(),
+                isPartial: false);
+            var viewContext = CreateViewContext(view);
+            viewEngine
+                .Setup(v => v.GetPage(/*executingFilePath*/ null, layoutPath, /*isPartial*/ true))
+                .Returns(new RazorPageResult(layoutPath, new[] { "path1", "path2" }))
+                .Verifiable();
+            viewEngine
+                .Setup(v => v.FindPage(viewContext, layoutPath, /*isPartial*/ true))
+                .Returns(new RazorPageResult(layoutPath, Enumerable.Empty<string>()))
+                .Verifiable();
+
+            // Act
+            var ex = await Assert.ThrowsAsync<InvalidOperationException>(() => view.RenderAsync(viewContext));
+
+            // Assert
+            Assert.Equal(expected, ex.Message);
+            viewEngine.Verify();
+        }
+
+        [Fact]
+        public async Task RenderAsync_ThrowsIfLayoutPageCannotBeFound_MessageUsesFindPageLocations()
         {
             // Arrange
             var expected = string.Join(
@@ -410,6 +453,51 @@ namespace Microsoft.AspNet.Mvc.Razor
             viewEngine.Verify();
         }
 
+        [Fact]
+        public async Task RenderAsync_ThrowsIfLayoutPageCannotBeFound_MessageUsesAllLocations()
+        {
+            // Arrange
+            var expected = string.Join(
+                Environment.NewLine,
+                "The layout view 'Does-Not-Exist-Layout' could not be located. The following locations were searched:",
+                "path1",
+                "path2",
+                "path3",
+                "path4");
+
+            var layoutPath = "Does-Not-Exist-Layout";
+            var page = new TestableRazorPage(v =>
+            {
+                v.Layout = layoutPath;
+            });
+
+            var viewEngine = new Mock<IRazorViewEngine>(MockBehavior.Strict);
+            var activator = new Mock<IRazorPageActivator>();
+            var view = new RazorView(
+                viewEngine.Object,
+                Mock.Of<IRazorPageActivator>(),
+                new IRazorPage[0],
+                page,
+                new HtmlTestEncoder(),
+                isPartial: false);
+            var viewContext = CreateViewContext(view);
+            viewEngine
+                .Setup(v => v.GetPage(/*executingFilePath*/ null, layoutPath, /*isPartial*/ true))
+                .Returns(new RazorPageResult(layoutPath, new[] { "path1", "path2" }))
+                .Verifiable();
+            viewEngine
+                .Setup(v => v.FindPage(viewContext, layoutPath, /*isPartial*/ true))
+                .Returns(new RazorPageResult(layoutPath, new[] { "path3", "path4" }))
+                .Verifiable();
+
+            // Act
+            var ex = await Assert.ThrowsAsync<InvalidOperationException>(() => view.RenderAsync(viewContext));
+
+            // Assert
+            Assert.Equal(expected, ex.Message);
+            viewEngine.Verify();
+        }
+
         [Fact]
         public async Task RenderAsync_ExecutesLayoutPages()
         {

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/PartialViewResultTest.cs

@@ -26,14 +26,51 @@ namespace Microsoft.AspNet.Mvc
     public class PartialViewResultTest
     {
         [Fact]
-        public async Task ExecuteResultAsync_Throws_IfViewCouldNotBeFound()
+        public async Task ExecuteResultAsync_Throws_IfViewCouldNotBeFound_MessageUsesGetViewLocations()
         {
             // Arrange
             var expected = string.Join(
                 Environment.NewLine,
                 "The view 'MyView' was not found. The following locations were searched:",
                 "Location1",
-                "Location2.");
+                "Location2");
+
+            var actionContext = GetActionContext();
+
+            var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
+            viewEngine
+                .Setup(v => v.GetView(/*executingFilePath*/ null, "MyView", /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("MyView", new[] { "Location1", "Location2" }))
+                .Verifiable();
+            viewEngine
+                .Setup(v => v.FindView(It.IsAny<ActionContext>(), "MyView", /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("MyView", Enumerable.Empty<string>()))
+                .Verifiable();
+
+            var viewResult = new PartialViewResult
+            {
+                ViewEngine = viewEngine.Object,
+                ViewName = "MyView",
+                ViewData = new ViewDataDictionary(new EmptyModelMetadataProvider()),
+                TempData = Mock.Of<ITempDataDictionary>(),
+            };
+
+            // Act and Assert
+            var ex = await Assert.ThrowsAsync<InvalidOperationException>(
+                () => viewResult.ExecuteResultAsync(actionContext));
+            Assert.Equal(expected, ex.Message);
+            viewEngine.Verify();
+        }
+
+        [Fact]
+        public async Task ExecuteResultAsync_Throws_IfViewCouldNotBeFound_MessageUsesFindViewLocations()
+        {
+            // Arrange
+            var expected = string.Join(
+                Environment.NewLine,
+                "The view 'MyView' was not found. The following locations were searched:",
+                "Location1",
+                "Location2");
 
