Merge pull request #6376 from aspnet/rel/2.0.0-preview2

Perform case insensitive lookups for precompiled views

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

@@ -26,6 +26,7 @@ public class RazorViewCompiler : IViewCompiler
     {
         private readonly object _initializeLock = new object();
         private readonly object _cacheLock = new object();
+        private readonly Dictionary<string, Task<CompiledViewDescriptor>> _precompiledViewLookup;
         private readonly ConcurrentDictionary<string, string> _normalizedPathLookup;
         private readonly IFileProvider _fileProvider;
         private readonly RazorTemplateEngine _templateEngine;
@@ -81,12 +82,23 @@ public RazorViewCompiler(
             _normalizedPathLookup = new ConcurrentDictionary<string, string>(StringComparer.Ordinal);
             _cache = new MemoryCache(new MemoryCacheOptions());
 
+            _precompiledViewLookup = new Dictionary<string, Task<CompiledViewDescriptor>>(
+                precompiledViews.Count,
+                StringComparer.OrdinalIgnoreCase);
+
             foreach (var precompiledView in precompiledViews)
             {
-                _cache.Set(
-                    precompiledView.RelativePath,
-                    Task.FromResult(precompiledView),
-                    new MemoryCacheEntryOptions { Priority = CacheItemPriority.NeverRemove });
+                if (_precompiledViewLookup.TryGetValue(precompiledView.RelativePath, out var otherValue))
+                {
+                    var message = string.Join(
+                        Environment.NewLine,
+                        Resources.RazorViewCompiler_ViewPathsDifferOnlyInCase,
+                        otherValue.Result.RelativePath,
+                        precompiledView.RelativePath);
+                    throw new InvalidOperationException(message);
+                }
+
+                _precompiledViewLookup.Add(precompiledView.RelativePath, Task.FromResult(precompiledView));
             }
         }
 
@@ -98,17 +110,40 @@ public Task<CompiledViewDescriptor> CompileAsync(string relativePath)
                 throw new ArgumentNullException(nameof(relativePath));
             }
 
+            // Lookup precompiled views first.
+
             // Attempt to lookup the cache entry using the passed in path. This will succeed if the path is already
             // normalized and a cache entry exists.
-            if (!_cache.TryGetValue(relativePath, out Task<CompiledViewDescriptor> cachedResult))
+            string normalizedPath = null;
+            Task<CompiledViewDescriptor> cachedResult;
+
+            if (_precompiledViewLookup.Count > 0)
             {
-                var normalizedPath = GetNormalizedPath(relativePath);
-                if (!_cache.TryGetValue(normalizedPath, out cachedResult))
+                if (_precompiledViewLookup.TryGetValue(relativePath, out cachedResult))
                 {
-                    cachedResult = CreateCacheEntry(normalizedPath);
+                    return cachedResult;
                 }
+
+                normalizedPath = GetNormalizedPath(relativePath);
+                if (_precompiledViewLookup.TryGetValue(normalizedPath, out cachedResult))
+                {
+                    return cachedResult;
+                }
+            }
+
+            if (_cache.TryGetValue(relativePath, out cachedResult))
+            {
+                return cachedResult;
+            }
+
+            normalizedPath = normalizedPath ?? GetNormalizedPath(relativePath);
+            if (_cache.TryGetValue(normalizedPath, out cachedResult))
+            {
+                return cachedResult;
             }
 
+            // Entry does not exist. Attempt to create one.
+            cachedResult = CreateCacheEntry(normalizedPath);
             return cachedResult;
         }
 

src/Microsoft.AspNetCore.Mvc.Razor/Resources.resx

@@ -191,4 +191,7 @@
   <data name="PropertyMustBeSet" xml:space="preserve">
     <value>The property '{0}' of '{1}' must not be null.</value>
   </data>
+  <data name="RazorViewCompiler_ViewPathsDifferOnlyInCase" xml:space="preserve">
+    <value>The following precompiled view paths differ only in case, which is not supported:</value>
+  </data>
 </root>

