Remove IViewsProvider and make view lookup to the feature provider

src/Microsoft.AspNetCore.Mvc.Core/ApplicationParts/AssemblyPart.cs

@@ -15,24 +15,8 @@ namespace Microsoft.AspNetCore.Mvc.ApplicationParts
     public class AssemblyPart :
         ApplicationPart,
         IApplicationPartTypeProvider,
-        ICompilationReferencesProvider,
-        IViewsProvider
+        ICompilationReferencesProvider
     {
-        /// <summary>
-        /// Gets the suffix for the view assembly.
-        /// </summary>
-        public static readonly string PrecompiledViewsAssemblySuffix = ".PrecompiledViews";
-
-        /// <summary>
-        /// Gets the namespace for the <see cref="ViewInfoContainer"/> type in the view assembly.
-        /// </summary>
-        public static readonly string ViewInfoContainerNamespace = "AspNetCore";
-
-        /// <summary>
-        /// Gets the type name for the view collection type in the view assembly.
-        /// </summary>
-        public static readonly string ViewInfoContainerTypeName = "__PrecompiledViewCollection";
-
         /// <summary>
         /// Initalizes a new <see cref="AssemblyPart"/> instance.
         /// </summary>
@@ -60,27 +44,6 @@ public AssemblyPart(Assembly assembly)
         /// <inheritdoc />
         public IEnumerable<TypeInfo> Types => Assembly.DefinedTypes;
 
-        /// <inheritdoc />
-        public IEnumerable<ViewInfo> Views
-        {
-            get
-            {
-                var precompiledAssemblyName = new AssemblyName(Assembly.FullName);
-                precompiledAssemblyName.Name = precompiledAssemblyName.Name + PrecompiledViewsAssemblySuffix;
-
-                var typeName = $"{ViewInfoContainerNamespace}.{ViewInfoContainerTypeName},{precompiledAssemblyName}";
-                var viewInfoContainerTypeName = Type.GetType(typeName);
-
-                if (viewInfoContainerTypeName == null)
-                {
-                    return null;
-                }
-
-                var precompiledViews = (ViewInfoContainer)Activator.CreateInstance(viewInfoContainerTypeName);
-                return precompiledViews.ViewInfos;
-            }
-        }
-
         /// <inheritdoc />
         public IEnumerable<string> GetReferencePaths()
         {

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

@@ -1,8 +1,10 @@
 // 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 System.Linq;
+using System.Reflection;
 using Microsoft.AspNetCore.Mvc.ApplicationParts;
 
 namespace Microsoft.AspNetCore.Mvc.Razor.Compilation
@@ -12,20 +14,53 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Compilation
     /// </summary>
     public class ViewsFeatureProvider : IApplicationFeatureProvider<ViewsFeature>
     {
+        /// <summary>
+        /// Gets the suffix for the view assembly.
+        /// </summary>
+        public static readonly string PrecompiledViewsAssemblySuffix = ".PrecompiledViews";
+
+        /// <summary>
+        /// Gets the namespace for the <see cref="ViewInfoContainer"/> type in the view assembly.
+        /// </summary>
+        public static readonly string ViewInfoContainerNamespace = "AspNetCore";
+
+        /// <summary>
+        /// Gets the type name for the view collection type in the view assembly.
+        /// </summary>
+        public static readonly string ViewInfoContainerTypeName = "__PrecompiledViewCollection";
+
         /// <inheritdoc />
         public void PopulateFeature(IEnumerable<ApplicationPart> parts, ViewsFeature feature)
         {
-            foreach (var provider in parts.OfType<IViewsProvider>())
+            foreach (var assemblyPart in parts.OfType<AssemblyPart>())
             {
-                var precompiledViews = provider.Views;
-                if (precompiledViews != null)
+                var viewInfoContainerTypeName = GetViewInfoContainerType(assemblyPart);
+                if (viewInfoContainerTypeName == null)
                 {
-                    foreach (var viewInfo in precompiledViews)
-                    {
-                        feature.Views[viewInfo.Path] = viewInfo.Type;
-                    }
+                    continue;
+                }
+
+                var viewContainer = (ViewInfoContainer)Activator.CreateInstance(viewInfoContainerTypeName);
+
+                foreach (var item in viewContainer.ViewInfos)
+                {
+                    feature.Views[item.Path] = item.Type;
                 }
             }
         }
+
+        /// <summary>
+        /// Gets the type of <see cref="ViewInfoContainer"/> for the specified <paramref name="assemblyPart"/>.
+        /// </summary>
+        /// <param name="assemblyPart">The <see cref="AssemblyPart"/>.</param>
+        /// <returns>The <see cref="ViewInfoContainer"/> <see cref="Type"/>.</returns>
+        protected virtual Type GetViewInfoContainerType(AssemblyPart assemblyPart)
+        {
+            var precompiledAssemblyName = new AssemblyName(assemblyPart.Assembly.FullName);
+            precompiledAssemblyName.Name = precompiledAssemblyName.Name + PrecompiledViewsAssemblySuffix;
+
+            var typeName = $"{ViewInfoContainerNamespace}.{ViewInfoContainerTypeName},{precompiledAssemblyName}";
+            return Type.GetType(typeName);
+        }
     }
 }