             var actionContext = GetActionContext();
 
@@ -62,6 +99,45 @@ namespace Microsoft.AspNet.Mvc
             viewEngine.Verify();
         }
 
+        [Fact]
+        public async Task ExecuteResultAsync_Throws_IfViewCouldNotBeFound_MessageUsesAllLocations()
+        {
+            // Arrange
+            var expected = string.Join(
+                Environment.NewLine,
+                "The view 'MyView' was not found. The following locations were searched:",
+                "Location1",
+                "Location2",
+                "Location3",
+                "Location4");
+
+            var actionContext = GetActionContext();
+
+            var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
+            viewEngine
+                .Setup(v => v.GetView(/*executingFilePath*/ null, "MyView", /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("MyView", new[] { "Location1", "Location2" }))
+                .Verifiable();
+            viewEngine
+                .Setup(v => v.FindView(It.IsAny<ActionContext>(), "MyView", /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("MyView", new[] { "Location3", "Location4" }))
+                .Verifiable();
+
+            var viewResult = new PartialViewResult
+            {
+                ViewEngine = viewEngine.Object,
+                ViewName = "MyView",
+                ViewData = new ViewDataDictionary(new EmptyModelMetadataProvider()),
+                TempData = Mock.Of<ITempDataDictionary>(),
+            };
+
+            // Act and Assert
+            var ex = await Assert.ThrowsAsync<InvalidOperationException>(
+                () => viewResult.ExecuteResultAsync(actionContext));
+            Assert.Equal(expected, ex.Message);
+            viewEngine.Verify();
+        }
+
         [Fact]
         public async Task ExecuteResultAsync_FindsAndExecutesView()
         {

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/Rendering/HtmlHelperPartialExtensionsTest.cs

@@ -3,10 +3,12 @@
 
 #if MOCK_SUPPORT
 using System;
+using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Html.Abstractions;
 using Microsoft.AspNet.Mvc.ModelBinding;
 using Microsoft.AspNet.Mvc.TestCommon;
+using Microsoft.AspNet.Mvc.ViewEngines;
 using Microsoft.AspNet.Mvc.ViewFeatures;
 using Moq;
 using Xunit;
@@ -188,6 +190,184 @@ namespace Microsoft.AspNet.Mvc.Rendering
             Assert.Equal(expected, HtmlContentUtilities.HtmlContentToString(actual));
         }
 
