Rewrite PopulateSwitch diagnostic and fixes. Fix bug in generator that causes...

Rewrite PopulateSwitch diagnostic and fixes.  Fix bug in generator that causes crashes when generating a default case for VB.NET switches.

src/EditorFeatures/CSharpTest/CSharpEditorServicesTest.csproj

@@ -183,8 +183,8 @@
     <Compile Include="CodeActions\Preview\PreviewTests.cs" />
     <Compile Include="CodeActions\ReplaceMethodWithProperty\ReplaceMethodWithPropertyTests.cs" />
     <Compile Include="Diagnostics\InvokeDelegateWithConditionalAccess\InvokeDelegateWithConditionalAccessTests.cs" />
-    <Compile Include="Diagnostics\PopulateSwitch\PopulateSwitchTests.cs" />
-    <Compile Include="Diagnostics\PopulateSwitch\PopulateSwitchTests_FixAllTests.cs" />
+    <Compile Include="PopulateSwitch\PopulateSwitchTests.cs" />
+    <Compile Include="PopulateSwitch\PopulateSwitchTests_FixAllTests.cs" />
     <Compile Include="Diagnostics\Suppression\RemoveSuppressionTests.cs" />
     <Compile Include="Diagnostics\Suppression\SuppressionTest_FixMultipleTests.cs" />
     <Compile Include="Diagnostics\UseAutoProperty\UseAutoPropertyTests.cs" />

src/EditorFeatures/CSharpTest/Diagnostics/PopulateSwitch/PopulateSwitchTests.cs → src/EditorFeatures/CSharpTest/PopulateSwitch/PopulateSwitchTests.cs

@@ -14,7 +14,7 @@ public partial class PopulateSwitchTests : AbstractCSharpDiagnosticProviderBased
         internal override Tuple<DiagnosticAnalyzer, CodeFixProvider> CreateDiagnosticProviderAndFixer(Workspace workspace)
         {
             return new Tuple<DiagnosticAnalyzer, CodeFixProvider>(
-                new CSharpPopulateSwitchDiagnosticAnalyzer(), new PopulateSwitchCodeFixProvider());
+                new CSharpPopulateSwitchDiagnosticAnalyzer(), new CSharpPopulateSwitchCodeFixProvider());
         }
 
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsPopulateSwitch)]
@@ -33,13 +33,13 @@ class MyClass
         void Method()
         {
             var e = MyEnum.Fizz;
-            switch (e)
+            switch ([|e|])
             {
-                [|case MyEnum.Fizz:
+                case MyEnum.Fizz:
                 case MyEnum.Buzz:
                 case MyEnum.FizzBuzz:
                 default:
-                    break;|]
+                    break;
             }
         }
     }
@@ -63,12 +63,12 @@ class MyClass
         void Method()
         {
             var e = MyEnum.Fizz;
-            switch (e)
+            switch ([|e|])
             {
-                [|case MyEnum.Fizz:
+                case MyEnum.Fizz:
                 case MyEnum.Buzz:
                 case MyEnum.FizzBuzz:
-                    break;|]
+                    break;
             }
         }
     }
@@ -117,11 +117,11 @@ class MyClass
         void Method()
         {
             var e = MyEnum.Fizz;
-            switch (e)
+            switch ([|e|])
             {
-                [|case MyEnum.Fizz:
+                case MyEnum.Fizz:
                 case MyEnum.Buzz:
-                    break;|]
+                    break;
             }
         }
     }
@@ -171,13 +171,13 @@ class MyClass
         void Method()
         {
             var e = MyEnum.Fizz;
-            switch (e)
+            switch ([|e|])
             {
-                [|case MyEnum.Fizz:
+                case MyEnum.Fizz:
                 case MyEnum.Buzz:
                     break;
                 default:
-                    break;|]
+                    break;
             }
         }
     }
@@ -227,11 +227,11 @@ class MyClass
         void Method()
         {
             var e = MyEnum.Fizz;
-            switch (e)
+            switch ([|e|])
             {
-                [|case MyEnum.Fizz:
+                case MyEnum.Fizz:
                 case MyEnum.Buzz:
-                    break;|]
+                    break;
             }
         }
     }
@@ -281,12 +281,12 @@ class MyClass
         void Method()
         {
             var e = MyEnum.Fizz;
-            switch (e)
+            switch ([|e|])
             {
-                [|case MyEnum.Fizz:
+                case MyEnum.Fizz:
                 case MyEnum.Buzz:
                 default:
-                    break;|]
+                    break;
             }
         }
     }
@@ -335,13 +335,13 @@ class MyClass
         void Method()
         {
             var e = MyEnum.Fizz;
-            switch (e)
+            switch ([|e|])
             {
-                [|default:
+                default:
                     break;
                 case MyEnum.Fizz:
                 case MyEnum.Buzz:
-                    break;|]
+                    break;
             }
         }
     }
@@ -391,9 +391,8 @@ class MyClass
         void Method()
         {
             var e = MyEnum.Fizz;
-            switch (e)
+            switch ([|e|])
             {
-                [||]
             }
         }
     }
@@ -441,9 +440,9 @@ class MyClass
         void Method()
         {
             var e = Append;
-            switch (e)
+            switch ([|e|])
             {
-                [|case CreateNew:
+                case CreateNew:
                     break;
                 case Create:
                     break;
@@ -456,7 +455,7 @@ void Method()
                 case Append:
                     break;
                 default:
-                    break;|]
+                    break;
             }
         }
     }
@@ -477,9 +476,9 @@ class MyClass
         void Method()
         {
             var e = Append;
-            switch (e)
+            switch ([|e|])
             {
-                [|case CreateNew:
+                case CreateNew:
                     break;
                 case OpenOrCreate:
                     break;
@@ -492,7 +491,7 @@ void Method()
                 case Create:
                     break;
                 default:
-                    break;|]
+                    break;
             }
         }
     }
@@ -513,9 +512,9 @@ class MyClass
         void Method()
         {
             var e = Append;
-            switch (e)
+            switch ([|e|])
             {
-                [|case CreateNew:
+                case CreateNew:
                     break;
                 case Create:
                     break;
@@ -524,7 +523,7 @@ void Method()
                 case OpenOrCreate:
                     break;
                 default:
-                    break;|]
+                    break;
             }
         }
     }
@@ -549,9 +548,9 @@ void Method()
                     break;
                 case OpenOrCreate:
                     break;
-                case Append:
+                case System.IO.FileMode.Truncate:
                     break;
-                case Truncate:
+                case System.IO.FileMode.Append:
                     break;
                 default:
                     break;
@@ -575,8 +574,8 @@ class MyClass
         void Method()
         {
             var e = Append;
-            switch (e)
-            {[||]
+            switch ([|e|])
+            {
             }
         }
     }
@@ -593,17 +592,17 @@ void Method()
             var e = Append;
             switch (e)
             {
-                case CreateNew:
+                case System.IO.FileMode.CreateNew:
                     break;
-                case Create:
+                case System.IO.FileMode.Create:
                     break;
-                case Open:
+                case System.IO.FileMode.Open:
                     break;
-                case OpenOrCreate:
+                case System.IO.FileMode.OpenOrCreate:
                     break;
-                case Truncate:
+                case System.IO.FileMode.Truncate:
                     break;
-                case Append:
+                case System.IO.FileMode.Append:
                     break;
                 default:
                     break;
@@ -632,12 +631,12 @@ class MyClass
         void Method()
         {
             var e = MyEnum.Fizz;
-            switch (e)
+            switch ([|e|])
             {
-                [|case MyEnum.Fizz:
+                case MyEnum.Fizz:
                 case MyEnum.Buzz:
                 default:
-                    break;|]
+                    break;
             }
         }
     }
@@ -663,12 +662,12 @@ class MyClass
         void Method()
         {
             var e = MyEnum.Fizz;
-            switch (e)
+            switch ([|e|])
             {
-                [|case MyEnum.Fizz:
+                case MyEnum.Fizz:
                 case MyEnum.Buzz:
                 default:
-                    break;|]
+                    break;
             }
         }
     }
@@ -693,12 +692,12 @@ class MyClass
         void Method()
         {
             var e = MyEnum.Fizz;
-            switch (e)
+            switch ([|e|])
             {
-                [|case MyEnum.Fizz:
+                case MyEnum.Fizz:
                 case MyEnum.Buzz:
                 default:
-                    break;|]
+                    break;
             }
         }
     }
@@ -723,12 +722,12 @@ class MyClass
         void Method()
         {
             var e = MyEnum.Fizz;
-            switch (e)
+            switch ([|e|])
             {
-                [|case MyEnum.Fizz:
+                case MyEnum.Fizz:
                 case MyEnum.Buzz:
                 default:
-                    break;|]
+                    break;
             }
         }
     }
@@ -753,11 +752,11 @@ class MyClass
         void Method()
         {
             var e = MyEnum.Fizz;
-            switch (e)
+            switch ([|e|])
             {
-                [|case MyEnum.Fizz:
+                case MyEnum.Fizz:
                 case MyEnum.Buzz:
-                    break;|]
+                    break;
             }
         }
     }
@@ -809,11 +808,11 @@ enum MyEnum
         void Method()
         {
             var e = MyEnum.Fizz;
-            switch (e)
+            switch ([|e|])
             {
-                [|case MyEnum.Fizz:
+                case MyEnum.Fizz:
                 case MyEnum.Buzz:
-                    break;|]
+                    break;
             }
         }
     }
@@ -861,12 +860,12 @@ class MyClass
         void Method()
         {
             var e = ""test"";
-            switch (e)
+            switch ([|e|])
             {
-                [|case ""test1"":
+                case ""test1"":
                 case ""test1"":
                 default:
-                    break;|]
+                    break;
             }
         }
     }

src/EditorFeatures/CSharpTest/Diagnostics/PopulateSwitch/PopulateSwitchTests_FixAllTests.cs → src/EditorFeatures/CSharpTest/PopulateSwitch/PopulateSwitchTests_FixAllTests.cs

