diff --git a/eng/Versions.props b/eng/Versions.props
index 106d12fb72c13..6db4d3d6970bb 100644
--- a/eng/Versions.props
+++ b/eng/Versions.props
@@ -28,7 +28,7 @@
     <!-- Versions used by several individual references below -->
     <RoslynDiagnosticsNugetPackageVersion>3.0.0-beta2.20059.3+77df2220</RoslynDiagnosticsNugetPackageVersion>
     <CodeStyleLayerCodeAnalysisVersion>3.3.1</CodeStyleLayerCodeAnalysisVersion>
-    <MicrosoftCodeAnalysisTestingVersion>1.0.1-beta1.20114.4</MicrosoftCodeAnalysisTestingVersion>
+    <MicrosoftCodeAnalysisTestingVersion>1.0.1-beta1.20118.1</MicrosoftCodeAnalysisTestingVersion>
     <CodeStyleAnalyzerVersion>3.5.0-beta3-20078-04</CodeStyleAnalyzerVersion>
     <VisualStudioEditorPackagesVersion>16.4.248</VisualStudioEditorPackagesVersion>
     <ILToolsPackageVersion>5.0.0-alpha1.19409.1</ILToolsPackageVersion>
diff --git a/src/EditorFeatures/CSharpTest/AddObsoleteAttribute/AddObsoleteAttributeTests.cs b/src/EditorFeatures/CSharpTest/AddObsoleteAttribute/AddObsoleteAttributeTests.cs
index cc872b0f6f4a8..b6a13e8e09a14 100644
--- a/src/EditorFeatures/CSharpTest/AddObsoleteAttribute/AddObsoleteAttributeTests.cs
+++ b/src/EditorFeatures/CSharpTest/AddObsoleteAttribute/AddObsoleteAttributeTests.cs
@@ -3,29 +3,25 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis.CodeFixes;
-using Microsoft.CodeAnalysis.CSharp.AddObsoleteAttribute;
-using Microsoft.CodeAnalysis.Diagnostics;
-using Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.Diagnostics;
 using Microsoft.CodeAnalysis.Test.Utilities;
 using Xunit;
+using VerifyCS = Microsoft.CodeAnalysis.Editor.UnitTests.CodeActions.CSharpCodeFixVerifier<
+    Microsoft.CodeAnalysis.Testing.EmptyDiagnosticAnalyzer,
+    Microsoft.CodeAnalysis.CSharp.AddObsoleteAttribute.CSharpAddObsoleteAttributeCodeFixProvider>;
 
 namespace Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.AddObsoleteAttribute
 {
-    public class AddObsoleteAttributeTests : AbstractCSharpDiagnosticProviderBasedUserDiagnosticTest
+    public class AddObsoleteAttributeTests
     {
-        internal override (DiagnosticAnalyzer, CodeFixProvider) CreateDiagnosticProviderAndFixer(Workspace workspace)
-            => (null, new CSharpAddObsoleteAttributeCodeFixProvider());
-
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsAddObsoleteAttribute)]
         public async Task TestObsoleteClassNoMessage()
         {
-            await TestInRegularAndScript1Async(
+            await VerifyCS.VerifyCodeFixAsync(
 @"
 [System.Obsolete]
 class Base {}
 
-class Derived : [||]Base {
+class Derived : {|CS0612:Base|} {
 }
 ",
 @"
@@ -41,12 +37,12 @@ class Derived : Base {
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsAddObsoleteAttribute)]
         public async Task TestObsoleteClassWithMessage()
         {
-            await TestInRegularAndScript1Async(
+            await VerifyCS.VerifyCodeFixAsync(
 @"
 [System.Obsolete(""message"")]
 class Base {}
 
-class Derived : [||]Base {
+class Derived : {|CS0618:Base|} {
 }
 ",
 @"
@@ -62,12 +58,12 @@ class Derived : Base {
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsAddObsoleteAttribute)]
         public async Task TestObsoleteClassWithMessageAndErrorFalse()
         {
-            await TestInRegularAndScript1Async(
+            await VerifyCS.VerifyCodeFixAsync(
 @"
 [System.Obsolete(""message"", error: false)]
 class Base {}
 