+        [Fact]
+        public async Task PartialAsync_Throws_IfViewNotFound_MessageUsesGetViewLocations()
+        {
+            // Arrange
+            var expected = "The partial view 'test-view' was not found. The following locations were searched:" +
+                Environment.NewLine +
+                "location1" + Environment.NewLine +
+                "location2";
+
+            var model = new TestModel();
+            var viewEngine = new Mock<ICompositeViewEngine>(MockBehavior.Strict);
+            viewEngine
+                .Setup(v => v.GetView(/*executingFilePath*/ null, It.IsAny<string>(), /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("test-view", new[] { "location1", "location2" }))
+                .Verifiable();
+            viewEngine
+                .Setup(v => v.FindView(It.IsAny<ActionContext>(), It.IsAny<string>(), /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("test-view", Enumerable.Empty<string>()))
+                .Verifiable();
+
+            var helper = DefaultTemplatesUtilities.GetHtmlHelper(model, viewEngine.Object);
+            var viewData = helper.ViewData;
+
+            // Act & Assert
+            var exception = await Assert.ThrowsAsync<InvalidOperationException>(
+                () => helper.PartialAsync("test-view", model, viewData));
+            Assert.Equal(expected, exception.Message);
+        }
+
+        [Fact]
+        public async Task PartialAsync_Throws_IfViewNotFound_MessageUsesFindViewLocations()
+        {
+            // Arrange
+            var expected = "The partial view 'test-view' was not found. The following locations were searched:" +
+                Environment.NewLine +
+                "location1" + Environment.NewLine +
+                "location2";
+
+            var model = new TestModel();
+            var viewEngine = new Mock<ICompositeViewEngine>(MockBehavior.Strict);
+            viewEngine
+                .Setup(v => v.GetView(/*executingFilePath*/ null, It.IsAny<string>(), /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("test-view", Enumerable.Empty<string>()))
+                .Verifiable();
+            viewEngine
+                .Setup(v => v.FindView(It.IsAny<ActionContext>(), It.IsAny<string>(), /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("test-view", new[] { "location1", "location2" }))
+                .Verifiable();
+
+            var helper = DefaultTemplatesUtilities.GetHtmlHelper(model, viewEngine.Object);
+            var viewData = helper.ViewData;
+
+            // Act & Assert
+            var exception = await Assert.ThrowsAsync<InvalidOperationException>(
+                () => helper.PartialAsync("test-view", model, viewData));
+            Assert.Equal(expected, exception.Message);
+        }
+
+        [Fact]
+        public async Task PartialAsync_Throws_IfViewNotFound_MessageUsesAllLocations()
+        {
+            // Arrange
+            var expected = "The partial view 'test-view' was not found. The following locations were searched:" +
+                Environment.NewLine +
+                "location1" + Environment.NewLine +
+                "location2" + Environment.NewLine +
+                "location3" + Environment.NewLine +
+                "location4";
+
+            var model = new TestModel();
+            var viewEngine = new Mock<ICompositeViewEngine>(MockBehavior.Strict);
+            viewEngine
+                .Setup(v => v.GetView(/*executingFilePath*/ null, It.IsAny<string>(), /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("test-view", new[] { "location1", "location2" }))
+                .Verifiable();
+            viewEngine
+                .Setup(v => v.FindView(It.IsAny<ActionContext>(), It.IsAny<string>(), /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("test-view", new[] { "location3", "location4" }))
+                .Verifiable();
+
+            var helper = DefaultTemplatesUtilities.GetHtmlHelper(model, viewEngine.Object);
+            var viewData = helper.ViewData;
+
+            // Act & Assert
+            var exception = await Assert.ThrowsAsync<InvalidOperationException>(
+                () => helper.PartialAsync("test-view", model, viewData));
+            Assert.Equal(expected, exception.Message);
+        }
+
+        [Fact]
+        public async Task RenderPartialAsync_Throws_IfViewNotFound_MessageUsesGetViewLocations()
+        {
+            // Arrange
+            var expected = "The partial view 'test-view' was not found. The following locations were searched:" +
+                Environment.NewLine +
+                "location1" + Environment.NewLine +
+                "location2";
+
+            var model = new TestModel();
+            var viewEngine = new Mock<ICompositeViewEngine>(MockBehavior.Strict);
+            viewEngine
+                .Setup(v => v.GetView(/*executingFilePath*/ null, It.IsAny<string>(), /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("test-view", new[] { "location1", "location2" }))
+                .Verifiable();
+            viewEngine
+                .Setup(v => v.FindView(It.IsAny<ActionContext>(), It.IsAny<string>(), /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("test-view", Enumerable.Empty<string>()))
+                .Verifiable();
+
+            var helper = DefaultTemplatesUtilities.GetHtmlHelper(model, viewEngine.Object);
+            var viewData = helper.ViewData;
+
+            // Act & Assert
+            var exception = await Assert.ThrowsAsync<InvalidOperationException>(
+                () => helper.RenderPartialAsync("test-view", model, viewData));
+            Assert.Equal(expected, exception.Message);
+        }
+
+        [Fact]
+        public async Task RenderPartialAsync_Throws_IfViewNotFound_MessageUsesFindViewLocations()
+        {
+            // Arrange
+            var expected = "The partial view 'test-view' was not found. The following locations were searched:" +
+                Environment.NewLine +
+                "location1" + Environment.NewLine +
+                "location2";
+
+            var model = new TestModel();
+            var viewEngine = new Mock<ICompositeViewEngine>(MockBehavior.Strict);
+            viewEngine
+                .Setup(v => v.GetView(/*executingFilePath*/ null, It.IsAny<string>(), /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("test-view", Enumerable.Empty<string>()))
+                .Verifiable();
+            viewEngine
+                .Setup(v => v.FindView(It.IsAny<ActionContext>(), It.IsAny<string>(), /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("test-view", new[] { "location1", "location2" }))
+                .Verifiable();
+
+            var helper = DefaultTemplatesUtilities.GetHtmlHelper(model, viewEngine.Object);
+            var viewData = helper.ViewData;
+
+            // Act & Assert
+            var exception = await Assert.ThrowsAsync<InvalidOperationException>(
+                () => helper.RenderPartialAsync("test-view", model, viewData));
+            Assert.Equal(expected, exception.Message);
+        }
+
+        [Fact]
+        public async Task RenderPartialAsync_Throws_IfViewNotFound_MessageUsesAllLocations()
+        {
+            // Arrange
+            var expected = "The partial view 'test-view' was not found. The following locations were searched:" +
+                Environment.NewLine +
+                "location1" + Environment.NewLine +
+                "location2" + Environment.NewLine +
+                "location3" + Environment.NewLine +
+                "location4";
+
+            var model = new TestModel();
+            var viewEngine = new Mock<ICompositeViewEngine>(MockBehavior.Strict);
+            viewEngine
+                .Setup(v => v.GetView(/*executingFilePath*/ null, It.IsAny<string>(), /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("test-view", new[] { "location1", "location2" }))
+                .Verifiable();
+            viewEngine
+                .Setup(v => v.FindView(It.IsAny<ActionContext>(), It.IsAny<string>(), /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("test-view", new[] { "location3", "location4" }))
+                .Verifiable();
+
+            var helper = DefaultTemplatesUtilities.GetHtmlHelper(model, viewEngine.Object);
+            var viewData = helper.ViewData;
+
+            // Act & Assert
+            var exception = await Assert.ThrowsAsync<InvalidOperationException>(
+                () => helper.RenderPartialAsync("test-view", model, viewData));
+            Assert.Equal(expected, exception.Message);
+        }
+
         private sealed class TestModel
         {
             public override string ToString()