@@ -26,12 +26,12 @@ class MyClass1
         void Method()
         {
             var e = MyEnum.Fizz;
-            switch (e)
+            switch ({|FixAllInDocument:e|})
             {
-                {|FixAllInDocument:case MyEnum.Fizz:
+                case MyEnum.Fizz:
                 case MyEnum.Buzz:
                 case MyEnum.FizzBuzz:
-                    break;|}
+                    break;
             }
             switch (e)
             {
@@ -190,12 +190,12 @@ class MyClass1
         void Method()
         {
             var e = MyEnum.Fizz;
-            switch (e)
+            switch ({|FixAllInProject:e|})
             {
-                {|FixAllInProject:case MyEnum.Fizz:
+                case MyEnum.Fizz:
                 case MyEnum.Buzz:
                 case MyEnum.FizzBuzz:
-                    break;|}
+                    break;
             }
         }
     }
@@ -340,12 +340,12 @@ class MyClass1
         void Method()
         {
             var e = MyEnum1.Fizz;
-            switch (e)
+            switch ({|FixAllInSolution:e|})
             {
-                {|FixAllInSolution:case MyEnum1.Fizz:
+                case MyEnum1.Fizz:
                 case MyEnum1.Buzz:
                 case MyEnum1.FizzBuzz:
-                    break;|}
+                    break;
             }
         }
     }

src/EditorFeatures/VisualBasicTest/BasicEditorServicesTest.vbproj

@@ -202,8 +202,8 @@
     <Compile Include="Diagnostics\MakeMethodSynchronous\MakeMethodSynchronousTests.vb" />
     <Compile Include="Diagnostics\MoveToTopOfFile\MoveToTopOfFileTests.vb" />
     <Compile Include="Diagnostics\OverloadBase\OverloadBaseTests.vb" />
-    <Compile Include="Diagnostics\PopulateSwitch\PopulateSwitchTests.vb" />
-    <Compile Include="Diagnostics\PopulateSwitch\PopulateSwitchTests_FixAllTests.vb" />
+    <Compile Include="PopulateSwitch\PopulateSwitchTests.vb" />
+    <Compile Include="PopulateSwitch\PopulateSwitchTests_FixAllTests.vb" />
     <Compile Include="Diagnostics\RemoveUnnecessaryCast\RemoveUnnecessaryCastTests.vb" />
     <Compile Include="Diagnostics\RemoveUnnecessaryCast\RemoveUnnecessaryCastTests_FixAllTests.vb" />
     <Compile Include="Diagnostics\RemoveUnnecessaryImports\RemoveUnnecessaryImportsTests.vb" />

src/EditorFeatures/VisualBasicTest/Diagnostics/PopulateSwitch/PopulateSwitchTests.vb → src/EditorFeatures/VisualBasicTest/PopulateSwitch/PopulateSwitchTests.vb

@@ -8,7 +8,7 @@ Namespace Microsoft.CodeAnalysis.Editor.VisualBasic.UnitTests.Diagnostics.Popula
         Inherits AbstractVisualBasicDiagnosticProviderBasedUserDiagnosticTest
 
         Friend Overrides Function CreateDiagnosticProviderAndFixer(workspace As Workspace) As Tuple(Of DiagnosticAnalyzer, CodeFixProvider)
-            Return New Tuple(Of DiagnosticAnalyzer, CodeFixProvider)(New VisualBasicPopulateSwitchDiagnosticAnalyzer(), New PopulateSwitchCodeFixProvider())
+            Return New Tuple(Of DiagnosticAnalyzer, CodeFixProvider)(New VisualBasicPopulateSwitchDiagnosticAnalyzer(), New VisualBasicPopulateSwitchCodeFixProvider())
         End Function
 
         <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsPopulateSwitch)>
@@ -23,15 +23,15 @@ End Enum
 Class Foo
     Sub Bar()
         Dim e = MyEnum.Fizz
-        Select Case e
-            [|Case MyEnum.Fizz
+        Select Case [|e|]
+            Case MyEnum.Fizz
                 Exit Select
             Case MyEnum.Buzz
                 Exit Select
             Case MyEnum.FizzBuzz
                 Exit Select
             Case Else
-                Exit Select|]
+                Exit Select
         End Select
     End Sub
 End Class
@@ -39,7 +39,7 @@ End Class
 
             Await TestMissingAsync(markup)
         End Function
-        
+
         <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsPopulateSwitch)>
         Public Async Function AllMembersExist_NotElse() As Task
             Dim markup =
@@ -52,13 +52,13 @@ End Enum
 Class Foo
     Sub Bar()
         Dim e = MyEnum.Fizz
-        Select Case e
-            [|Case MyEnum.Fizz
+        Select Case [|e|]
+            Case MyEnum.Fizz
                 Exit Select
             Case MyEnum.Buzz
                 Exit Select
             Case MyEnum.FizzBuzz
-                Exit Select|]
+                Exit Select
         End Select
     End Sub
 End Class
@@ -90,7 +90,7 @@ End Class
 
             Await TestAsync(markup, expected, compareTokens:=False)
         End Function
-        
+
         <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsPopulateSwitch)>
         Public Async Function NotAllMembersExist_NotElse() As Task
             Dim markup =
@@ -103,11 +103,11 @@ End Enum
 Class Foo
     Sub Bar()
         Dim e = MyEnum.Fizz
-        Select Case e
-            [|Case MyEnum.Fizz
+        Select Case [|e|]
+            Case MyEnum.Fizz
                 Exit Select
             Case MyEnum.Buzz
-                Exit Select|]
+                Exit Select
         End Select
     End Sub
 End Class
@@ -139,7 +139,7 @@ End Class
 
             Await TestAsync(markup, expected, compareTokens:=False)
         End Function
-        
+
         <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsPopulateSwitch)>
         Public Async Function NotAllMembersExist_WithElse() As Task
             Dim markup =
@@ -152,13 +152,13 @@ End Enum
 Class Foo
     Sub Bar()
         Dim e = MyEnum.Fizz
-        Select Case e
-            [|Case MyEnum.Fizz
+        Select Case [|e|]
+            Case MyEnum.Fizz
                 Exit Select
             Case MyEnum.Buzz
                 Exit Select
             Case Else
-                Exit Select|]
+                Exit Select
         End Select
     End Sub
 End Class
@@ -190,7 +190,7 @@ End Class
 
             Await TestAsync(markup, expected, compareTokens:=False)
         End Function
-        
+
         <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsPopulateSwitch)>
         Public Async Function NotAllMembersExist_NotElse_EnumHasExplicitType() As Task
             Dim markup =
@@ -203,11 +203,11 @@ End Enum
 Class Foo
     Sub Bar()
         Dim e = MyEnum.Fizz
-        Select Case e
-            [|Case MyEnum.Fizz
+        Select Case [|e|]
+            Case MyEnum.Fizz
                 Exit Select
             Case MyEnum.Buzz
-                Exit Select|]
+                Exit Select
         End Select
     End Sub
 End Class
@@ -239,7 +239,7 @@ End Class
 
             Await TestAsync(markup, expected, compareTokens:=False)
         End Function
-        
+
         <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsPopulateSwitch)>
         Public Async Function NotAllMembersExist_WithMembersAndElseInBlock_NewValuesAboveElseBlock() As Task
             Dim markup =
@@ -252,12 +252,12 @@ End Enum
 Class Foo
     Sub Bar()
         Dim e = MyEnum.Fizz
-        Select Case e
-            [|Case MyEnum.Fizz
+        Select Case [|e|]
+            Case MyEnum.Fizz
                 Exit Select
             Case MyEnum.Buzz
             Case Else
-                Exit Select|]
+                Exit Select
         End Select
     End Sub
 End Class
@@ -301,7 +301,7 @@ End Enum
 Class Foo
     Sub Bar()
         Dim e = MyEnum.Fizz
-        Select Case e[||]
+        Select Case [|e|]
         End Select
     End Sub
 End Class
@@ -330,7 +330,7 @@ Class Foo
     End Sub
 End Class
 </File>
-            
+
             Await TestAsync(markup, expected, compareTokens:=False)
         End Function
 
@@ -347,8 +347,8 @@ End Enum
 Class Foo
     Sub Bar()
         Dim e = CreateNew
-        Select Case e
-            [|Case CreateNew
+        Select Case [|e|]
+            Case CreateNew
                 Exit Select
             Case Create
                 Exit Select
@@ -361,12 +361,12 @@ Class Foo
             Case Append
                 Exit Select
             Case Else
-                Exit Select|]
+                Exit Select
         End Select
     End Sub
 End Class
 </File>
-            
+
             Await TestMissingAsync(markup)
         End Function
 
@@ -383,8 +383,8 @@ End Enum
 Class Foo
     Sub Bar()
         Dim e = CreateNew
-        Select Case e
-            [|Case Truncate
+        Select Case [|e|]
+            Case Truncate
                 Exit Select
             Case Append
                 Exit Select
@@ -397,12 +397,12 @@ Class Foo
             Case Create
                 Exit Select
             Case Else
-                Exit Select|]
+                Exit Select
         End Select
     End Sub
 End Class
 </File>
-            
+
             Await TestMissingAsync(markup)
         End Function
 
@@ -419,21 +419,21 @@ End Enum
 Class Foo
     Sub Bar()
         Dim e = CreateNew
-        Select Case e
-            [|Case CreateNew
+        Select Case [|e|]
+            Case CreateNew
                 Exit Select
             Case Create
                 Exit Select
             Case Open
                 Exit Select
             Case Else
-                Exit Select|]
+                Exit Select
         End Select
     End Sub
 End Class
 </File>
 
