Normalize paths returned by view location expanders

Fixes #6448

src/Microsoft.AspNetCore.Mvc.Razor/Compilation/CompiledViewDescriptor.cs

@@ -1,6 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // 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 Microsoft.Extensions.Primitives;
 

src/Microsoft.AspNetCore.Mvc.Razor/Internal/DefaultRazorPageFactoryProvider.cs

@@ -57,11 +57,11 @@ public RazorPageFactoryResult CreateFactory(string relativePath)
                 var pageFactory = Expression
                     .Lambda<Func<IRazorPage>>(objectInitializeExpression)
                     .Compile();
-                return new RazorPageFactoryResult(pageFactory, viewDescriptor.ExpirationTokens, viewDescriptor.IsPrecompiled);
+                return new RazorPageFactoryResult(viewDescriptor, pageFactory);
             }
             else
             {
-                return new RazorPageFactoryResult(viewDescriptor.ExpirationTokens);
+                return new RazorPageFactoryResult(viewDescriptor, razorPageFactory: null);
             }
         }
     }

src/Microsoft.AspNetCore.Mvc.Razor/RazorPageFactoryResult.cs

@@ -2,8 +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 Microsoft.Extensions.Primitives;
+using Microsoft.AspNetCore.Mvc.Razor.Compilation;
 
 namespace Microsoft.AspNetCore.Mvc.Razor
 {
@@ -12,61 +11,18 @@ namespace Microsoft.AspNetCore.Mvc.Razor
     /// </summary>
     public struct RazorPageFactoryResult
     {
-        /// <summary>
-        /// Initializes a new instance of <see cref="RazorPageFactoryResult"/> with the
-        /// specified <paramref name="expirationTokens"/>.
-        /// </summary>
-        /// <param name="expirationTokens">One or more <see cref="IChangeToken"/> instances.</param>
-        public RazorPageFactoryResult(IList<IChangeToken> expirationTokens)
-        {
-            if (expirationTokens == null)
-            {
-                throw new ArgumentNullException(nameof(expirationTokens));
-            }
-
-            ExpirationTokens = expirationTokens;
-            RazorPageFactory = null;
-            IsPrecompiled = false;
-        }
-
         /// <summary>
         /// Initializes a new instance of <see cref="RazorPageFactoryResult"/> with the
         /// specified <see cref="IRazorPage"/> factory.
         /// </summary>
         /// <param name="razorPageFactory">The <see cref="IRazorPage"/> factory.</param>
-        /// <param name="expirationTokens">One or more <see cref="IChangeToken"/> instances.</param>
+        /// <param name="viewDescriptor">The <see cref="CompiledViewDescriptor"/>.</param>
         public RazorPageFactoryResult(
-            Func<IRazorPage> razorPageFactory,
-            IList<IChangeToken> expirationTokens)
-            : this(razorPageFactory, expirationTokens, isPrecompiled: false)
+            CompiledViewDescriptor viewDescriptor,
+            Func<IRazorPage> razorPageFactory)
         {
-        }
-
-        /// <summary>
-        /// Initializes a new instance of <see cref="RazorPageFactoryResult"/> with the
-        /// specified <see cref="IRazorPage"/> factory.
-        /// </summary>
-        /// <param name="razorPageFactory">The <see cref="IRazorPage"/> factory.</param>
-        /// <param name="expirationTokens">One or more <see cref="IChangeToken"/> instances.</param>
-        /// <param name="isPrecompiled"><c>true</c> if the view is precompiled, <c>false</c> otherwise.</param>
-        public RazorPageFactoryResult(
-            Func<IRazorPage> razorPageFactory,
-            IList<IChangeToken> expirationTokens,
-            bool isPrecompiled)
-        {
-            if (razorPageFactory == null)
-            {
-                throw new ArgumentNullException(nameof(razorPageFactory));
-            }
-
-            if (expirationTokens == null)
-            {
-                throw new ArgumentNullException(nameof(expirationTokens));
-            }
-
+            ViewDescriptor = viewDescriptor ?? throw new ArgumentNullException(nameof(viewDescriptor));
             RazorPageFactory = razorPageFactory;
-            ExpirationTokens = expirationTokens;
-            IsPrecompiled = isPrecompiled;
         }
 
         /// <summary>
@@ -76,19 +32,13 @@ public RazorPageFactoryResult(
         public Func<IRazorPage> RazorPageFactory { get; }
 
         /// <summary>
-        /// One or more <see cref="IChangeToken"/>s associated with this instance of
-        /// <see cref="RazorPageFactoryResult"/>.
+        /// Gets the <see cref="CompiledViewDescriptor"/>.
         /// </summary>
-        public IList<IChangeToken> ExpirationTokens { get; }
+        public CompiledViewDescriptor ViewDescriptor { get; }
 