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/ViewComponents/ViewViewComponentResultTest.cs

@@ -143,13 +143,51 @@ namespace Microsoft.AspNet.Mvc
         }
 
         [Fact]
-        public void Execute_ThrowsIfPartialViewCannotBeFound()
+        public void Execute_ThrowsIfPartialViewCannotBeFound_MessageUsesGetViewLocations()
         {
             // Arrange
             var expected = string.Join(Environment.NewLine,
                         "The view 'Components/Invoke/some-view' was not found. The following locations were searched:",
                         "location1",
-                        "location2.");
+                        "location2");
+
+            var view = Mock.Of<IView>();
+
+            var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
+            viewEngine
+                .Setup(v => v.GetView(/*executingFilePath*/ null, "some-view", /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("some-view", new[] { "location1", "location2" }))
+                .Verifiable();
+            viewEngine
+                .Setup(v => v.FindView(It.IsAny<ActionContext>(), "Components/Invoke/some-view", /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("Components/Invoke/some-view", Enumerable.Empty<string>()))
+                .Verifiable();
+
+            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());
+
+            var result = new ViewViewComponentResult
+            {
+                ViewEngine = viewEngine.Object,
+                ViewName = "some-view",
+                ViewData = viewData,
+                TempData = _tempDataDictionary,
+            };
+
+            var viewComponentContext = GetViewComponentContext(view, viewData);
+
+            // Act and Assert
+            var ex = Assert.Throws<InvalidOperationException>(() => result.Execute(viewComponentContext));
+            Assert.Equal(expected, ex.Message);
+        }
+
+        [Fact]
+        public void Execute_ThrowsIfPartialViewCannotBeFound_MessageUsesFindViewLocations()
+        {
+            // Arrange
+            var expected = string.Join(Environment.NewLine,
+                        "The view 'Components/Invoke/some-view' was not found. The following locations were searched:",
+                        "location1",
+                        "location2");
 