-                        Dim expected =
+            Dim expected =
 <File>
 Imports System.IO.FileMode
 Enum MyEnum
@@ -451,11 +451,11 @@ Class Foo
                 Exit Select
             Case Open
                 Exit Select
-            Case System.IO.FileMode.Append
+            Case System.IO.FileMode.OpenOrCreate
                 Exit Select
             Case System.IO.FileMode.Truncate
                 Exit Select
-            Case System.IO.FileMode.OpenOrCreate
+            Case System.IO.FileMode.Append
                 Exit Select
             Case Else
                 Exit Select
@@ -463,7 +463,7 @@ Class Foo
     End Sub
 End Class
 </File>
-            
+
             Await TestAsync(markup, expected, compareTokens:=False)
         End Function
 
@@ -480,14 +480,14 @@ End Enum
 Class Foo
     Sub Bar()
         Dim e = CreateNew
-        Select Case e
-            [||]
+        Select Case [|e|]
+            
         End Select
     End Sub
 End Class
 </File>
 
-                        Dim expected =
+            Dim expected =
 <File>
 Imports System.IO.FileMode
 Enum MyEnum
@@ -517,10 +517,10 @@ Class Foo
     End Sub
 End Class
 </File>
-            
+
             Await TestAsync(markup, expected, compareTokens:=False)
         End Function
-        
+
         <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsPopulateSwitch)>
         Public Async Function NotAllMembersExist_EnumIsFlags() As Task
             Dim markup =
@@ -535,11 +535,11 @@ End Enum
 Class Foo
     Sub Bar()
         Dim e = MyEnum.Fizz
-        Select Case e
-            [|Case MyEnum.Fizz
+        Select Case [|e|]
+            Case MyEnum.Fizz
                 Exit Select
             Case MyEnum.Buzz
-                Exit Select|]
+                Exit Select
         End Select
     End Sub
 End Class
@@ -547,7 +547,7 @@ End Class
 
             Await TestMissingAsync(markup)
         End Function
-        
+
         <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsPopulateSwitch)>
         Public Async Function NotAllMembersExist_EnumIsFlagsAttribute() As Task
             Dim markup =
@@ -562,11 +562,11 @@ End Enum
 Class Foo
     Sub Bar()
         Dim e = MyEnum.Fizz
-        Select Case e
-            [|Case MyEnum.Fizz
+        Select Case [|e|]
+            Case MyEnum.Fizz
                 Exit Select
             Case MyEnum.Buzz
-                Exit Select|]
+                Exit Select
         End Select
     End Sub
 End Class
@@ -574,7 +574,7 @@ End Class
 
             Await TestMissingAsync(markup)
         End Function
-        
+
         <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsPopulateSwitch)>
         Public Async Function NotAllMembersExist_EnumIsFullyQualifiedSystemFlags() As Task
             Dim markup =
@@ -588,11 +588,11 @@ End Enum
 Class Foo
     Sub Bar()
         Dim e = MyEnum.Fizz
-        Select Case e
-            [|Case MyEnum.Fizz
+        Select Case [|e|]
+            Case MyEnum.Fizz
                 Exit Select
             Case MyEnum.Buzz
-                Exit Select|]
+                Exit Select
         End Select
     End Sub
 End Class
@@ -600,7 +600,7 @@ End Class
 
             Await TestMissingAsync(markup)
         End Function
-        
+
         <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsPopulateSwitch)>
         Public Async Function NotAllMembersExist_EnumIsFullyQualifiedSystemFlagsAttribute() As Task
             Dim markup =
@@ -614,11 +614,11 @@ End Enum
 Class Foo
     Sub Bar()
         Dim e = MyEnum.Fizz
-        Select Case e
-            [|Case MyEnum.Fizz
+        Select Case [|e|]
+            Case MyEnum.Fizz
                 Exit Select
             Case MyEnum.Buzz
-                Exit Select|]
+                Exit Select
         End Select
     End Sub
 End Class
@@ -626,7 +626,7 @@ End Class
 
             Await TestMissingAsync(markup)
         End Function
-        
+
         <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsPopulateSwitch)>
         Public Async Function NotAllMembersExist_EnumHasNonFlagsAttribute() As Task
             Dim markup =
@@ -640,11 +640,11 @@ End Enum
 Class Foo
     Sub Bar()
         Dim e = MyEnum.Fizz
-        Select Case e
-            [|Case MyEnum.Fizz
+        Select Case [|e|]
+            Case MyEnum.Fizz
                 Exit Select
             Case MyEnum.Buzz
-                Exit Select|]
+                Exit Select
         End Select
     End Sub
 End Class
@@ -677,7 +677,7 @@ End Class
 
             Await TestAsync(markup, expected, compareTokens:=False)
         End Function
-        
+
         <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsPopulateSwitch)>
         Public Async Function NotAllMembersExist_EnumIsNested() As Task
             Dim markup =
@@ -690,11 +690,11 @@ Class Foo
     End Enum
     Sub Bar()
         Dim e = MyEnum.Fizz
-        Select Case e
-            [|Case MyEnum.Fizz
+        Select Case [|e|]
+            Case MyEnum.Fizz
                 Exit Select
             Case MyEnum.Buzz
-                Exit Select|]
+                Exit Select
         End Select
     End Sub
 End Class
@@ -715,7 +715,7 @@ Class Foo
                 Exit Select
             Case MyEnum.Buzz
                 Exit Select
-            Case Foo.MyEnum.FizzBuzz
+            Case MyEnum.FizzBuzz
                 Exit Select
             Case Else
                 Exit Select
@@ -726,7 +726,7 @@ End Class
 
             Await TestAsync(markup, expected, compareTokens:=False)
         End Function
-        
+
         <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsPopulateSwitch)>
         Public Async Function NotAllMembersExist_SwitchIsNotEnum() As Task
             Dim markup =
@@ -734,11 +734,11 @@ End Class
 Class Foo
     Sub Bar()
         Dim e = "Test"
-        Select Case e
-            [|Case "Fizz"
+        Select Case [|e|]
+            Case "Fizz"
                 Exit Select
             Case Test"
-                Exit Select|]
+                Exit Select
         End Select
     End Sub
 End Class

src/EditorFeatures/VisualBasicTest/Diagnostics/PopulateSwitch/PopulateSwitchTests_FixAllTests.vb → src/EditorFeatures/VisualBasicTest/PopulateSwitch/PopulateSwitchTests_FixAllTests.vb

@@ -17,13 +17,13 @@ End Enum
 Class Foo
     Sub Bar()
         Dim e = MyEnum1.Fizz
-        Select Case e
-            {|FixAllInDocument:Case MyEnum1.Fizz
+        Select Case {|FixAllInDocument:e|}
+            Case MyEnum1.Fizz
                 Exit Select
             Case MyEnum1.Buzz
                 Exit Select
             Case Else
-                Exit Select|}
+                Exit Select
         End Select
 
         Select Case e
@@ -163,7 +163,7 @@ End Class]]>
                                    </Document>
                                </Project>
                            </Workspace>.ToString()
-            
+
             Await TestAsync(input, expected, compareTokens:=False, fixAllActionEquivalenceKey:=Nothing)
         End Function
 
@@ -182,13 +182,13 @@ End Enum
 Class Foo
     Sub Bar()
         Dim e = MyEnum1.Fizz
-        Select Case e
-            {|FixAllInProject:Case MyEnum1.Fizz
+        Select Case {|FixAllInProject:e|}
+            Case MyEnum1.Fizz
                 Exit Select
             Case MyEnum1.Buzz
                 Exit Select
             Case MyEnum1.FizzBuzz
-                Exit Select|}
+                Exit Select
         End Select
     End Sub
 End Class]]>
@@ -310,7 +310,7 @@ End Class]]>
                                    </Document>
                                </Project>
                            </Workspace>.ToString()
-            
+
             Await TestAsync(input, expected, compareTokens:=False, fixAllActionEquivalenceKey:=Nothing)
         End Function
 
@@ -329,11 +329,11 @@ End Enum
 Class Foo
     Sub Bar()
         Dim e = MyEnum1.Fizz
-        Select Case e
-            {|FixAllInSolution:Case MyEnum1.Fizz
+        Select Case {|FixAllInSolution:e|}
+            Case MyEnum1.Fizz
                 Exit Select
             Case MyEnum1.Buzz
-                Exit Select|}
+                Exit Select
         End Select
     End Sub
 End Class]]>
@@ -453,7 +453,7 @@ End Class]]>
                                    </Document>
                                </Project>
                            </Workspace>.ToString()
-            
+
             Await TestAsync(input, expected, compareTokens:=False, fixAllActionEquivalenceKey:=Nothing)
         End Function
     End Class

