From ae02df0074b3d05f63d5f4667e367fad99613c7d Mon Sep 17 00:00:00 2001
From: Joey Robichaud <jorobich@microsoft.com>
Date: Mon, 8 Feb 2021 12:00:03 -0800
Subject: [PATCH] Search all Analyzer assembly paths when resolving
 dependencies

---
 .../AnalyzerReferenceInformationProvider.cs   | 25 +++++++---
 .../ThirdPartyAnalyzerFormatterTests.cs       | 49 ++++++++++++++++++-
 .../analyzer_project/analyzer_project.csproj  |  1 +
 3 files changed, 67 insertions(+), 8 deletions(-)

diff --git a/src/Analyzers/AnalyzerReferenceInformationProvider.cs b/src/Analyzers/AnalyzerReferenceInformationProvider.cs
index eaae51abed..95d54ab68d 100644
--- a/src/Analyzers/AnalyzerReferenceInformationProvider.cs
+++ b/src/Analyzers/AnalyzerReferenceInformationProvider.cs
@@ -1,5 +1,6 @@
 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the MIT license.  See License.txt in the project root for license information.
 
+using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.IO;
 using System.Linq;
@@ -43,7 +44,9 @@ private AnalyzersAndFixers GetAnalyzersAndFixers(Project project)
 
             try
             {
-                context.AssemblyFolderPath = Path.GetDirectoryName(path);
+                // Until types are realized not all dependencies are loaded. Track each
+                // assembly's path as a search path when resolving dependencies.
+                context.AddSearchPath(Path.GetDirectoryName(path));
 
                 // First try loading the assembly from disk.
                 return context.LoadFromAssemblyPath(path);
@@ -58,7 +61,12 @@ private AnalyzersAndFixers GetAnalyzersAndFixers(Project project)
 
         internal sealed class AnalyzerLoadContext : AssemblyLoadContext
         {
-            internal string AssemblyFolderPath { get; set; } = string.Empty;
+            internal readonly HashSet<string> _searchPaths = new HashSet<string>();
+
+            internal void AddSearchPath(string path)
+            {
+                _searchPaths.Add(path);
+            }
 
             protected override Assembly Load(AssemblyName assemblyName)
             {
@@ -68,12 +76,15 @@ protected override Assembly Load(AssemblyName assemblyName)
 
                 try
                 {
-                    // Search for assembly based on assembly name and culture within the analyzer folder.
-                    var assembly = AssemblyResolver.TryResolveAssemblyFromPaths(this, assemblyName, AssemblyFolderPath);
-
-                    if (assembly != null)
+                    foreach (var searchPath in _searchPaths)
                     {
-                        return assembly;
+                        // Search for assembly based on assembly name and culture within the analyzer folder.
+                        var assembly = AssemblyResolver.TryResolveAssemblyFromPaths(this, assemblyName, searchPath);
+
+                        if (assembly != null)
+                        {
+                            return assembly;
+                        }
                     }
                 }
                 catch { }
diff --git a/tests/Analyzers/ThirdPartyAnalyzerFormatterTests.cs b/tests/Analyzers/ThirdPartyAnalyzerFormatterTests.cs
index 3d463bd730..f430e9d6af 100644
--- a/tests/Analyzers/ThirdPartyAnalyzerFormatterTests.cs
+++ b/tests/Analyzers/ThirdPartyAnalyzerFormatterTests.cs
@@ -120,7 +120,7 @@ void M()
         }
 
         [Fact]
-        public async Task TestIDisposableAnalyzer_Loads()
+        public async Task TestIDisposableAnalyzer_AddsUsing()
         {
             var analyzerReferences = GetAnalyzerReferences("IDisposable");
 
@@ -141,6 +141,53 @@ void M()
             var expectedCode = @"
 using System.IO;
 
+class C
+{
+    void M()
+    {
+        using (var stream = File.OpenRead(string.Empty))
+        {
+            var b = stream.ReadByte();
+        }
+    }
+}
+";
+
+            var editorConfig = new Dictionary<string, string>()
+            {
+                // Turn off all diagnostics analyzers
+                ["dotnet_analyzer_diagnostic.severity"] = "none",
+
+                // Prefer using. IDISP017
+                ["dotnet_diagnostic.IDISP017.severity"] = "error",
+            };
+
+            await AssertCodeChangedAsync(testCode, expectedCode, editorConfig, fixCategory: FixCategory.Analyzers, analyzerReferences: analyzerReferences);
+        }
+
+        [Fact]
+        public async Task TestLoadingAllAnalyzers_LoadsDependenciesFromAllSearchPaths()
+        {
+            // Loads all analyzer references.
+            var analyzerReferences = _analyzerReferencesProject.AnalyzerReferences;
+
+            var testCode = @"
+using System.IO;
+
+class C
+{
+    void M()
+    {
+        var stream = File.OpenRead(string.Empty);
+        var b = stream.ReadByte();
+        stream.Dispose();
+    }
+}
+";
+
+            var expectedCode = @"
+using System.IO;
+
 class C
 {
     void M()
diff --git a/tests/projects/for_analyzer_formatter/analyzer_project/analyzer_project.csproj b/tests/projects/for_analyzer_formatter/analyzer_project/analyzer_project.csproj
index b106a32018..ad9d39ed6d 100644
--- a/tests/projects/for_analyzer_formatter/analyzer_project/analyzer_project.csproj
+++ b/tests/projects/for_analyzer_formatter/analyzer_project/analyzer_project.csproj
@@ -9,6 +9,7 @@
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
     </PackageReference>
+    <PackageReference Include="AspNetCoreAnalyzers" Version="0.2.0.1-dev" PrivateAssets="all" />
     <PackageReference Include="IDisposableAnalyzers" Version="3.4.8" PrivateAssets="all" />
   </ItemGroup>