From 5a6bf2d9e92c5a7342006b0a041a04788ad153b6 Mon Sep 17 00:00:00 2001
From: Joey Robichaud <jorobich@microsoft.com>
Date: Mon, 8 Feb 2021 12:00:03 -0800
Subject: [PATCH] Isolate each Analyzer assembly by loading into its own
 context.

---
 .../AnalyzerReferenceInformationProvider.cs   |  4 +-
 .../ThirdPartyAnalyzerFormatterTests.cs       | 49 ++++++++++++++++++-
 .../analyzer_project/analyzer_project.csproj  |  1 +
 3 files changed, 50 insertions(+), 4 deletions(-)

diff --git a/src/Analyzers/AnalyzerReferenceInformationProvider.cs b/src/Analyzers/AnalyzerReferenceInformationProvider.cs
index eaae51abed..9ab076289d 100644
--- a/src/Analyzers/AnalyzerReferenceInformationProvider.cs
+++ b/src/Analyzers/AnalyzerReferenceInformationProvider.cs
@@ -23,10 +23,8 @@ internal class AnalyzerReferenceInformationProvider : IAnalyzerInformationProvid
 
         private AnalyzersAndFixers GetAnalyzersAndFixers(Project project)
         {
-            var context = new AnalyzerLoadContext();
-
             var analyzerAssemblies = project.AnalyzerReferences
-                .Select(reference => TryLoadAssemblyFrom(reference.FullPath, context))
+                .Select(reference => TryLoadAssemblyFrom(reference.FullPath, new AnalyzerLoadContext()))
                 .OfType<Assembly>()
                 .ToImmutableArray();
 
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>