src/Features/CSharp/Portable/CSharpFeatures.csproj

@@ -80,8 +80,6 @@
     <Compile Include="CodeFixes\ImplementInterface\ImplementInterfaceCodeFixProvider.cs" />
     <Compile Include="CodeFixes\Iterator\CSharpAddYieldCodeFixProvider.cs" />
     <Compile Include="CodeFixes\Iterator\CSharpChangeToIEnumerableCodeFixProvider.cs" />
-    <Compile Include="CodeFixes\PopulateSwitch\PopulateSwitchCodeFixProvider.cs" />
-    <Compile Include="CodeFixes\PopulateSwitch\PopulateSwitchCodeFixProvider.PopulateSwitchFixAllProvider.cs" />
     <Compile Include="CodeFixes\RemoveUnnecessaryCast\RemoveUnnecessaryCastCodeFixProvider.RemoveUnnecessaryCastFixAllProvider.cs" />
     <Compile Include="CodeFixes\RemoveUnnecessaryCast\RemoveUnnecessaryCastCodeFixProvider.cs" />
     <Compile Include="CodeFixes\RemoveUnnecessaryUsings\RemoveUnnecessaryUsingsCodeFixProvider.cs" />
@@ -267,7 +265,7 @@
       <DesignTime>True</DesignTime>
       <DependentUpon>CSharpFeaturesResources.resx</DependentUpon>
     </Compile>
-    <Compile Include="Diagnostics\Analyzers\CSharpPopulateSwitchDiagnosticAnalyzer.cs" />
+    <Compile Include="PopulateSwitch\CSharpPopulateSwitchDiagnosticAnalyzer.cs" />
     <Compile Include="Diagnostics\Analyzers\CSharpUnboundIdentifiersDiagnosticAnalyzer.cs" />
     <Compile Include="Diagnostics\Analyzers\CSharpRemoveUnnecessaryCastDiagnosticAnalyzer.cs" />
     <Compile Include="Diagnostics\Analyzers\CSharpRemoveUnnecessaryImportsDiagnosticAnalyzer.cs" />
@@ -352,6 +350,7 @@
     <Compile Include="Organizing\Organizers\OperatorDeclarationOrganizer.cs" />
     <Compile Include="Organizing\Organizers\PropertyDeclarationOrganizer.cs" />
     <Compile Include="Organizing\Organizers\StructDeclarationOrganizer.cs" />
+    <Compile Include="PopulateSwitch\CSharpPopulateSwitchCodeFixProvider.cs" />
     <Compile Include="RemoveUnnecessaryImports\CSharpRemoveUnnecessaryImportsService.cs" />
     <Compile Include="RemoveUnnecessaryImports\CSharpRemoveUnnecessaryImportsService.Rewriter.cs" />
     <Compile Include="ReplaceMethodWithProperty\CSharpReplaceMethodWithPropertyService.cs" />

src/Features/CSharp/Portable/CodeFixes/PopulateSwitch/PopulateSwitchCodeFixProvider.PopulateSwitchFixAllProvider.cs

-using System.Threading;
-using System.Threading.Tasks;
-using Microsoft.CodeAnalysis.CodeFixes;
-using Microsoft.CodeAnalysis.CSharp.Syntax;
-
-namespace Microsoft.CodeAnalysis.CSharp.CodeFixes.PopulateSwitch
-{
-    internal partial class PopulateSwitchCodeFixProvider : CodeFixProvider
-    {
-        private class PopulateSwitchFixAllProvider : BatchSimplificationFixAllProvider
-        {
-            internal static new readonly PopulateSwitchFixAllProvider Instance = new PopulateSwitchFixAllProvider();
-
-            protected override SyntaxNode GetNodeToSimplify(SyntaxNode root, SemanticModel model, Diagnostic diagnostic, Workspace workspace, out string codeActionId, CancellationToken cancellationToken)
-            {
-                codeActionId = null;
-                return GetSwitchStatementNode(root, diagnostic.Location.SourceSpan);
-            }
-
-            protected override bool NeedsParentFixup
-            {
-                get
-                {
-                    return true;
-                }
-            }
-
-            protected override async Task<Document> AddSimplifyAnnotationsAsync(Document document, SyntaxNode nodeToSimplify, CancellationToken cancellationToken)
-            {
-                var switchBlock = nodeToSimplify as SwitchStatementSyntax;
-                if (switchBlock == null)
-                {
-                    return null;
-                }
-
-                var root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
-                var model = await document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
-
-                return await AddMissingSwitchLabelsAsync(model, document, root, switchBlock).ConfigureAwait(false);
-            }
-        }
-    }
-}

src/Features/CSharp/Portable/CodeFixes/PopulateSwitch/PopulateSwitchCodeFixProvider.cs → src/Features/CSharp/Portable/PopulateSwitch/CSharpPopulateSwitchCodeFixProvider.cs

-using System;
-using System.Collections.Generic;
-using System.Collections.Immutable;
+using System.Collections.Generic;
 using System.Composition;
-using System.Threading;
-using System.Threading.Tasks;
-using Microsoft.CodeAnalysis.CodeActions;
 using Microsoft.CodeAnalysis.CodeFixes;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
-using Microsoft.CodeAnalysis.Diagnostics;
 using Microsoft.CodeAnalysis.Formatting;
 using Microsoft.CodeAnalysis.Simplification;
 using Microsoft.CodeAnalysis.Text;
 
 namespace Microsoft.CodeAnalysis.CSharp.CodeFixes.PopulateSwitch
 {
-    [ExportCodeFixProvider(LanguageNames.CSharp, Name = PredefinedCodeFixProviderNames.AddLabelsToSwitch), Shared]
+    [ExportCodeFixProvider(LanguageNames.CSharp, Name = PredefinedCodeFixProviderNames.PopulateSwitch), Shared]
     [ExtensionOrder(After = PredefinedCodeFixProviderNames.ImplementInterface)]
-    internal partial class PopulateSwitchCodeFixProvider : CodeFixProvider
+    internal class CSharpPopulateSwitchCodeFixProvider : AbstractPopulateSwitchCodeFixProvider
     {
-        public override ImmutableArray<string> FixableDiagnosticIds
-        {
-            get { return ImmutableArray.Create(IDEDiagnosticIds.PopulateSwitchDiagnosticId); }
-        }
-
-        public sealed override FixAllProvider GetFixAllProvider()
-        {
-            return PopulateSwitchFixAllProvider.Instance;
-        }
-
-        private static SwitchStatementSyntax GetSwitchStatementNode(SyntaxNode root, TextSpan span)
+        protected override SyntaxNode GetSwitchStatementNode(SyntaxNode root, TextSpan span)
         {
             var token = root.FindToken(span.Start);
             if (!token.Span.IntersectsWith(span))
             {
                 return null;
             }
-
-            return (SwitchStatementSyntax)root.FindNode(span);
+            
+            var switchExpression = (ExpressionSyntax)root.FindNode(span);
+            return (SwitchStatementSyntax) switchExpression.Parent;
         }
 
-        public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
+        protected override SyntaxNode GetSwitchExpression(SyntaxNode node)
         {
-            var document = context.Document;
-            var span = context.Span;
-            var cancellationToken = context.CancellationToken;
-
-            var root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
-            var model = await document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
-            var node = GetSwitchStatementNode(root, span);
-            if (node == null)
-            {
-                return;
-            }
-
-            context.RegisterCodeFix(
-                new MyCodeAction(
-                    CSharpFeaturesResources.AddSwitchLabels,
-                    (c) => AddMissingSwitchLabelsAsync(model, document, root, node)),
-                context.Diagnostics);
+            var switchStatement = (SwitchStatementSyntax)node;
+            return switchStatement.Expression;
         }
 
-        private static async Task<Document> AddMissingSwitchLabelsAsync(SemanticModel model, Document document, SyntaxNode root, SwitchStatementSyntax switchBlock)
+        protected override List<string> GetMissingLabels(SyntaxNode node, SemanticModel model, INamedTypeSymbol enumType, out bool containsDefaultLabel)
         {
-            var enumType = (INamedTypeSymbol)model.GetTypeInfo(switchBlock.Expression).Type;
-            var fullyQualifiedEnumType = enumType.ToDisplayString();
-
-            var containsDefaultLabel = false;
-
-            var caseLabels = new List<ExpressionSyntax>();
-            foreach (var section in switchBlock.Sections)
-            {
-                foreach (var label in section.Labels)
-                {
-                    var caseLabel = label as CaseSwitchLabelSyntax;
-                    if (caseLabel != null)
-                    {
-                        caseLabels.Add(caseLabel.Value);
-                        continue;
-                    }
-
-                    if (label.IsKind(SyntaxKind.DefaultSwitchLabel))
-                    {
-                        containsDefaultLabel = true;
-                    }
-                }
-            }
-
-            var missingLabels = GetMissingLabels(model, caseLabels, enumType);
-
-            var breakStatement = SyntaxFactory.BreakStatement();
-            var statements = SyntaxFactory.List(new List<StatementSyntax> { breakStatement });
-
-            var newSections = SyntaxFactory.List(switchBlock.Sections);
-            foreach (var label in missingLabels)
-            {
-                // If an existing simplified label exists, it means we can assume that works already and do it ourselves as well (ergo: there is a static using)
-                var caseLabel =
-                    SyntaxFactory.CaseSwitchLabel(
-                        SyntaxFactory.ParseExpression($"{fullyQualifiedEnumType}.{label}")
-                                     .WithTrailingTrivia(SyntaxFactory.ParseTrailingTrivia(Environment.NewLine)));
-
-                var section =
-                    SyntaxFactory.SwitchSection(SyntaxFactory.List(new List<SwitchLabelSyntax> { caseLabel }), statements)
-                                 .WithAdditionalAnnotations(Formatter.Annotation);
-
-                // ensure that the new cases are above the last section if a default case exists, but below all other sections
-                if (containsDefaultLabel)
-                {
-                    // this will not give an index-out-of-bounds error because we know there is at least one case block
-                    newSections = newSections.Insert(switchBlock.Sections.Count - 1, section);
-                }
-                else
-                {
-                    newSections = newSections.Add(section);
-                }
-            }
-            
-            if (!containsDefaultLabel)
-            {
-                newSections = newSections.Add(SyntaxFactory.SwitchSection(SyntaxFactory.List(
-                        new List<SwitchLabelSyntax> { SyntaxFactory.DefaultSwitchLabel() }), statements));
-            }
-
-            var newNode = switchBlock.WithSections(newSections).WithAdditionalAnnotations(Formatter.Annotation, Simplifier.Annotation);
-
-            var newRoot = root.ReplaceNode(switchBlock, newNode);
-            return await Simplifier.ReduceAsync(document.WithSyntaxRoot(newRoot)).ConfigureAwait(false);
-        }
+            var caseLabels = GetCaseLabels((SwitchStatementSyntax)node, out containsDefaultLabel);
 
-        private static IEnumerable<string> GetMissingLabels(SemanticModel model, List<ExpressionSyntax> caseLabels, INamedTypeSymbol enumType)
-        {
             var symbols = new List<ISymbol>();
             foreach (var label in caseLabels)
             {
@@ -185,12 +89,47 @@ private static IEnumerable<string> GetMissingLabels(SemanticModel model, List<Ex
             return missingLabels;
         }
 
