Add assembly name filtering to GetTagHelpers calls.

- Updated the Razor extension to properly discover all assembly names available to a project and use those as a TagHelper filter.

#1022

src/Microsoft.CodeAnalysis.Razor.Workspaces/DefaultTagHelperResolver.cs

@@ -5,6 +5,7 @@ using System;
 using System.Collections.Generic;
 using Microsoft.AspNetCore.Razor.Evolution;
 using Microsoft.AspNetCore.Razor.Evolution.Legacy;
+using System.Linq;
 
 namespace Microsoft.CodeAnalysis.Razor
 {
@@ -17,12 +18,12 @@ namespace Microsoft.CodeAnalysis.Razor
 
         public bool DesignTime { get; }
 
-        public override TagHelperResolutionResult GetTagHelpers(Compilation compilation)
+        public override TagHelperResolutionResult GetTagHelpers(Compilation compilation, IEnumerable<string> assemblyNameFilters)
         {
             var descriptors = new List<TagHelperDescriptor>();
             var errors = new ErrorSink();
 
-            VisitTagHelpers(compilation, descriptors, errors);
+            VisitTagHelpers(compilation, assemblyNameFilters, descriptors, errors);
             VisitViewComponents(compilation, descriptors, errors);
 
             var diagnostics = new List<RazorDiagnostic>();
@@ -36,7 +37,7 @@ namespace Microsoft.CodeAnalysis.Razor
             return resolutionResult;
         }
 
-        private void VisitTagHelpers(Compilation compilation, List<TagHelperDescriptor> results, ErrorSink errors)
+        private void VisitTagHelpers(Compilation compilation, IEnumerable<string> assemblyNameFilters, List<TagHelperDescriptor> results, ErrorSink errors)
         {
             var types = new List<INamedTypeSymbol>();
             var visitor = TagHelperTypeVisitor.Create(compilation, types);
@@ -47,12 +48,15 @@ namespace Microsoft.CodeAnalysis.Razor
 
             foreach (var type in types)
             {
-                var descriptors = factory.CreateDescriptors(type, errors);
+                if (assemblyNameFilters.Contains(type.ContainingAssembly.Identity.Name))
-                results.AddRange(descriptors);
+                {
+                    var descriptors = factory.CreateDescriptors(type, errors);
+                    results.AddRange(descriptors);
+                }
             }
         }
 
-        private void VisitViewComponents(Compilation compilation, List<TagHelperDescriptor> results, ErrorSink errors)
+        private void VisitViewComponents(Compilation compilation, IEnumerable<string> assemblyNameFilters, List<TagHelperDescriptor> results, ErrorSink errors)
         {
             var types = new List<INamedTypeSymbol>();
             var visitor = ViewComponentTypeVisitor.Create(compilation, types);
@@ -65,9 +69,12 @@ namespace Microsoft.CodeAnalysis.Razor
             {
                 try
                 {
-                    var descriptor = factory.CreateDescriptor(type);
+                    if (assemblyNameFilters.Contains(type.ContainingAssembly.Identity.Name))
+                    {
+                        var descriptor = factory.CreateDescriptor(type);
 
-                    results.Add(descriptor);
+                        results.Add(descriptor);
+                    }
                 }
                 catch (Exception ex)
                 {

src/Microsoft.CodeAnalysis.Razor.Workspaces/TagHelperResolver.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.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis.Host;
@@ -9,14 +10,15 @@ namespace Microsoft.CodeAnalysis.Razor
 {
     internal abstract class TagHelperResolver : ILanguageService
     {
-        public abstract TagHelperResolutionResult GetTagHelpers(Compilation compilation);
+        public abstract TagHelperResolutionResult GetTagHelpers(Compilation compilation, IEnumerable<string> assemblyNameFilters);
 
         public virtual async Task<TagHelperResolutionResult> GetTagHelpersAsync(
             Project project,
+            IEnumerable<string> assemblyNameFilters,
             CancellationToken cancellationToken = default(CancellationToken))
         {
             var compilation = await project.GetCompilationAsync(cancellationToken).ConfigureAwait(false);
-            return GetTagHelpers(compilation);
+            return GetTagHelpers(compilation, assemblyNameFilters);
         }
     }
 }

src/Microsoft.CodeAnalysis.Remote.Razor/RazorLanguageService.cs

@@ -20,7 +20,7 @@ namespace Microsoft.CodeAnalysis.Remote.Razor
         {
         }
 
