Fails to recognize existing GlobalSuppressions.cs having using directive

src/EditorFeatures/CSharpTest/Diagnostics/Suppression/SuppressionTests.cs

@@ -1539,6 +1539,39 @@ class Class { }
 [assembly: System.Diagnostics.CodeAnalysis.SuppressMessage(""InfoDiagnostic"", ""InfoDiagnostic:InfoDiagnostic"", Justification = ""<Pending>"", Scope = ""type"", Target = ""Class"")]
 [assembly: System.Diagnostics.CodeAnalysis.SuppressMessage(""InfoDiagnostic"", ""InfoDiagnostic:InfoDiagnostic"", Justification = ""{FeaturesResources.Pending}"", Scope = ""type"", Target = ""~T:Class2"")]
 
+";
+
+                    await TestAsync(initialMarkup, expectedText);
+                }
+
+                [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsSuppression)]
+                public async Task TestSuppressionWithUsingDirectiveInExistingGlobalSuppressionsDocument()
+                {
+                    var initialMarkup = @"<Workspace>
+    <Project Language=""C#"" CommonReferences=""true"" AssemblyName=""Proj1"">
+        <Document FilePath=""CurrentDocument.cs""><![CDATA[
+using System;
+
+class Class { }
+
+[|class Class2|] { }
+]]>
+        </Document>
+        <Document FilePath=""GlobalSuppressions.cs""><![CDATA[
+using System.Diagnostics.CodeAnalysis;
+
+[assembly: SuppressMessage(""InfoDiagnostic"", ""InfoDiagnostic:InfoDiagnostic"", Justification = ""<Pending>"", Scope = ""type"", Target = ""Class"")]
+]]>
+        </Document>
+    </Project>
+</Workspace>";
+                    var expectedText =
+                        $@"
+using System.Diagnostics.CodeAnalysis;
+
+[assembly: SuppressMessage(""InfoDiagnostic"", ""InfoDiagnostic:InfoDiagnostic"", Justification = ""<Pending>"", Scope = ""type"", Target = ""Class"")]
+[assembly: SuppressMessage(""InfoDiagnostic"", ""InfoDiagnostic:InfoDiagnostic"", Justification = ""{FeaturesResources.Pending}"", Scope = ""type"", Target = ""~T:Class2"")]
+
 ";
 
                     await TestAsync(initialMarkup, expectedText);

src/EditorFeatures/VisualBasicTest/Diagnostics/Suppression/SuppressionTests.vb

@@ -1558,6 +1558,39 @@ End Class
 
 <Assembly: Diagnostics.CodeAnalysis.SuppressMessage(""InfoDiagnostic"", ""InfoDiagnostic:InfoDiagnostic"", Justification:=""<Pending>"", Scope:=""type"", Target:=""Class1"")>
 <Assembly: System.Diagnostics.CodeAnalysis.SuppressMessage(""InfoDiagnostic"", ""InfoDiagnostic:InfoDiagnostic"", Justification:=""{FeaturesResources.Pending}"", Scope:=""type"", Target:=""~T:Class2"")>
+"
+
+                    Await TestAsync(source.ToString(), expected)
+                End Function
+
+                <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsSuppression)>
+                Public Async Function TestSuppressionWithUsingDirectiveInExistingGlobalSuppressionsDocument() As Task
+                    Dim source =
+                    <Workspace>
+                        <Project Language="Visual Basic" CommonReferences="true">
+                            <Document FilePath="CurrentDocument.vb"><![CDATA[
+Imports System
+
+Class Class1
+End Class
+
+[|Class Class2|]
+End Class]]>
+                            </Document>
+                            <Document FilePath="GlobalSuppressions.vb"><![CDATA[
+Imports System.Diagnostics.CodeAnalysis
+
+<Assembly: SuppressMessage("InfoDiagnostic", "InfoDiagnostic:InfoDiagnostic", Justification:="<Pending>", Scope:="type", Target:="Class1")>
+]]>
+                            </Document>
+                        </Project>
+                    </Workspace>
+
+                    Dim expected = $"
+Imports System.Diagnostics.CodeAnalysis
+
+<Assembly: SuppressMessage(""InfoDiagnostic"", ""InfoDiagnostic:InfoDiagnostic"", Justification:=""<Pending>"", Scope:=""type"", Target:=""Class1"")>
+<Assembly: SuppressMessage(""InfoDiagnostic"", ""InfoDiagnostic:InfoDiagnostic"", Justification:=""{FeaturesResources.Pending}"", Scope:=""type"", Target:=""~T:Class2"")>
 "
 
                     Await TestAsync(source.ToString(), expected)