-class Derived : [||]Base {
+class Derived : {|CS0618:Base|} {
 }
 ",
 @"
@@ -83,26 +79,26 @@ class Derived : Base {
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsAddObsoleteAttribute)]
         public async Task TestObsoleteClassWithMessageAndErrorTrue()
         {
-            await TestMissingInRegularAndScriptAsync(
-@"
+            var code = @"
 [System.Obsolete(""message"", error: true)]
 class Base {}
 
-class Derived : [||]Base {
+class Derived : {|CS0619:Base|} {
 }
-");
+";
+            await VerifyCS.VerifyCodeFixAsync(code, code);
         }
 
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsAddObsoleteAttribute)]
         public async Task TestObsoleteClassUsedInField()
         {
-            await TestInRegularAndScript1Async(
+            await VerifyCS.VerifyCodeFixAsync(
 @"
 [System.Obsolete]
 class Base { public static int i; }
 
 class Derived {
-    int i = [||]Base.i;
+    int i = {|CS0612:Base|}.i;
 }
 ",
 @"
@@ -119,14 +115,14 @@ class Derived {
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsAddObsoleteAttribute)]
         public async Task TestObsoleteClassUsedInMethod()
         {
-            await TestInRegularAndScript1Async(
+            await VerifyCS.VerifyCodeFixAsync(
 @"
 [System.Obsolete]
 class Base { public static int i; }
 
 class Derived {
     void Goo() {
-        int i = [||]Base.i;
+        int i = {|CS0612:Base|}.i;
     }
 }
 ",
@@ -146,7 +142,7 @@ void Goo() {
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsAddObsoleteAttribute)]
         public async Task TestObsoleteOverride()
         {
-            await TestInRegularAndScript1Async(
+            await VerifyCS.VerifyCodeFixAsync(
 @"
 class Base { 
     [System.Obsolete]
@@ -154,7 +150,7 @@ protected virtual void ObMethod() { }
 }
 
 class Derived : Base {
-    protected override void [||]ObMethod() { }
+    protected override void {|CS0672:ObMethod|}() { }
 }
 ",
 @"
@@ -173,15 +169,15 @@ protected override void ObMethod() { }
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsAddObsoleteAttribute)]
         public async Task TestObsoleteClassFixAll1()
         {
-            await TestInRegularAndScript1Async(
+            await VerifyCS.VerifyCodeFixAsync(
 @"
 [System.Obsolete]
 class Base { public static int i; }
 
 class Derived {
     void Goo() {
-        int i = {|FixAllInDocument:|}Base.i;
-        int j = Base.i;
+        int i = {|CS0612:Base|}.i;
+        int j = {|CS0612:Base|}.i;
     }
 }
 ",
@@ -202,15 +198,15 @@ void Goo() {
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsAddObsoleteAttribute)]
         public async Task TestObsoleteClassFixAll2()
         {
-            await TestInRegularAndScript1Async(
+            await VerifyCS.VerifyCodeFixAsync(
 @"
 [System.Obsolete]
 class Base { public static int i; }
 
 class Derived {
     void Goo() {
-        int i = Base.i;
-        int j = {|FixAllInDocument:|}Base.i;
+        int i = {|CS0612:Base|}.i;
+        int j = {|CS0612:Base|}.i;
     }
 }
 ",
@@ -231,18 +227,18 @@ void Goo() {
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsAddObsoleteAttribute)]
         public async Task TestObsoleteClassFixAll3()
         {
-            await TestInRegularAndScript1Async(
+            await VerifyCS.VerifyCodeFixAsync(
 @"
 [System.Obsolete]
 class Base { public static int i; }
 
 class Derived {
     void Goo() {
-        int i = {|FixAllInDocument:|}Base.i;
+        int i = {|CS0612:Base|}.i;
     }
 