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

@@ -16,6 +16,27 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Internal
 {
     public class RazorViewCompilerTest
     {
+        [Fact]
+        public void Constructor_ThrowsIfMultiplePrecompiledViewsHavePathsDifferingOnlyInCase()
+        {
+            // Arrange
+            var fileProvider = new TestFileProvider();
+            var precompiledViews = new[]
+            {
+                new CompiledViewDescriptor { RelativePath = "/Views/Home/About.cshtml" },
+                new CompiledViewDescriptor { RelativePath = "/Views/home/About.cshtml" },
+            };
+            var message = string.Join(
+                Environment.NewLine,
+                "The following precompiled view paths differ only in case, which is not supported:",
+                precompiledViews[0].RelativePath,
+                precompiledViews[1].RelativePath);
+
+            // Act & Assert
+            var ex = Assert.Throws<InvalidOperationException>(() => GetViewCompiler(fileProvider, precompiledViews: precompiledViews));
+            Assert.Equal(message, ex.Message);
+        }
+
         [Fact]
         public async Task CompileAsync_ReturnsResultWithNullAttribute_IfFileIsNotFoundInFileSystem()
         {
@@ -178,6 +199,49 @@ public async Task CompileAsync_ReturnsPrecompiledViews()
             Assert.Same(precompiledView, result);
         }
 
+        [Theory]
+        [InlineData("/views/home/index.cshtml")]
+        [InlineData("/VIEWS/HOME/INDEX.CSHTML")]
+        [InlineData("/viEws/HoME/inDex.cshtml")]
+        public async Task CompileAsync_PerformsCaseInsensitiveLookupsForPrecompiledViews(string lookupPath)
+        {
+            // Arrange
+            var path = "/Views/Home/Index.cshtml";
+            var fileProvider = new TestFileProvider();
+            var fileInfo = fileProvider.AddFile(path, "some content");
+            var precompiledView = new CompiledViewDescriptor
+            {
+                RelativePath = path,
+            };
+            var viewCompiler = GetViewCompiler(fileProvider, precompiledViews: new[] { precompiledView });
+
+            // Act
+            var result = await viewCompiler.CompileAsync(lookupPath);
+
+            // Assert
+            Assert.Same(precompiledView, result);
+        }
+
+        [Fact]
+        public async Task CompileAsync_PerformsCaseInsensitiveLookupsForPrecompiledViews_WithNonNormalizedPaths()
+        {
+            // Arrange
+            var path = "/Views/Home/Index.cshtml";
+            var fileProvider = new TestFileProvider();
+            var fileInfo = fileProvider.AddFile(path, "some content");
+            var precompiledView = new CompiledViewDescriptor
+            {
+                RelativePath = path,
+            };
+            var viewCompiler = GetViewCompiler(fileProvider, precompiledViews: new[] { precompiledView });
+
+            // Act
+            var result = await viewCompiler.CompileAsync("Views\\Home\\Index.cshtml");
+
+            // Assert
+            Assert.Same(precompiledView, result);
+        }
+
         [Fact]
         public async Task CompileAsync_DoesNotRecompile_IfFileTriggerWasSetForPrecompiledView()
         {
@@ -200,7 +264,6 @@ public async Task CompileAsync_DoesNotRecompile_IfFileTriggerWasSetForPrecompile
             Assert.Same(precompiledView, result);
         }
 
-
         [Fact]
         public async Task GetOrAdd_AllowsConcurrentCompilationOfMultipleRazorPages()
         {
@@ -465,7 +528,7 @@ private static TestRazorViewCompiler GetViewCompiler(
             fileProvider = fileProvider ?? new TestFileProvider();
             compilationCallback = compilationCallback ?? (_ => { });
             var options = new TestOptionsManager<RazorViewEngineOptions>();
-            if  (referenceManager == null)
+            if (referenceManager == null)
             {
                 var applicationPartManager = new ApplicationPartManager();
                 var assembly = typeof(RazorViewCompilerTest).Assembly;