test/Microsoft.AspNetCore.Mvc.Razor.Test/Compilation/ViewsFeatureProviderTest.cs

@@ -1,9 +1,11 @@
 // 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 System.Linq;
 using System.Reflection;
 using Microsoft.AspNetCore.Mvc.ApplicationParts;
-using Moq;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Mvc.Razor.Compilation
@@ -18,49 +20,89 @@ public void PopulateFeature_ReturnsEmptySequenceIfNoAssemblyPartHasViewAssembly(
             applicationPartManager.ApplicationParts.Add(
                 new AssemblyPart(typeof(ViewsFeatureProviderTest).GetTypeInfo().Assembly));
             applicationPartManager.FeatureProviders.Add(new ViewsFeatureProvider());
-            var feature = new MetadataReferenceFeature();
+            var feature = new ViewsFeature();
 
             // Act
             applicationPartManager.PopulateFeature(feature);
 
             // Assert
-            Assert.Empty(feature.MetadataReferences);
+            Assert.Empty(feature.Views);
         }
 
         [Fact]
         public void PopulateFeature_ReturnsViewsFromAllAvailableApplicationParts()
         {
             // Arrange
-            var applicationPart1 = new Mock<ApplicationPart>();
-            var viewsProvider1 = applicationPart1
-                .As<IViewsProvider>()
-                .SetupGet(p => p.Views)
-                .Returns(new[]
-                {
-                    new ViewInfo("/Views/test/Index.cshtml", typeof(object))
-                });
-            var applicationPart2 = new Mock<ApplicationPart>();
-            var viewsProvider2 = applicationPart2
-                .As<IViewsProvider>()
-                .SetupGet(p => p.Views)
-                .Returns(new[]
-                {
-                    new ViewInfo("/Areas/Admin/Views/Index.cshtml", typeof(string)),
-                    new ViewInfo("/Areas/Admin/Views/About.cshtml", typeof(int))
-                });
-
+            var part1 = new AssemblyPart(typeof(object).GetTypeInfo().Assembly);
+            var part2 = new AssemblyPart(GetType().GetTypeInfo().Assembly);
+            var featureProvider = new TestableViewsFeatureProvider(new Dictionary<AssemblyPart, Type>
+            {
+                { part1, typeof(ViewInfoContainer1) },
+                { part2, typeof(ViewInfoContainer2) },
+            });
 
             var applicationPartManager = new ApplicationPartManager();
-            applicationPartManager.ApplicationParts.Add(applicationPart1.Object);
-            applicationPartManager.ApplicationParts.Add(applicationPart2.Object);
-            applicationPartManager.FeatureProviders.Add(new ViewsFeatureProvider());
-            var feature = new MetadataReferenceFeature();
+            applicationPartManager.ApplicationParts.Add(part1);
+            applicationPartManager.ApplicationParts.Add(part2);
+            applicationPartManager.FeatureProviders.Add(featureProvider);
+            var feature = new ViewsFeature();
 
             // Act
             applicationPartManager.PopulateFeature(feature);
 
             // Assert
-            Assert.Empty(feature.MetadataReferences);
+            Assert.Collection(feature.Views.OrderBy(f => f.Key, StringComparer.Ordinal),
+                view =>
+                {
+                    Assert.Equal("/Areas/Admin/Views/About.cshtml", view.Key);
+                    Assert.Equal(typeof(int), view.Value);
+                },
+                view =>
+                {
+                    Assert.Equal("/Areas/Admin/Views/Index.cshtml", view.Key);
+                    Assert.Equal(typeof(string), view.Value);
+                },
+                view =>
+                {
+                    Assert.Equal("/Views/test/Index.cshtml", view.Key);
+                    Assert.Equal(typeof(object), view.Value);
+                });
+        }
+
+        private class TestableViewsFeatureProvider : ViewsFeatureProvider
+        {
+            private readonly Dictionary<AssemblyPart, Type> _containerLookup;
+
+            public TestableViewsFeatureProvider(Dictionary<AssemblyPart, Type> containerLookup)
+            {
+                _containerLookup = containerLookup;
+            }
+
+            protected override Type GetViewInfoContainerType(AssemblyPart assemblyPart)
+                => _containerLookup[assemblyPart];
+        }
+
+        private class ViewInfoContainer1 : ViewInfoContainer
+        {
+            public ViewInfoContainer1()
+                : base(new[]
+                {
+                    new ViewInfo("/Views/test/Index.cshtml", typeof(object))
+                })
+            {
+            }
+        }
+
+        private class ViewInfoContainer2 : ViewInfoContainer
+        {
+            public ViewInfoContainer2()
+                : base(new[]
+                {
+                    new ViewInfo("/Areas/Admin/Views/Index.cshtml", typeof(string)),
+                    new ViewInfo("/Areas/Admin/Views/About.cshtml", typeof(int))
+                })
+            {
+            }
         }
     }
 }