-        public async Task<TagHelperResolutionResult> GetTagHelpersAsync(Guid projectIdBytes, string projectDebugName, CancellationToken cancellationToken = default(CancellationToken))
+        public async Task<TagHelperResolutionResult> GetTagHelpersAsync(Guid projectIdBytes, string projectDebugName, IEnumerable<string> assemblyNameFilters, CancellationToken cancellationToken = default(CancellationToken))
         {
             var projectId = ProjectId.CreateFromSerialized(projectIdBytes, projectDebugName);
 
@@ -28,7 +28,7 @@ namespace Microsoft.CodeAnalysis.Remote.Razor
             var project = solution.GetProject(projectId);
 
             var resolver = new DefaultTagHelperResolver(designTime: true);
-            var result = await resolver.GetTagHelpersAsync(project, cancellationToken).ConfigureAwait(false);
+            var result = await resolver.GetTagHelpersAsync(project, assemblyNameFilters, cancellationToken).ConfigureAwait(false);
 
             return result;
         }

src/Microsoft.VisualStudio.LanguageServices.Razor/DefaultTagHelperResolver.cs

@@ -6,7 +6,6 @@ using System.Collections.Generic;
 using System.Composition;
 using System.Threading;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Razor.Evolution;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.Razor;
 
@@ -18,7 +17,7 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor
         [Import]
         public VisualStudioWorkspace Workspace { get; set; }
 
-        public async Task<TagHelperResolutionResult> GetTagHelpersAsync(Project project)
+        public async Task<TagHelperResolutionResult> GetTagHelpersAsync(Project project, IEnumerable<string> assemblyNameFilters)
         {
             try
             {
@@ -27,13 +26,13 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor
                 {
                     // The OOP host is turned off, so let's do this in process.
                     var resolver = new CodeAnalysis.Razor.DefaultTagHelperResolver(designTime: true);
-                    var result =  await resolver.GetTagHelpersAsync(project, CancellationToken.None).ConfigureAwait(false);
+                    var result =  await resolver.GetTagHelpersAsync(project, assemblyNameFilters, CancellationToken.None).ConfigureAwait(false);
                     return result;
                 }
 
                 using (var session = await client.CreateSessionAsync(project.Solution))
                 {
-                    var result = await session.InvokeAsync<TagHelperResolutionResult>("GetTagHelpersAsync", new object[] { project.Id.Id, "Foo", }).ConfigureAwait(false);
+                    var result = await session.InvokeAsync<TagHelperResolutionResult>("GetTagHelpersAsync", new object[] { project.Id.Id, "Foo", assemblyNameFilters, }).ConfigureAwait(false);
                     return result;
                 }
             }

src/Microsoft.VisualStudio.LanguageServices.Razor/ITagHelperResolver.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.Collections.Generic;
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.Razor;
@@ -9,6 +10,6 @@ namespace Microsoft.VisualStudio.LanguageServices.Razor
 {
     public interface ITagHelperResolver
     {
-        Task<TagHelperResolutionResult> GetTagHelpersAsync(Project project);
+        Task<TagHelperResolutionResult> GetTagHelpersAsync(Project project, IEnumerable<string> assemblyNameFilters);
     }
 }

tooling/Microsoft.VisualStudio.RazorExtension/RazorInfo/RazorInfoViewModel.cs

@@ -14,6 +14,7 @@ using Microsoft.VisualStudio.LanguageServices.Razor;
 using Microsoft.VisualStudio.Shell;
 using Microsoft.VisualStudio.Shell.Interop;
 using Microsoft.VisualStudio.TextManager.Interop;
+using System.IO;
 
 namespace Microsoft.VisualStudio.RazorExtension.RazorInfo
 {
@@ -169,7 +170,14 @@ namespace Microsoft.VisualStudio.RazorExtension.RazorInfo
                 var assemblies = await _assemblyResolver.GetRazorEngineAssembliesAsync(project);
 
                 var directives = await _directiveResolver.GetRazorEngineDirectivesAsync(_workspace, project);
-                var resolutionResult = await _tagHelperResolver.GetTagHelpersAsync(project);
+                var assemblyFilters = project.MetadataReferences
+                    .Select(reference => reference.Display)
+                    .Select(filter => Path.GetFileNameWithoutExtension(filter));
+                var projectFilters = project.AllProjectReferences.Select(filter => solution.GetProject(filter.ProjectId).AssemblyName);
+                var tagHelperAssemblyFilters = assemblyFilters
+                    .Concat(projectFilters)
+                    .Concat(new[] { project.AssemblyName });
+                var resolutionResult = await _tagHelperResolver.GetTagHelpersAsync(project, tagHelperAssemblyFilters);
 
                 var files = GetCshtmlDocuments(project);