     void Bar() {
-        int j = Base.i;
+        int j = {|CS0612:Base|}.i;
     }
 }
 ",
@@ -267,17 +263,20 @@ void Bar() {
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsAddObsoleteAttribute)]
         public async Task TestObsoleteCollectionAddMethod()
         {
-            await TestInRegularAndScript1Async(
+            await VerifyCS.VerifyCodeFixAsync(
 @"
 class Collection : System.Collections.Generic.IEnumerable<int> {
     [System.Obsolete]
     public void Add(int i) { }
+
+    public System.Collections.Generic.IEnumerator<int> GetEnumerator() => throw null;
+    System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() => throw null;
 }
 
 class Derived {
     void Goo() {
         var c = new Collection {
-            [||]1, 2, 3
+            {|CS1064:1|}, {|CS1064:2|}, {|CS1064:3|}
         };
     }
 }
@@ -286,6 +285,9 @@ void Goo() {
 class Collection : System.Collections.Generic.IEnumerable<int> {
     [System.Obsolete]
     public void Add(int i) { }
+
+    public System.Collections.Generic.IEnumerator<int> GetEnumerator() => throw null;
+    System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() => throw null;
 }
 
 class Derived {
@@ -302,17 +304,20 @@ void Goo() {
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsAddObsoleteAttribute)]
         public async Task TestObsoleteCollectionAddMethodWithMessage()
         {
-            await TestInRegularAndScript1Async(
+            await VerifyCS.VerifyCodeFixAsync(
 @"
 class Collection : System.Collections.Generic.IEnumerable<int> {
     [System.Obsolete(""message"")]
     public void Add(int i) { }
+
+    public System.Collections.Generic.IEnumerator<int> GetEnumerator() => throw null;
+    System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() => throw null;
 }
 
 class Derived {
     void Goo() {
         var c = new Collection {
-            [||]1, 2, 3
+            {|CS1062:1|}, {|CS1062:2|}, {|CS1062:3|}
         };
     }
 }
@@ -321,6 +326,9 @@ void Goo() {
 class Collection : System.Collections.Generic.IEnumerable<int> {
     [System.Obsolete(""message"")]
     public void Add(int i) { }
+
+    public System.Collections.Generic.IEnumerator<int> GetEnumerator() => throw null;
+    System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() => throw null;
 }
 
 class Derived {
@@ -337,17 +345,20 @@ void Goo() {
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsAddObsoleteAttribute)]
         public async Task TestObsoleteCollectionAddMethodWithMessageAndErrorFalse()
         {
-            await TestInRegularAndScript1Async(
+            await VerifyCS.VerifyCodeFixAsync(
 @"
 class Collection : System.Collections.Generic.IEnumerable<int> {
     [System.Obsolete(""message"", error: false)]
     public void Add(int i) { }
+
+    public System.Collections.Generic.IEnumerator<int> GetEnumerator() => throw null;
+    System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() => throw null;
 }
 
 class Derived {
     void Goo() {
         var c = new Collection {
-            [||]1, 2, 3
+            {|CS1062:1|}, {|CS1062:2|}, {|CS1062:3|}
         };
     }
 }
@@ -356,6 +367,9 @@ void Goo() {
 class Collection : System.Collections.Generic.IEnumerable<int> {
     [System.Obsolete(""message"", error: false)]
     public void Add(int i) { }
+
+    public System.Collections.Generic.IEnumerator<int> GetEnumerator() => throw null;
+    System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() => throw null;
 }
 
 class Derived {
@@ -372,21 +386,25 @@ void Goo() {
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsAddObsoleteAttribute)]
         public async Task TestObsoleteCollectionAddMethodWithMessageAndErrorTrue()
         {
-            await TestMissingInRegularAndScriptAsync(
-@"
+            var code = @"
 class Collection : System.Collections.Generic.IEnumerable<int> {
     [System.Obsolete(""message"", error: true)]
     public void Add(int i) { }
+
+    public System.Collections.Generic.IEnumerator<int> GetEnumerator() => throw null;
+    System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() => throw null;
 }
 
 class Derived {
     void Goo() {
         var c = new Collection {
-            [||]1, 2, 3
+            {|CS1063:1|}, {|CS1063:2|}, {|CS1063:3|}
         };
     }
 }
-");
+";
+
+            await VerifyCS.VerifyCodeFixAsync(code, code);
         }
     }
 }