-        private class MyCodeAction : CodeAction.DocumentChangeAction
+        protected override int InsertPosition(List<SyntaxNode> sections)
+        {
+            return sections.Count - 1;
+        }
+
+        protected override List<SyntaxNode> GetSwitchSections(SyntaxNode node)
+        {
+            var switchBlock = (SwitchStatementSyntax)node;
+            return new List<SyntaxNode>(switchBlock.Sections);
+        }
+
+        protected override SyntaxNode NewSwitchNode(SyntaxNode node, List<SyntaxNode> sections)
+        {
+            var switchBlock = (SwitchStatementSyntax)node;
+            return switchBlock.WithSections(SyntaxFactory.List(sections))
+                .WithAdditionalAnnotations(Formatter.Annotation, Simplifier.Annotation);
+        }
+
+        private List<ExpressionSyntax> GetCaseLabels(SwitchStatementSyntax switchBlock, out bool containsDefaultLabel)
         {
-            public MyCodeAction(string title, Func<CancellationToken, Task<Document>> createChangedDocument) :
-                base(title, createChangedDocument)
+            containsDefaultLabel = false;
+
+            var caseLabels = new List<ExpressionSyntax>();
+            foreach (var section in switchBlock.Sections)
             {
+                foreach (var label in section.Labels)
+                {
+                    var caseLabel = label as CaseSwitchLabelSyntax;
+                    if (caseLabel != null)
+                    {
+                        caseLabels.Add(caseLabel.Value);
+                    }
+
+                    if (label.IsKind(SyntaxKind.DefaultSwitchLabel))
+                    {
+                        containsDefaultLabel = true;
+                    }
+                }
             }
+
+            return caseLabels;
         }
     }
 }

src/Features/CSharp/Portable/Diagnostics/Analyzers/CSharpPopulateSwitchDiagnosticAnalyzer.cs → src/Features/CSharp/Portable/PopulateSwitch/CSharpPopulateSwitchDiagnosticAnalyzer.cs

-using System.Collections.Immutable;
-using System.Threading;
-using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.Diagnostics;
 using Microsoft.CodeAnalysis.Diagnostics.PopulateSwitch;
-using Microsoft.CodeAnalysis.Text;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 
 namespace Microsoft.CodeAnalysis.CSharp.Diagnostics.PopulateSwitch
 {
     [DiagnosticAnalyzer(LanguageNames.CSharp)]
-    internal sealed class CSharpPopulateSwitchDiagnosticAnalyzer : PopulateSwitchDiagnosticAnalyzerBase<SyntaxKind>
+    internal sealed class CSharpPopulateSwitchDiagnosticAnalyzer : AbstractPopulateSwitchDiagnosticAnalyzerBase<SyntaxKind>
     {
         private static readonly ImmutableArray<SyntaxKind> s_kindsOfInterest = ImmutableArray.Create(SyntaxKind.SwitchStatement);
+        protected override ImmutableArray<SyntaxKind> SyntaxKindsOfInterest { get; } = s_kindsOfInterest;
 
-        public override ImmutableArray<SyntaxKind> SyntaxKindsOfInterest
+        protected override SyntaxNode GetExpression(SyntaxNode node)
         {
-            get
-            {
-                return s_kindsOfInterest;
-            }
+            var switchBlock = (SwitchStatementSyntax)node;
+            return switchBlock.Expression;
         }
 
-        protected override TextSpan GetDiagnosticSpan(SyntaxNode node)
+        protected override List<SyntaxNode> GetCaseLabels(SyntaxNode node, out bool hasDefaultCase)
         {
-            var switchStatement = (SwitchStatementSyntax)node;
-            return switchStatement.Span;
-        }
+            hasDefaultCase = false;
 
-        protected override bool SwitchIsFullyPopulated(SemanticModel model, SyntaxNode node, CancellationToken cancellationToken)
-        {
             var switchBlock = (SwitchStatementSyntax)node;
-
-            var enumType = model.GetTypeInfo(switchBlock.Expression).Type as INamedTypeSymbol;
-            if (enumType == null || enumType.TypeKind != TypeKind.Enum)
-            {
-                return true;
-            }
-
-            // ignore enums marked with Flags per spec: https://github.com/dotnet/roslyn/issues/6766#issuecomment-156878851
-            foreach (var attribute in enumType.GetAttributes())
-            {
-                var containingClass = attribute.AttributeClass.ToDisplayString();
-                if (containingClass == typeof(System.FlagsAttribute).FullName)
-                {
-                    return true;
-                }
-            }
-
-            var caseLabels = new List<ExpressionSyntax>();
-            var hasDefaultCase = false;
+            var caseLabels = new List<SyntaxNode>();
 
             foreach (var section in switchBlock.Sections)
             {
@@ -66,42 +41,7 @@ protected override bool SwitchIsFullyPopulated(SemanticModel model, SyntaxNode n
                 }
             }
 
-            if (!hasDefaultCase)
-            {
-                return false;
-            }
-
-            var labelSymbols = new List<ISymbol>();
-            foreach (var label in caseLabels)
-            {
-                labelSymbols.Add(model.GetSymbolInfo(label).Symbol);
-            }
-
-            foreach (var member in enumType.GetMembers())
-            {
-                // skip `.ctor`
-                if (member.IsImplicitlyDeclared)
-                {
-                    continue;
-                }
-
-                var switchHasSymbol = false;
-                foreach (var symbol in labelSymbols)
-                {
-                    if (symbol == member)
-                    {
-                        switchHasSymbol = true;
-                        break;
-                    }
-                }
-
-                if (!switchHasSymbol)
-                {
-                    return false;
-                }
-            }
-
-            return true;
+            return caseLabels;
         }
     }
 }

src/Features/Core/Portable/CodeFixes/PredefinedCodeFixProviderNames.cs

@@ -6,7 +6,6 @@ internal static class PredefinedCodeFixProviderNames
     {
         public const string AddAwait = "Add Await For Expression";
         public const string AddAsync = "Add Async To Member";
-        public const string AddLabelsToSwitch = "Add Labels To Switch";
         public const string ChangeReturnType = "Change Return Type";
         public const string ChangeToYield = "Change To Yield";
         public const string ConvertToAsync = "Convert To Async";
@@ -29,6 +28,7 @@ internal static class PredefinedCodeFixProviderNames
         public const string ImplementInterface = "Implement Interface";
         public const string InsertMissingCast = nameof(InsertMissingCast);
         public const string MoveToTopOfFile = "Move To Top Of File";
+        public const string PopulateSwitch = "Populate Switch";
         public const string RemoveUnnecessaryCast = "Remove Unnecessary Casts";
         public const string RemoveUnnecessaryImports = "Remove Unnecessary Usings or Imports";
         public const string RenameTracking = "Rename Tracking";

src/Features/Core/Portable/Features.csproj

@@ -181,7 +181,7 @@
     <Compile Include="Completion\SuggestionMode\SuggestionModeCompletionProvider.cs" />
     <Compile Include="Diagnostics\AnalyzerHelper.cs" />
     <Compile Include="Diagnostics\AbstractHostDiagnosticUpdateSource.cs" />
-    <Compile Include="Diagnostics\Analyzers\PopulateSwitchDiagnosticAnalyzerBase.cs" />
+    <Compile Include="PopulateSwitch\AbstractPopulateSwitchDiagnosticAnalyzer.cs" />
     <Compile Include="Diagnostics\AnalyzerUpdateArgsId.cs" />
     <Compile Include="Diagnostics\DiagnosticEventTaskScheduler.cs" />
     <Compile Include="Diagnostics\DiagnosticService_UpdateSourceRegistrationService.cs" />
@@ -254,6 +254,7 @@
     <Compile Include="MakeMethodSynchronous\AbstractMakeMethodSynchronousCodeFixProvider.cs" />
     <Compile Include="Navigation\NavigationOptions.cs" />
     <Compile Include="Navigation\NavigationOptionsProvider.cs" />
+    <Compile Include="PopulateSwitch\AbstractPopulateSwitchCodeFixProvider.cs" />
     <Compile Include="QuickInfo\QuickInfoUtilities.cs" />
     <Compile Include="RemoveUnnecessaryImports\AbstractRemoveUnnecessaryImportsService.cs" />
     <Compile Include="ReplaceMethodWithProperty\ReplaceMethodWithPropertyCodeRefactoringProvider.cs" />

src/Features/Core/Portable/FeaturesResources.Designer.cs

@@ -241,6 +241,15 @@ internal class FeaturesResources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Add Missing Labels.
+        /// </summary>
+        internal static string AddSwitchLabels {
+            get {
+                return ResourceManager.GetString("AddSwitchLabels", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to An active statement has been removed from its original method. You must revert your changes to continue or restart the debugging session..
         /// </summary>

src/Features/Core/Portable/FeaturesResources.resx

@@ -916,4 +916,7 @@ This version used in: {2}</value>
   <data name="AddMissingStatements" xml:space="preserve">
     <value>Add missing statements to switch</value>
   </data>
+  <data name="AddSwitchLabels" xml:space="preserve">
+    <value>Add Missing Labels</value>
+  </data>
 </root>
\ No newline at end of file

src/Features/Core/Portable/PopulateSwitch/AbstractPopulateSwitchCodeFixProvider.cs