         /// <summary>
         /// Gets a value that determines if the page was successfully located.
         /// </summary>
         public bool Success => RazorPageFactory != null;
-
-        /// <summary>
-        /// Gets a value that determines if the view is precompiled.
-        /// </summary>
-        public bool IsPrecompiled { get; }
     }
 }

src/Microsoft.AspNetCore.Mvc.Razor/RazorViewEngine.cs

@@ -393,21 +393,22 @@ internal ViewLocationCacheResult CreateCacheResult(
             bool isMainPage)
         {
             var factoryResult = _pageFactory.CreateFactory(relativePath);
-            if (factoryResult.ExpirationTokens != null)
+            var viewDescriptor = factoryResult.ViewDescriptor;
+            if (viewDescriptor?.ExpirationTokens != null)
             {
-                for (var i = 0; i < factoryResult.ExpirationTokens.Count; i++)
+                for (var i = 0; i < viewDescriptor.ExpirationTokens.Count; i++)
                 {
-                    expirationTokens.Add(factoryResult.ExpirationTokens[i]);
+                    expirationTokens.Add(viewDescriptor.ExpirationTokens[i]);
                 }
             }
 
             if (factoryResult.Success)
             {
                 // Only need to lookup _ViewStarts for the main page.
                 var viewStartPages = isMainPage ?
-                    GetViewStartPages(relativePath, expirationTokens) :
+                    GetViewStartPages(viewDescriptor.RelativePath, expirationTokens) :
                     Array.Empty<ViewLocationCacheItem>();
-                if (factoryResult.IsPrecompiled)
+                if (viewDescriptor.IsPrecompiled)
                 {
                     _logger.PrecompiledViewFound(relativePath);
                 }
@@ -424,17 +425,23 @@ private IReadOnlyList<ViewLocationCacheItem> GetViewStartPages(
             string path,
             HashSet<IChangeToken> expirationTokens)
         {
-            var applicationRelativePath = MakePathApplicationRelative(path);
+            if (IsApplicationRelativePath(path))
+            {
+                path = path.Substring(1);
+            }
+
+            var relativePath = ViewPath.NormalizePath(path);
             var viewStartPages = new List<ViewLocationCacheItem>();
 
-            foreach (var viewStartProjectItem in _razorProject.FindHierarchicalItems(applicationRelativePath, ViewStartFileName))
+            foreach (var viewStartProjectItem in _razorProject.FindHierarchicalItems(relativePath, ViewStartFileName))
             {
                 var result = _pageFactory.CreateFactory(viewStartProjectItem.Path);
-                if (result.ExpirationTokens != null)
+                var viewDescriptor = result.ViewDescriptor;
+                if (viewDescriptor?.ExpirationTokens != null)
                 {
-                    for (var i = 0; i < result.ExpirationTokens.Count; i++)
+                    for (var i = 0; i < viewDescriptor.ExpirationTokens.Count; i++)
                     {
-                        expirationTokens.Add(result.ExpirationTokens[i]);
+                        expirationTokens.Add(viewDescriptor.ExpirationTokens[i]);
                     }
                 }
 
@@ -476,22 +483,6 @@ private static bool IsApplicationRelativePath(string name)
             return name[0] == '~' || name[0] == '/';
         }
 
-        private string MakePathApplicationRelative(string path)
-        {
-            Debug.Assert(!string.IsNullOrEmpty(path));
-            if (path[0] == '~')
-            {
-                path = path.Substring(1);
-            }
-
-            if (path[0] != '/')
-            {
-                path = '/' + path;
-            }
-
-            return path;
-        }
-
         private static bool IsRelativePath(string name)
         {
             Debug.Assert(!string.IsNullOrEmpty(name));

test/Microsoft.AspNetCore.Mvc.FunctionalTests/ViewEngineTests.cs

@@ -476,5 +476,21 @@ public async Task RazorView_SetsViewPathAndExecutingPagePath()
                 ignoreLineEndingDifferences: true);
 #endif
         }
+
+        [Fact]
+        public async Task ViewEngine_NormalizesPathsReturnedByViewLocationExpanders()
+        {
+            // Arrange
+            var expected = 
+@"Layout
+Page
+Partial";
+
+            // Act
+            var responseContent = await Client.GetStringAsync("/BackSlash");
+
+            // Assert
+            Assert.Equal(expected, responseContent.Trim());
+        }
     }
 }

test/Microsoft.AspNetCore.Mvc.Razor.Test/Internal/DefaultRazorPageFactoryProviderTest.cs

@@ -13,7 +13,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Internal
     public class DefaultRazorPageFactoryProviderTest
     {
         [Fact]
-        public void CreateFactory_ReturnsExpirationTokensFromCompilerCache_ForUnsuccessfulResults()
+        public void CreateFactory_ReturnsViewDescriptor_ForUnsuccessfulResults()
         {
             // Arrange
             var path = "/file-does-not-exist";
@@ -39,11 +39,11 @@ public void CreateFactory_ReturnsExpirationTokensFromCompilerCache_ForUnsuccessf
 
             // Assert
             Assert.False(result.Success);
-            Assert.Equal(expirationTokens, result.ExpirationTokens);
+            Assert.Same(descriptor, result.ViewDescriptor);
         }
 
         [Fact]
-        public void CreateFactory_ReturnsExpirationTokensFromCompilerCache_ForSuccessfulResults()
+        public void CreateFactory_ReturnsViewDescriptor_ForSuccessfulResults()
         {
             // Arrange
             var relativePath = "/file-exists";