From b1cc0da5012d9324f477d56327fe85b6357566c3 Mon Sep 17 00:00:00 2001
From: Yifan Zhu <yifzhu@microsoft.com>
Date: Sun, 15 Sep 2024 18:42:40 +0800
Subject: [PATCH 1/2] Add NullRedactor to the RedactorProvider during
 initialization.  Fix #5265

---
 .../RedactorProvider.cs                       |  8 +++++++
 .../RedactorProviderTests.cs                  | 24 ++++++++++++++-----
 2 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/src/Libraries/Microsoft.Extensions.Compliance.Redaction/RedactorProvider.cs b/src/Libraries/Microsoft.Extensions.Compliance.Redaction/RedactorProvider.cs
index 0963784fa80..6c307e8a1fe 100644
--- a/src/Libraries/Microsoft.Extensions.Compliance.Redaction/RedactorProvider.cs
+++ b/src/Libraries/Microsoft.Extensions.Compliance.Redaction/RedactorProvider.cs
@@ -5,6 +5,7 @@
 using System.Collections.Frozen;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
+using System.Linq;
 using Microsoft.Extensions.Compliance.Classification;
 using Microsoft.Extensions.Options;
 using Microsoft.Shared.Diagnostics;
@@ -37,6 +38,12 @@ public Redactor GetRedactor(DataClassificationSet classifications)
 
     private static FrozenDictionary<DataClassificationSet, Redactor> GetClassRedactorMap(IEnumerable<Redactor> redactors, Dictionary<DataClassificationSet, Type> map)
     {
+        if (!map.ContainsKey(DataClassification.None))
+        {
+            map.Add(DataClassification.None, typeof(NullRedactor));
+            redactors = redactors.Concat([NullRedactor.Instance]);
+        }
+
         var dict = new Dictionary<DataClassificationSet, Redactor>(map.Count);
         foreach (var m in map)
         {
@@ -45,6 +52,7 @@ private static FrozenDictionary<DataClassificationSet, Redactor> GetClassRedacto
                 if (r.GetType() == m.Value)
                 {
                     dict[m.Key] = r;
+                    break;
                 }
             }
         }
diff --git a/test/Libraries/Microsoft.Extensions.Compliance.Redaction.Tests/RedactorProviderTests.cs b/test/Libraries/Microsoft.Extensions.Compliance.Redaction.Tests/RedactorProviderTests.cs
index 0a7c97f34f1..9a69e83be50 100644
--- a/test/Libraries/Microsoft.Extensions.Compliance.Redaction.Tests/RedactorProviderTests.cs
+++ b/test/Libraries/Microsoft.Extensions.Compliance.Redaction.Tests/RedactorProviderTests.cs
@@ -10,6 +10,16 @@ namespace Microsoft.Extensions.Compliance.Redaction.Test;
 
 public class RedactorProviderTests
 {
+    [Fact]
+    public void RedactorProvider_Returns_NullRedactor_For_NoneDataClassification()
+    {
+        var redactorProvider = new RedactorProvider(
+            redactors: [ErasingRedactor.Instance],
+            options: Microsoft.Extensions.Options.Options.Create(new RedactorProviderOptions()));
+
+        Assert.IsType<NullRedactor>(redactorProvider.GetRedactor(DataClassification.None));
+    }
+
     [Fact]
     public void RedactorProvider_Returns_Redactor_For_Every_Data_Classification()
     {
@@ -38,13 +48,15 @@ public void RedactorProvider_Returns_Redactor_For_Data_Classifications()
             redactors: new Redactor[] { ErasingRedactor.Instance, NullRedactor.Instance },
             options: Microsoft.Extensions.Options.Options.Create(opt));
 
-        var r1 = redactorProvider.GetRedactor(_dataClassification1);
-        var r2 = redactorProvider.GetRedactor(_dataClassification2);
-        var r3 = redactorProvider.GetRedactor(_dataClassification3);
+        Redactor r1 = redactorProvider.GetRedactor(_dataClassification1);
+        Redactor r2 = redactorProvider.GetRedactor(_dataClassification2);
+        Redactor r3 = redactorProvider.GetRedactor(_dataClassification3);
+        Redactor r4 = redactorProvider.GetRedactor(DataClassification.None);
 
-        Assert.Equal(typeof(ErasingRedactor), r1.GetType());
-        Assert.Equal(typeof(NullRedactor), r2.GetType());
-        Assert.Equal(typeof(ErasingRedactor), r3.GetType());
+        Assert.IsType<ErasingRedactor>(r1);
+        Assert.IsType<NullRedactor>(r2);
+        Assert.IsType<ErasingRedactor>(r3);
+        Assert.IsType<NullRedactor>(r4);
     }
 
     [Fact]

From bc0a965e72b1d3d776265f4ede9f70bc37a93be5 Mon Sep 17 00:00:00 2001
From: Yifan Zhu <yifzhu@microsoft.com>
Date: Thu, 19 Sep 2024 19:54:17 +0800
Subject: [PATCH 2/2] Use spread operator to avoid the need of LINQ

---
 .../RedactorProvider.cs                                        | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/Libraries/Microsoft.Extensions.Compliance.Redaction/RedactorProvider.cs b/src/Libraries/Microsoft.Extensions.Compliance.Redaction/RedactorProvider.cs
index 6c307e8a1fe..18a356d1a10 100644
--- a/src/Libraries/Microsoft.Extensions.Compliance.Redaction/RedactorProvider.cs
+++ b/src/Libraries/Microsoft.Extensions.Compliance.Redaction/RedactorProvider.cs
@@ -5,7 +5,6 @@
 using System.Collections.Frozen;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
-using System.Linq;
 using Microsoft.Extensions.Compliance.Classification;
 using Microsoft.Extensions.Options;
 using Microsoft.Shared.Diagnostics;
@@ -41,7 +40,7 @@ private static FrozenDictionary<DataClassificationSet, Redactor> GetClassRedacto
         if (!map.ContainsKey(DataClassification.None))
         {
             map.Add(DataClassification.None, typeof(NullRedactor));
-            redactors = redactors.Concat([NullRedactor.Instance]);
+            redactors = [.. redactors, NullRedactor.Instance];
         }
 
         var dict = new Dictionary<DataClassificationSet, Redactor>(map.Count);