+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.CodeActions;
+using Microsoft.CodeAnalysis.CodeFixes;
+using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.Editing;
+using Microsoft.CodeAnalysis.Text;
+
+namespace Microsoft.CodeAnalysis.CSharp.CodeFixes.PopulateSwitch
+{
+    internal abstract class AbstractPopulateSwitchCodeFixProvider : CodeFixProvider
+    {
+        public override ImmutableArray<string> FixableDiagnosticIds => ImmutableArray.Create(IDEDiagnosticIds.PopulateSwitchDiagnosticId);
+
+        public override FixAllProvider GetFixAllProvider() => WellKnownFixAllProviders.BatchFixer;
+
+        public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
+        {
+            var document = context.Document;
+            var span = context.Span;
+            var cancellationToken = context.CancellationToken;
+
+            var root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
+            var model = await document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
+            var node = GetSwitchStatementNode(root, span);
+            if (node == null)
+            {
+                return;
+            }
+
+            context.RegisterCodeFix(
+                new MyCodeAction(
+                    FeaturesResources.AddSwitchLabels,
+                    c => AddMissingSwitchLabelsAsync(model, document, root, node)),
+                context.Diagnostics);
+        }
+
+        protected abstract SyntaxNode GetSwitchExpression(SyntaxNode node);
+
+        protected abstract List<string> GetMissingLabels(SyntaxNode node, SemanticModel model, INamedTypeSymbol enumType,
+            out bool containsDefaultLabel);
+
+        protected abstract int InsertPosition(List<SyntaxNode> sections);
+
+        protected abstract List<SyntaxNode> GetSwitchSections(SyntaxNode node);
+
+        protected abstract SyntaxNode NewSwitchNode(SyntaxNode node, List<SyntaxNode> sections);
+
+        protected abstract SyntaxNode GetSwitchStatementNode(SyntaxNode root, TextSpan span);
+
+        private Task<Document> AddMissingSwitchLabelsAsync(SemanticModel model, Document document, SyntaxNode root, SyntaxNode switchNode)
+        {
+            var enumType = (INamedTypeSymbol)model.GetTypeInfo(GetSwitchExpression(switchNode)).Type;
+            var fullyQualifiedEnumType = enumType.ToDisplayString();
+
+            bool containsDefaultLabel;
+            var missingLabels = GetMissingLabels(switchNode, model, enumType, out containsDefaultLabel);
+
+            var generator = SyntaxGenerator.GetGenerator(document);
+
+            var switchExitStatement = generator.ExitSwitchStatement();
+            var statements = new List<SyntaxNode> { switchExitStatement };
+
+            var newSections = GetSwitchSections(switchNode);
+            foreach (var label in missingLabels)
+            {
+                var caseLabel = generator.DottedName($"{fullyQualifiedEnumType}.{label}");
+
+                var section = generator.SwitchSection(caseLabel, new List<SyntaxNode> { switchExitStatement });
+
+                // ensure that the new cases are above the last section if a default case exists, but below all other sections
+                if (containsDefaultLabel)
+                {
+                    newSections.Insert(InsertPosition(newSections), section);
+                }
+                else
+                {
+                    newSections.Add(section);
+                }
+            }
+
+            if (!containsDefaultLabel)
+            {
+                newSections.Add(generator.DefaultSwitchSection(statements));
+            }
+
+            var newNode = NewSwitchNode(switchNode, newSections);
+
+            var newRoot = root.ReplaceNode(switchNode, newNode);
+            return Task.FromResult(document.WithSyntaxRoot(newRoot));
+        }
+
+        private class MyCodeAction : CodeAction.DocumentChangeAction
+        {
+            public MyCodeAction(string title, Func<CancellationToken, Task<Document>> createChangedDocument) :
+                base(title, createChangedDocument)
+            {
+            }
+        }
+    }
+}

src/Features/Core/Portable/Diagnostics/Analyzers/PopulateSwitchDiagnosticAnalyzerBase.cs → src/Features/Core/Portable/PopulateSwitch/AbstractPopulateSwitchDiagnosticAnalyzer.cs

 using Microsoft.CodeAnalysis.Shared.Extensions;
-using Microsoft.CodeAnalysis.Text;
+using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Threading;
 
 namespace Microsoft.CodeAnalysis.Diagnostics.PopulateSwitch
 {
-    internal abstract class PopulateSwitchDiagnosticAnalyzerBase<TLanguageKindEnum> : DiagnosticAnalyzer, IBuiltInAnalyzer where TLanguageKindEnum : struct
+    internal abstract class AbstractPopulateSwitchDiagnosticAnalyzerBase<TLanguageKindEnum> : DiagnosticAnalyzer, IBuiltInAnalyzer where TLanguageKindEnum : struct
     {
         private static readonly LocalizableString s_localizableTitle = new LocalizableResourceString(nameof(FeaturesResources.AddMissingStatements), FeaturesResources.ResourceManager, typeof(FeaturesResources));
         private static readonly LocalizableString s_localizableMessage = new LocalizableResourceString(nameof(WorkspacesResources.PopulateSwitch), WorkspacesResources.ResourceManager, typeof(WorkspacesResources));
@@ -14,24 +14,18 @@ internal abstract class PopulateSwitchDiagnosticAnalyzerBase<TLanguageKindEnum>
                                                                     s_localizableTitle,
                                                                     s_localizableMessage,
                                                                     DiagnosticCategory.EditAndContinue,
-                                                                    DiagnosticSeverity.Hidden,
+                                                                    DiagnosticSeverity.Warning,
                                                                     isEnabledByDefault: true,
                                                                     customTags: DiagnosticCustomTags.Unnecessary);
 
         #region Interface methods
 
-        public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics
-        {
-            get
-            {
-                return ImmutableArray.Create(s_descriptor);
-            }
-        }
+        public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create(s_descriptor);
 
         public override void Initialize(AnalysisContext context)
         {
             context.RegisterSyntaxNodeAction(
-                (nodeContext) =>
+                nodeContext =>
                 {
                     Diagnostic diagnostic;
                     if (TryPopulateSwitch(nodeContext.SemanticModel, nodeContext.Node, out diagnostic, nodeContext.CancellationToken))
@@ -42,24 +36,74 @@ public override void Initialize(AnalysisContext context)
                 SyntaxKindsOfInterest);
         }
 
-        public abstract ImmutableArray<TLanguageKindEnum> SyntaxKindsOfInterest { get; }
+        protected abstract ImmutableArray<TLanguageKindEnum> SyntaxKindsOfInterest { get; }
 
         #endregion
 
-        protected abstract bool SwitchIsFullyPopulated(SemanticModel model, SyntaxNode node, CancellationToken cancellationToken);
-        protected abstract TextSpan GetDiagnosticSpan(SyntaxNode node);
+        protected abstract SyntaxNode GetExpression(SyntaxNode node);
+        protected abstract List<SyntaxNode> GetCaseLabels(SyntaxNode node, out bool hasDefaultCase);
+
+        private bool SwitchIsFullyPopulated(SemanticModel model, SyntaxNode node)
+        {
+            var enumType = model.GetTypeInfo(GetExpression(node)).Type as INamedTypeSymbol;
+            if (enumType == null || enumType.TypeKind != TypeKind.Enum)
+            {
+                return true;
+            }
+
+            // ignore enums marked with Flags per spec: https://github.com/dotnet/roslyn/issues/6766#issuecomment-156878851
+            foreach (var attribute in enumType.GetAttributes())
+            {
+                var containingClass = attribute.AttributeClass.ToDisplayString();
+                if (containingClass == typeof(System.FlagsAttribute).FullName)
+                {
+                    return true;
+                }
+            }
+
+            bool hasDefaultCase;
+            var caseLabels = GetCaseLabels(node, out hasDefaultCase);
+
+            if (!hasDefaultCase)
+            {
+                return false;
+            }
+
+            var labelSymbols = new List<ISymbol>();
+            foreach (var label in caseLabels)
+            {
+                labelSymbols.Add(model.GetSymbolInfo(label).Symbol);
+            }
+
+            foreach (var member in enumType.GetMembers())
+            {
+                // skip `.ctor` and `__value`
+                var fieldSymbol = member as IFieldSymbol;
+                if (fieldSymbol == null || fieldSymbol.Type.SpecialType != SpecialType.None)
+                {
+                    continue;
+                }
+                
+                if (!labelSymbols.Contains(member))
+                {
+                    return false;
+                }
+            }
+
+            return true;
+        }
 
         private bool TryPopulateSwitch(SemanticModel model, SyntaxNode node, out Diagnostic diagnostic, CancellationToken cancellationToken)
         {
             diagnostic = default(Diagnostic);
 
-            if (SwitchIsFullyPopulated(model, node, cancellationToken))
+            if (SwitchIsFullyPopulated(model, node))
             {
                 return false;
             }
 
             var tree = model.SyntaxTree;
-            var span = GetDiagnosticSpan(node);
+            var span = GetExpression(node).Span;
             if (tree.OverlapsHiddenPosition(span, cancellationToken))
             {
                 return false;

src/Features/VisualBasic/Portable/BasicFeatures.vbproj

@@ -116,8 +116,7 @@
     <Compile Include="CodeFixes\MoveToTopOfFile\MoveToTopOfFileCodeFixProvider.vb" />
     <Compile Include="CodeFixes\OverloadBase\OverloadBaseCodeFixProvider.AddOverloads.vb" />
     <Compile Include="CodeFixes\OverloadBase\OverloadBaseCodeFixProvider.vb" />
-    <Compile Include="CodeFixes\PopulateSwitch\PopulateSwitchCodeFixProvider.PopulateSwitchCodeFixAllProvider.vb" />
-    <Compile Include="CodeFixes\PopulateSwitch\PopulateSwitchCodeFixProvider.vb" />
+    <Compile Include="PopulateSwitch\VisualBasicPopulateSwitchCodeFixProvider.vb" />
     <Compile Include="CodeFixes\RemoveUnnecessaryCast\RemoveUnnecessaryCastCodeFixProvider.RemoveUnnecessaryCastFixAllProvider.vb" />
     <Compile Include="CodeFixes\RemoveUnnecessaryCast\RemoveUnnecessaryCastCodeFixProvider.Rewriter.vb" />
     <Compile Include="CodeFixes\RemoveUnnecessaryCast\RemoveUnnecessaryCastCodeFixProvider.vb" />
@@ -304,7 +303,7 @@
     <Compile Include="Completion\KeywordRecommenders\Types\BuiltInTypesKeywordRecommender.vb" />
     <Compile Include="Completion\VisualBasicCompletionRules.vb" />
     <Compile Include="Completion\VisualBasicCompletionService.vb" />
-    <Compile Include="Diagnostics\Analyzers\VisualBasicPopulateSwitchDiagnosticAnalyzer.vb" />
+    <Compile Include="PopulateSwitch\VisualBasicPopulateSwitchDiagnosticAnalyzer.vb" />
     <Compile Include="Diagnostics\Analyzers\VisualBasicUnboundIdentifiersDiagnosticAnalyzer.vb" />
     <Compile Include="Diagnostics\Analyzers\VisualBasicRemoveUnnecessaryCastDiagnosticAnalyzer.vb" />
     <Compile Include="Diagnostics\Analyzers\VisualBasicRemoveUnnecessaryImportsDiagnosticAnalyzer.vb" />

src/Features/VisualBasic/Portable/CodeFixes/PopulateSwitch/PopulateSwitchCodeFixProvider.PopulateSwitchCodeFixAllProvider.vb