             var view = Mock.Of<IView>();
 
@@ -180,6 +218,46 @@ namespace Microsoft.AspNet.Mvc
             Assert.Equal(expected, ex.Message);
         }
 
+        [Fact]
+        public void Execute_ThrowsIfPartialViewCannotBeFound_MessageUsesAllLocations()
+        {
+            // Arrange
+            var expected = string.Join(Environment.NewLine,
+                        "The view 'Components/Invoke/some-view' was not found. The following locations were searched:",
+                        "location1",
+                        "location2",
+                        "location3",
+                        "location4");
+
+            var view = Mock.Of<IView>();
+
+            var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
+            viewEngine
+                .Setup(v => v.GetView(/*executingFilePath*/ null, "some-view", /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("some-view", new[] { "location1", "location2" }))
+                .Verifiable();
+            viewEngine
+                .Setup(v => v.FindView(It.IsAny<ActionContext>(), "Components/Invoke/some-view", /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("Components/Invoke/some-view", new[] { "location3", "location4" }))
+                .Verifiable();
+
+            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());
+
+            var result = new ViewViewComponentResult
+            {
+                ViewEngine = viewEngine.Object,
+                ViewName = "some-view",
+                ViewData = viewData,
+                TempData = _tempDataDictionary,
+            };
+
+            var viewComponentContext = GetViewComponentContext(view, viewData);
+
+            // Act and Assert
+            var ex = Assert.Throws<InvalidOperationException>(() => result.Execute(viewComponentContext));
+            Assert.Equal(expected, ex.Message);
+        }
+
         [Fact]
         public void Execute_DoesNotWrapThrownExceptionsInAggregateExceptions()
         {
@@ -305,20 +383,22 @@ namespace Microsoft.AspNet.Mvc
             var expected = string.Join(Environment.NewLine,
                 "The view 'Components/Invoke/some-view' was not found. The following locations were searched:",
                 "view-location1",
-                "view-location2.");
+                "view-location2",
+                "view-location3",
+                "view-location4");
 
             var view = Mock.Of<IView>();
 
             var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
             viewEngine
                 .Setup(v => v.GetView(/*executingFilePath*/ null, "some-view", /*isPartial*/ true))
-                .Returns(ViewEngineResult.NotFound("some-view", Enumerable.Empty<string>()))
+                .Returns(ViewEngineResult.NotFound("some-view", new[] { "view-location1", "view-location2" }))
                 .Verifiable();
             viewEngine
                 .Setup(v => v.FindView(It.IsAny<ActionContext>(), "Components/Invoke/some-view", /*isPartial*/ true))
                 .Returns(ViewEngineResult.NotFound(
                     "Components/Invoke/some-view",
-                    new[] { "view-location1", "view-location2" }))
+                    new[] { "view-location3", "view-location4" }))
                 .Verifiable();
 
             var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());
@@ -423,7 +503,10 @@ namespace Microsoft.AspNet.Mvc
             viewEngine.Verify();
         }
 
-        private static ViewComponentContext GetViewComponentContext(IView view, ViewDataDictionary viewData, object diagnosticListener = null)
+        private static ViewComponentContext GetViewComponentContext(
+            IView view,
+            ViewDataDictionary viewData,
+            object diagnosticListener = null)
         {
             var diagnosticSource = new DiagnosticListener("Microsoft.AspNet");
             if (diagnosticListener == null)