-Imports System.Threading
-Imports Microsoft.CodeAnalysis.CodeFixes
-Imports Microsoft.CodeAnalysis.VisualBasic.Syntax
-
-Namespace Microsoft.CodeAnalysis.VisualBasic.CodeFixes.PopulateSwitch
-    Partial Friend Class PopulateSwitchCodeFixProvider
-        Inherits CodeFixProvider
-		
-		Private Class PopulateSwitchCodeFixAllProvider
-            Inherits BatchSimplificationFixAllProvider
-			
-		    Friend Shared Shadows ReadOnly Instance As PopulateSwitchCodeFixAllProvider = New PopulateSwitchCodeFixAllProvider()
-
-            Protected Overrides Function GetNodeToSimplify(root As SyntaxNode, model As SemanticModel, diagnostic As Diagnostic, workspace As Workspace, ByRef codeActionId As String, cancellationToken As CancellationToken) As SyntaxNode
-                codeActionId = Nothing
-                Return GetSelectBlockNode(root, diagnostic.Location.SourceSpan)
-            End Function
-
-            Protected Overrides ReadOnly Property NeedsParentFixup As Boolean
-                Get
-                    Return True
-                End Get
-            End Property
-
-            Protected Overrides Async Function AddSimplifyAnnotationsAsync(document As Document, nodeToSimplify As SyntaxNode, cancellationToken As CancellationToken) As Task(Of Document)
-				
-				Dim selectBlock = TryCast(nodeToSimplify, SelectBlockSyntax)
-				If selectBlock Is Nothing
-					Return Nothing
-				End If
-
-				Dim root = Await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(False)
-				Dim model = Await document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(False)
-
-				Return Await AddMissingSwitchLabelsAsync(model, document, root, selectBlock).ConfigureAwait(False)
-            End Function
-        End Class
-    End Class
-End Namespace
\ No newline at end of file

src/Features/VisualBasic/Portable/CodeFixes/PopulateSwitch/PopulateSwitchCodeFixProvider.vb → src/Features/VisualBasic/Portable/PopulateSwitch/VisualBasicPopulateSwitchCodeFixProvider.vb

-Imports System.Collections.Immutable
-Imports System.Composition
-Imports System.Threading
-Imports Microsoft.CodeAnalysis.CodeActions
+Imports System.Composition
+Imports System.Runtime.InteropServices
 Imports Microsoft.CodeAnalysis.CodeFixes
-Imports Microsoft.CodeAnalysis.Diagnostics
+Imports Microsoft.CodeAnalysis.CSharp.CodeFixes.PopulateSwitch
 Imports Microsoft.CodeAnalysis.Formatting
 Imports Microsoft.CodeAnalysis.Simplification
 Imports Microsoft.CodeAnalysis.Text
 Imports Microsoft.CodeAnalysis.VisualBasic.Syntax
 
 Namespace Microsoft.CodeAnalysis.VisualBasic.CodeFixes.PopulateSwitch
-    <ExportCodeFixProvider(LanguageNames.VisualBasic, Name:=PredefinedCodeFixProviderNames.AddLabelsToSwitch), [Shared]>
+    <ExportCodeFixProvider(LanguageNames.VisualBasic, Name:=PredefinedCodeFixProviderNames.PopulateSwitch), [Shared]>
     <ExtensionOrder(After:=PredefinedCodeFixProviderNames.AddOverloads)>
-    Partial Friend Class PopulateSwitchCodeFixProvider
-        Inherits CodeFixProvider
+    Partial Friend Class VisualBasicPopulateSwitchCodeFixProvider
+        Inherits AbstractPopulateSwitchCodeFixProvider
 
-        Public NotOverridable Overrides ReadOnly Property FixableDiagnosticIds As ImmutableArray(Of String)
-            Get
-                Return ImmutableArray.Create(IDEDiagnosticIds.PopulateSwitchDiagnosticId)
-            End Get
-        End Property
+        Protected Overrides Function GetSwitchExpression(node As SyntaxNode) As SyntaxNode
 
-        Private Shared Function GetSelectBlockNode(root As SyntaxNode, span As TextSpan) As SelectBlockSyntax
-            Dim token = root.FindToken(span.Start)
-            If Not token.Span.IntersectsWith(span)
-                Return Nothing
-            End If
-
-            Return DirectCast(root.FindNode(span), SelectBlockSyntax)
-        End Function
-        
-        Public NotOverridable Overrides Async Function RegisterCodeFixesAsync(context As CodeFixContext) As Task
-            Dim document = context.Document
-            Dim span = context.Span
-            Dim cancellationToken = context.CancellationToken
-
-            Dim root = Await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(False)
-            Dim model = Await document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(False)
-
-            Dim node = GetSelectBlockNode(root, span)
-            If node Is Nothing Then
-                Return
-            End If
-
-            context.RegisterCodeFix(
-                New MyCodeAction(
-                    VBFeaturesResources.AddSelectLabels,
-                    Function(c) AddMissingSwitchLabelsAsync(model, document, root, node)),
-                context.Diagnostics)
-        End Function
-        
-        Private Shared Async Function AddMissingSwitchLabelsAsync(model As SemanticModel, document As Document, root As SyntaxNode, selectBlock As SelectBlockSyntax) As Task(Of Document)
-
-            Dim enumType = DirectCast(model.GetTypeInfo(selectBlock.SelectStatement.Expression).Type, INamedTypeSymbol)
-            Dim fullyQualifiedEnumType = enumType.ToDisplayString()
-
-            Dim containsElseCase = False
-
-            Dim caseLabels = New List(Of ExpressionSyntax)
-            For Each block In selectBlock.CaseBlocks
-                For Each caseSyntax In block.CaseStatement.Cases
-
-                    Dim simpleCaseClause = TryCast(caseSyntax, SimpleCaseClauseSyntax)
-                    If Not simpleCaseClause Is Nothing
-                        caseLabels.Add(simpleCaseClause.Value)
-                        Continue For
-                    End If
-
-                    If caseSyntax.IsKind(SyntaxKind.ElseCaseClause)
-                        containsElseCase = True
-                    End If
-                Next
-            Next
-            
-            Dim numOfBlocksWithNoStatementsWithElse = 0
-            If containsElseCase
-                ' skip the `Else` block
-                For i = selectBlock.CaseBlocks.Count - 2 To 0 Step -1
-                    If Not selectBlock.CaseBlocks.ElementAt(i).Statements.Count = 0
-
-                        ' insert the values immediately below the last item with statements
-                        numOfBlocksWithNoStatementsWithElse = i + 1
-                        Exit For
-                    End If
-                Next
-            End If
-
-            Dim missingLabels = GetMissingLabels(model, caseLabels, enumType)
-
-            Dim exitSelectStatement = SyntaxFactory.ExitSelectStatement()
-            Dim statements = SyntaxFactory.List(New List(Of StatementSyntax) From {exitSelectStatement})
-
-            Dim newSections = SyntaxFactory.List(selectBlock.CaseBlocks)
-            For Each label In missingLabels
-
-                Dim caseStatement = SyntaxFactory.CaseStatement(SyntaxFactory.SimpleCaseClause(SyntaxFactory.ParseExpression(fullyQualifiedEnumType + "." + label)))
-                Dim block = SyntaxFactory.CaseBlock(caseStatement, statements)
-                
-                ' ensure that the new cases are above the block with an else case, but below all other blocks
-                If containsElseCase
-                    ' this will not result in an InvalidOperationException because we know there
-                    ' are at least `numOfBlocksWithNoStatementsWithElse` items in the select block
-                    newSections = newSections.Insert(numOfBlocksWithNoStatementsWithElse, block)
-                Else
-                    newSections = newSections.Add(block)
-                End If
-            Next
-
-            If Not containsElseCase
-                newSections = newSections.Add(SyntaxFactory.CaseElseBlock(SyntaxFactory.CaseElseStatement(SyntaxFactory.ElseCaseClause()), statements))
-            End If
-
-            Dim newNode = selectBlock.WithCaseBlocks(newSections).WithAdditionalAnnotations(Formatter.Annotation, Simplifier.Annotation)
-            Dim newRoot = root.ReplaceNode(selectBlock, newNode)
-
-            ' This doesn't work, possibly because of https://github.com/dotnet/roslyn/issues/473
-            ' It creates `Namespace.EnumName.Member`, rather than `EnumName.Member`
-            ' Then, it immediately tells me that it can be simplified
-            Return Await Simplifier.ReduceAsync(document.WithSyntaxRoot(newRoot)).ConfigureAwait(False)
+            Dim selectBlock = DirectCast(node, SelectBlockSyntax)
+            Return selectBlock.SelectStatement.Expression
         End Function
 
-        Private Shared Function GetMissingLabels(model As SemanticModel, caseLabels As List(Of ExpressionSyntax), enumType As INamedTypeSymbol) As IEnumerable(Of String)
+        Protected Overrides Function GetMissingLabels(node As SyntaxNode, model As SemanticModel, enumType As INamedTypeSymbol, <Out> ByRef containsDefaultLabel As Boolean) As List(Of String)
 
+            Dim caseLabels = GetCaseLabels(DirectCast(node, SelectBlockSyntax), containsDefaultLabel)
             Dim symbols As New List(Of ISymbol)
 
             For Each label In caseLabels
-                
+
                 ' these are the labels like `MyEnum.EnumMember`
                 Dim memberAccessExpression = TryCast(label, MemberAccessExpressionSyntax)
                 If Not memberAccessExpression Is Nothing
@@ -136,7 +36,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.CodeFixes.PopulateSwitch
                         Continue For
                     End If
                 End If
-                
+
                 ' these are the labels like `EnumMember` (such as when using `Imports Namespace.MyEnum;`)
                 Dim identifierName = TryCast(label, IdentifierNameSyntax)
                 If Not identifierName Is Nothing
@@ -171,17 +71,67 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.CodeFixes.PopulateSwitch
 
             Return missingLabels
         End Function
-        
-        Public NotOverridable Overrides Function GetFixAllProvider() As FixAllProvider
-            Return PopulateSwitchCodeFixAllProvider.Instance
+
+        Protected Overrides Function InsertPosition(sections As List(Of SyntaxNode)) As Integer
+
+            Dim cases = sections.OfType(Of CaseBlockSyntax).ToList()
+            Dim numOfBlocksWithNoStatementsWithElse = 0
+
+            ' skip the `Else` block
+            For i = cases.Count - 2 To 0 Step -1
+                If Not cases.ElementAt(i).Statements.Count = 0
+
+                    ' insert the values immediately below the last item with statements
+                    numOfBlocksWithNoStatementsWithElse = i + 1
+                    Exit For
+                End If
+            Next
+
+            Return numOfBlocksWithNoStatementsWithElse
+        End Function
+
+        Protected Overrides Function GetSwitchSections(node As SyntaxNode) As List(Of SyntaxNode)
+
+            Dim selectBlock = DirectCast(node, SelectBlockSyntax)
+            Return New List(Of SyntaxNode)(selectBlock.CaseBlocks)
+        End Function
+
+        Protected Overrides Function NewSwitchNode(node As SyntaxNode, sections As List(Of SyntaxNode)) As SyntaxNode
+            Dim selectBlock = DirectCast(node, SelectBlockSyntax)
+            Return selectBlock.WithCaseBlocks(SyntaxFactory.List(sections)).WithAdditionalAnnotations(Formatter.Annotation, Simplifier.Annotation)
+        End Function
+
+        Protected Overrides Function GetSwitchStatementNode(root As SyntaxNode, span As TextSpan) As SyntaxNode
+            Dim token = root.FindToken(span.Start)
+            If Not token.Span.IntersectsWith(span)
+                Return Nothing
+            End If
+
+            Dim selectExpression = DirectCast(root.FindNode(span), ExpressionSyntax)
+            Return DirectCast(selectExpression.Parent.Parent, SelectBlockSyntax)
+        End Function
+
+        Private Function GetCaseLabels(selectBlock As SelectBlockSyntax, <Out> ByRef containsDefaultLabel As Boolean) As List(Of ExpressionSyntax)
+
+            containsDefaultLabel = False
+
+            Dim caseLabels = New List(Of ExpressionSyntax)
+            For Each block In selectBlock.CaseBlocks
+                For Each caseSyntax In block.CaseStatement.Cases
+
+                    Dim simpleCaseClause = TryCast(caseSyntax, SimpleCaseClauseSyntax)
+                    If Not simpleCaseClause Is Nothing
+                        caseLabels.Add(simpleCaseClause.Value)
+                        Continue For
+                    End If
+
+                    If caseSyntax.IsKind(SyntaxKind.ElseCaseClause)
+                        containsDefaultLabel = True
+                    End If
+                Next
+            Next
+
+            Return caseLabels
         End Function
-        
-        Private Class MyCodeAction
-            Inherits CodeAction.DocumentChangeAction
-
-            Public Sub New(title As String, createChangedDocument As Func(Of CancellationToken, Task(Of Document)))
-                MyBase.New(title, createChangedDocument)
-            End Sub
-        End Class
     End Class
 End Namespace
\ No newline at end of file

src/Features/VisualBasic/Portable/Diagnostics/Analyzers/VisualBasicPopulateSwitchDiagnosticAnalyzer.vb → src/Features/VisualBasic/Portable/PopulateSwitch/VisualBasicPopulateSwitchDiagnosticAnalyzer.vb

 Imports System.Collections.Immutable
-Imports System.Threading
+Imports System.Runtime.InteropServices
 Imports Microsoft.CodeAnalysis.Diagnostics
 Imports Microsoft.CodeAnalysis.Diagnostics.PopulateSwitch
-Imports Microsoft.CodeAnalysis.Text
 Imports Microsoft.CodeAnalysis.VisualBasic.Syntax
 
 Namespace Microsoft.CodeAnalysis.VisualBasic.Diagnostics.PopulateSwitch
 
     <DiagnosticAnalyzer(LanguageNames.VisualBasic)>
     Friend NotInheritable Class VisualBasicPopulateSwitchDiagnosticAnalyzer
-        Inherits PopulateSwitchDiagnosticAnalyzerBase(Of SyntaxKind)
+        Inherits AbstractPopulateSwitchDiagnosticAnalyzerBase(Of SyntaxKind)
 
-        Private Shared ReadOnly s_kindsOfInterest As ImmutableArray(Of SyntaxKind) = ImmutableArray.Create(SyntaxKind.SelectBlock)
-        Public Overrides ReadOnly Property SyntaxKindsOfInterest As ImmutableArray(Of SyntaxKind)
-            Get
-                Return s_kindsOfInterest
-            End Get
-        End Property
-
-        Protected Overrides Function GetDiagnosticSpan(node As SyntaxNode) As TextSpan
-            Return DirectCast(node, SelectBlockSyntax).Span
-        End Function
-
-        Protected Overrides Function SwitchIsFullyPopulated(model As SemanticModel, node As SyntaxNode, cancellationToken As CancellationToken) As Boolean
+        Protected Overrides Function GetCaseLabels(node As SyntaxNode, <Out> ByRef hasDefaultCase As Boolean) As List(Of SyntaxNode)
 
             Dim selectBlock = DirectCast(node, SelectBlockSyntax)
 
-            Dim enumType = TryCast(model.GetTypeInfo(selectBlock.SelectStatement.Expression).Type, INamedTypeSymbol)
-
-            If enumType Is Nothing OrElse Not enumType.TypeKind = TypeKind.Enum
-                Return True
-            End If
-
-            ' ignore enums marked with Flags per spec: https://github.com/dotnet/roslyn/issues/6766#issuecomment-156878851
-            For Each attribute In enumType.GetAttributes()
-
-                Dim containingClass = attribute.AttributeClass.ToDisplayString()
-                If containingClass = GetType(FlagsAttribute).FullName
-                    Return True
-                End If
-            Next
-
-            Dim caseLabels As New List(Of ExpressionSyntax)
-            Dim hasElseCase = False
+            Dim caseLabels As New List(Of SyntaxNode)
+            hasDefaultCase = False
 
             For Each block In selectBlock.CaseBlocks
                 For Each caseClause In block.CaseStatement.Cases
@@ -51,42 +24,21 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Diagnostics.PopulateSwitch
                     End If
 
                     If caseClause.IsKind(SyntaxKind.ElseCaseClause)
-                        hasElseCase = True
+                        hasDefaultCase = True
                     End If
                 Next
             Next
 
-            If Not hasElseCase
-                Return False
-            End If
-
-            Dim labelSymbols As New List(Of ISymbol)
-            For Each label In caseLabels
-                labelSymbols.Add(model.GetSymbolInfo(label).Symbol)
-            Next
-
-            For Each member In enumType.GetMembers()
-                ' skip `.ctor` and `value__`
-                ' member.IsImplicitlyDeclared doesn't work because `FileMode.value__` is apparently explicitly declared
-                Dim field = TryCast(member, IFieldSymbol)
-                If field Is Nothing OrElse (Not field.Type.SpecialType = SpecialType.None)
-                    Continue For
-                End If
+            Return caseLabels
+        End Function
 
-                Dim switchHasSymbol = False
-                For Each symbol In labelSymbols
-                    If symbol Is member
-                        switchHasSymbol = True
-                        Exit For
-                    End If
-                Next
+        Private Shared ReadOnly s_kindsOfInterest As ImmutableArray(Of SyntaxKind) = ImmutableArray.Create(SyntaxKind.SelectBlock)
+        Protected Overrides ReadOnly Property SyntaxKindsOfInterest As ImmutableArray(Of SyntaxKind) = s_kindsOfInterest
 
-                If Not switchHasSymbol
-                    Return False
-                End If
-            Next
+        Protected Overrides Function GetExpression(node As SyntaxNode) As SyntaxNode
 
-            Return True
+            Dim selectBlock = DirectCast(node, SelectBlockSyntax)
+            Return selectBlock.SelectStatement.Expression
         End Function
     End Class
 End Namespace

src/Workspaces/VisualBasic/Portable/CodeGeneration/VisualBasicSyntaxGenerator.vb

@@ -384,8 +384,8 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.CodeGeneration
         End Function
 
         Public Overrides Function DefaultSwitchSection(statements As IEnumerable(Of SyntaxNode)) As SyntaxNode
-            Return SyntaxFactory.CaseBlock(
-                SyntaxFactory.CaseStatement(SyntaxFactory.ElseCaseClause()),
+            Return SyntaxFactory.CaseElseBlock(
+                SyntaxFactory.CaseElseStatement(SyntaxFactory.ElseCaseClause()),
                 GetStatementList(statements))
         End Function