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/ViewFeatures/PartialViewResultExecutorTest.cs

@@ -76,6 +76,111 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
             Assert.Equal(viewName, viewEngineResult.ViewName);
         }
 
+        [Fact]
+        public void FindView_ReturnsExpectedNotFoundResult_WithGetViewLocations()
+        {
+            // Arrange
+            var expectedLocations = new[] { "location1", "location2" };
+            var context = GetActionContext();
+            var executor = GetViewExecutor();
+
+            var viewName = "myview";
+            var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
+            viewEngine
+                .Setup(e => e.GetView(/*executingFilePath*/ null, "myview", /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("myview", expectedLocations))
+                .Verifiable();
+            viewEngine
+                .Setup(e => e.FindView(context, "myview", /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("myview", Enumerable.Empty<string>()));
+
+            var viewResult = new PartialViewResult
+            {
+                ViewName = viewName,
+                ViewEngine = viewEngine.Object,
+                ViewData = new ViewDataDictionary(new EmptyModelMetadataProvider()),
+                TempData = Mock.Of<ITempDataDictionary>(),
+            };
+
+            // Act
+            var result = executor.FindView(context, viewResult);
+
+            // Assert
+            Assert.False(result.Success);
+            Assert.Null(result.View);
+            Assert.Equal(expectedLocations, result.SearchedLocations);
+        }
+
+        [Fact]
+        public void FindView_ReturnsExpectedNotFoundResult_WithFindViewLocations()
+        {
+            // Arrange
+            var expectedLocations = new[] { "location1", "location2" };
+            var context = GetActionContext();
+            var executor = GetViewExecutor();
+
+            var viewName = "myview";
+            var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
+            viewEngine
+                .Setup(e => e.GetView(/*executingFilePath*/ null, "myview", /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("myview", Enumerable.Empty<string>()))
+                .Verifiable();
+            viewEngine
+                .Setup(e => e.FindView(context, "myview", /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("myview", expectedLocations));
+
+            var viewResult = new PartialViewResult
+            {
+                ViewName = viewName,
+                ViewEngine = viewEngine.Object,
+                ViewData = new ViewDataDictionary(new EmptyModelMetadataProvider()),
+                TempData = Mock.Of<ITempDataDictionary>(),
+            };
+
+            // Act
+            var result = executor.FindView(context, viewResult);
+
+            // Assert
+            Assert.False(result.Success);
+            Assert.Null(result.View);
+            Assert.Equal(expectedLocations, result.SearchedLocations);
+        }
+
+        [Fact]
+        public void FindView_ReturnsExpectedNotFoundResult_WithAllLocations()
+        {
+            // Arrange
+            var expectedLocations = new[] { "location1", "location2", "location3", "location4" };
+            var context = GetActionContext();
+            var executor = GetViewExecutor();
+
+            var viewName = "myview";
+            var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
+            viewEngine
+                .Setup(e => e.GetView(/*executingFilePath*/ null, "myview", /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("myview", new[] { "location1", "location2" }))
+                .Verifiable();
+            viewEngine
+                .Setup(e => e.FindView(context, "myview", /*isPartial*/ true))
+                .Returns(ViewEngineResult.NotFound("myview", new[] { "location3", "location4" }));
+
+            var viewResult = new PartialViewResult
+            {
+                ViewName = viewName,
+                ViewEngine = viewEngine.Object,
+                ViewData = new ViewDataDictionary(new EmptyModelMetadataProvider()),
+                TempData = Mock.Of<ITempDataDictionary>(),
+            };
+
+            // Act
+            var result = executor.FindView(context, viewResult);
+
+            // Assert
+            Assert.False(result.Success);
+            Assert.Null(result.View);
+            Assert.Equal(expectedLocations, result.SearchedLocations);
+        }
+
         [Fact]
         public void FindView_WritesDiagnostic_ViewFound()
         {

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/ViewFeatures/ViewResultExecutorTest.cs

@@ -76,6 +76,108 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
             Assert.Equal(viewName, viewEngineResult.ViewName);
         }
 
+        [Fact]
+        public void FindView_ReturnsExpectedNotFoundResult_WithGetViewLocations()
+        {
+            // Arrange
+            var expectedLocations = new[] { "location1", "location2" };
+            var context = GetActionContext();
+            var executor = GetViewExecutor();
+
+            var viewName = "myview";
+            var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
+            viewEngine
+                .Setup(e => e.GetView(/*executingFilePath*/ null, "myview", /*isPartial*/ false))
+                .Returns(ViewEngineResult.NotFound("myview", expectedLocations));
+            viewEngine
+                .Setup(e => e.FindView(context, "myview", /*isPartial*/ false))
+                .Returns(ViewEngineResult.NotFound("myview", Enumerable.Empty<string>()));
+
+            var viewResult = new ViewResult
+            {
+                ViewName = viewName,
+                ViewEngine = viewEngine.Object,
+                ViewData = new ViewDataDictionary(new EmptyModelMetadataProvider()),
+                TempData = Mock.Of<ITempDataDictionary>(),
+            };
+
+            // Act
+            var result = executor.FindView(context, viewResult);
+
+            // Assert
+            Assert.False(result.Success);
+            Assert.Null(result.View);
+            Assert.Equal(expectedLocations, result.SearchedLocations);
+        }
+
+        [Fact]
+        public void FindView_ReturnsExpectedNotFoundResult_WithFindViewLocations()
+        {
+            // Arrange
+            var expectedLocations = new[] { "location1", "location2" };
+            var context = GetActionContext();
+            var executor = GetViewExecutor();
+
+            var viewName = "myview";
+            var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
+            viewEngine
+                .Setup(e => e.GetView(/*executingFilePath*/ null, "myview", /*isPartial*/ false))
+                .Returns(ViewEngineResult.NotFound("myview", Enumerable.Empty<string>()));
+            viewEngine
+                .Setup(e => e.FindView(context, "myview", /*isPartial*/ false))
+                .Returns(ViewEngineResult.NotFound("myview", expectedLocations));
+
+            var viewResult = new ViewResult
+            {
+                ViewName = viewName,
+                ViewEngine = viewEngine.Object,
+                ViewData = new ViewDataDictionary(new EmptyModelMetadataProvider()),
+                TempData = Mock.Of<ITempDataDictionary>(),
+            };
+
+            // Act
+            var result = executor.FindView(context, viewResult);
+
+            // Assert
+            Assert.False(result.Success);
+            Assert.Null(result.View);
+            Assert.Equal(expectedLocations, result.SearchedLocations);
+        }
+
+        [Fact]
+        public void FindView_ReturnsExpectedNotFoundResult_WithAllLocations()
+        {
+            // Arrange
+            var expectedLocations = new[] { "location1", "location2", "location3", "location4" };
+            var context = GetActionContext();
+            var executor = GetViewExecutor();
+
+            var viewName = "myview";
+            var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
+            viewEngine
+                .Setup(e => e.GetView(/*executingFilePath*/ null, "myview", /*isPartial*/ false))
+                .Returns(ViewEngineResult.NotFound("myview", new[] { "location1", "location2" }));
+            viewEngine
+                .Setup(e => e.FindView(context, "myview", /*isPartial*/ false))
+                .Returns(ViewEngineResult.NotFound("myview", new[] { "location3", "location4" }));
+
+            var viewResult = new ViewResult
+            {
+                ViewName = viewName,
+                ViewEngine = viewEngine.Object,
+                ViewData = new ViewDataDictionary(new EmptyModelMetadataProvider()),
+                TempData = Mock.Of<ITempDataDictionary>(),
+            };
+
+            // Act
+            var result = executor.FindView(context, viewResult);
+
+            // Assert
+            Assert.False(result.Success);
+            Assert.Null(result.View);
+            Assert.Equal(expectedLocations, result.SearchedLocations);
+        }
+
         [Fact]
         public void FindView_WritesDiagnostic_ViewFound()
         {

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/ViewResultTest.cs

@@ -26,14 +26,51 @@ namespace Microsoft.AspNet.Mvc
     public class ViewResultTest
     {
         [Fact]
-        public async Task ExecuteResultAsync_Throws_IfViewCouldNotBeFound()
+        public async Task ExecuteResultAsync_Throws_IfViewCouldNotBeFound_MessageUsesGetViewLocations()
         {
             // Arrange
             var expected = string.Join(
                 Environment.NewLine,
                 "The view 'MyView' was not found. The following locations were searched:",
                 "Location1",
-                "Location2.");
+                "Location2");
+
+            var actionContext = GetActionContext();
+
+            var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
+            viewEngine
+                .Setup(e => e.GetView(/*executingFilePath*/ null, "MyView", /*isPartial*/ false))
+                .Returns(ViewEngineResult.NotFound("MyView", new[] { "Location1", "Location2" }))
+                .Verifiable();
+            viewEngine
+                .Setup(v => v.FindView(It.IsAny<ActionContext>(), It.IsAny<string>(), /*isPartial*/ false))
+                .Returns(ViewEngineResult.NotFound("MyView", Enumerable.Empty<string>()))
+                .Verifiable();
+
+            var viewResult = new ViewResult
+            {
+                ViewEngine = viewEngine.Object,
+                ViewName = "MyView",
+                ViewData = new ViewDataDictionary(new EmptyModelMetadataProvider()),
+                TempData = Mock.Of<ITempDataDictionary>(),
+            };
+
+            // Act and Assert
+            var ex = await Assert.ThrowsAsync<InvalidOperationException>(
+                () => viewResult.ExecuteResultAsync(actionContext));
+            Assert.Equal(expected, ex.Message);
+            viewEngine.Verify();
+        }
+
+        [Fact]
+        public async Task ExecuteResultAsync_Throws_IfViewCouldNotBeFound_MessageUsesFindViewLocations()
+        {
+            // Arrange
+            var expected = string.Join(
+                Environment.NewLine,
+                "The view 'MyView' was not found. The following locations were searched:",
+                "Location1",
+                "Location2");
 
             var actionContext = GetActionContext();
 
@@ -62,6 +99,45 @@ namespace Microsoft.AspNet.Mvc
             viewEngine.Verify();
         }
 
+        [Fact]
+        public async Task ExecuteResultAsync_Throws_IfViewCouldNotBeFound_MessageUsesAllLocations()
+        {
+            // Arrange
+            var expected = string.Join(
+                Environment.NewLine,
+                "The view 'MyView' was not found. The following locations were searched:",
+                "Location1",
+                "Location2",
+                "Location3",
+                "Location4");
+
+            var actionContext = GetActionContext();
+
+            var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
+            viewEngine
+                .Setup(e => e.GetView(/*executingFilePath*/ null, "MyView", /*isPartial*/ false))
+                .Returns(ViewEngineResult.NotFound("MyView", new[] { "Location1", "Location2" }))
+                .Verifiable();
+            viewEngine
+                .Setup(v => v.FindView(It.IsAny<ActionContext>(), It.IsAny<string>(), /*isPartial*/ false))
+                .Returns(ViewEngineResult.NotFound("MyView", new[] { "Location3", "Location4" }))
+                .Verifiable();
+
+            var viewResult = new ViewResult
+            {
+                ViewEngine = viewEngine.Object,
+                ViewName = "MyView",
+                ViewData = new ViewDataDictionary(new EmptyModelMetadataProvider()),
+                TempData = Mock.Of<ITempDataDictionary>(),
+            };
+
+            // Act and Assert
+            var ex = await Assert.ThrowsAsync<InvalidOperationException>(
+                () => viewResult.ExecuteResultAsync(actionContext));
+            Assert.Equal(expected, ex.Message);
+            viewEngine.Verify();
+        }
+
         [Fact]
         public async Task ExecuteResultAsync_FindsAndExecutesView()
         {