Use switch expression

src/VisualStudio/CSharp/Impl/CodeModel/CSharpCodeModelService.cs

@@ -1512,21 +1512,14 @@ public override MethodKind GetAccessorKind(SyntaxNode node)
             };
 
         private static SyntaxKind GetAccessorSyntaxKind(MethodKind methodKind)
-        {
-            switch (methodKind)
+            => methodKind switch
             {
-                case MethodKind.PropertyGet:
-                    return SyntaxKind.GetAccessorDeclaration;
-                case MethodKind.PropertySet:
-                    return SyntaxKind.SetAccessorDeclaration;
-                case MethodKind.EventAdd:
-                    return SyntaxKind.AddAccessorDeclaration;
-                case MethodKind.EventRemove:
-                    return SyntaxKind.RemoveAccessorDeclaration;
-                default:
-                    throw Exceptions.ThrowEUnexpected();
-            }
-        }
+                MethodKind.PropertyGet => SyntaxKind.GetAccessorDeclaration,
+                MethodKind.PropertySet => SyntaxKind.SetAccessorDeclaration,
+                MethodKind.EventAdd => SyntaxKind.AddAccessorDeclaration,
+                MethodKind.EventRemove => SyntaxKind.RemoveAccessorDeclaration,
+                _ => throw Exceptions.ThrowEUnexpected(),
+            };
 
         public override bool TryGetAccessorNode(SyntaxNode parentNode, MethodKind kind, out SyntaxNode accessorNode)
         {

src/Workspaces/Core/Portable/CodeStyle/CodeStyleOption.cs

@@ -121,26 +121,14 @@ public static CodeStyleOption<T> FromXElement(XElement element)
             var value = parser(valueAttribute.Value);
             var severity = (DiagnosticSeverity)Enum.Parse(typeof(DiagnosticSeverity), severityAttribute.Value);
 
-            NotificationOption notificationOption;
-            switch (severity)
+            return new CodeStyleOption<T>(value, severity switch
             {
-                case DiagnosticSeverity.Hidden:
-                    notificationOption = NotificationOption.Silent;
-                    break;
-                case DiagnosticSeverity.Info:
-                    notificationOption = NotificationOption.Suggestion;
-                    break;
-                case DiagnosticSeverity.Warning:
-                    notificationOption = NotificationOption.Warning;
-                    break;
-                case DiagnosticSeverity.Error:
-                    notificationOption = NotificationOption.Error;
-                    break;
-                default:
-                    throw new ArgumentException(nameof(element));
-            }
-
-            return new CodeStyleOption<T>(value, notificationOption);
+                DiagnosticSeverity.Hidden => NotificationOption.Silent,
+                DiagnosticSeverity.Info => NotificationOption.Suggestion,
+                DiagnosticSeverity.Warning => NotificationOption.Warning,
+                DiagnosticSeverity.Error => NotificationOption.Error,
+                _ => throw new ArgumentException(nameof(element)),
+            });
         }
 
         private static Func<string, T> GetParser(string type)

src/Workspaces/Core/Portable/Diagnostics/Extensions_SharedWithCodeStyle.cs

@@ -76,24 +76,13 @@ public static ReportDiagnostic WithDefaultSeverity(this ReportDiagnostic reportD
         /// If <paramref name="diagnosticSeverity"/> is not one of the expected values.
         /// </exception>
         public static ReportDiagnostic ToReportDiagnostic(this DiagnosticSeverity diagnosticSeverity)
-        {
-            switch (diagnosticSeverity)
+            => diagnosticSeverity switch
             {
-                case DiagnosticSeverity.Hidden:
-                    return ReportDiagnostic.Hidden;
-
-                case DiagnosticSeverity.Info:
-                    return ReportDiagnostic.Info;
-
-                case DiagnosticSeverity.Warning:
-                    return ReportDiagnostic.Warn;
-
-                case DiagnosticSeverity.Error:
-                    return ReportDiagnostic.Error;
-
-                default:
-                    throw ExceptionUtilities.UnexpectedValue(diagnosticSeverity);
-            }
-        }
+                DiagnosticSeverity.Hidden => ReportDiagnostic.Hidden,
+                DiagnosticSeverity.Info => ReportDiagnostic.Info,
+                DiagnosticSeverity.Warning => ReportDiagnostic.Warn,
+                DiagnosticSeverity.Error => ReportDiagnostic.Error,
+                _ => throw ExceptionUtilities.UnexpectedValue(diagnosticSeverity),
+            };
     }
 }

src/Workspaces/Remote/ServiceHub/Shared/RoslynJsonConverter.RoslynOnly.cs

@@ -357,22 +357,14 @@ protected override AddImportFixData ReadValue(JsonReader reader, JsonSerializer
                 Contract.ThrowIfFalse(reader.Read());
                 Contract.ThrowIfFalse(reader.TokenType == JsonToken.EndObject);
 
-                switch (kind)
+                return kind switch
                 {
-                    case AddImportFixKind.ProjectSymbol:
-                        return AddImportFixData.CreateForProjectSymbol(textChanges, title, tags, priority, projectReferenceToAdd);
-
-                    case AddImportFixKind.MetadataSymbol:
-                        return AddImportFixData.CreateForMetadataSymbol(textChanges, title, tags, priority, portableExecutableReferenceProjectId, portableExecutableReferenceFilePathToAdd);
-
-                    case AddImportFixKind.PackageSymbol:
-                        return AddImportFixData.CreateForPackageSymbol(textChanges, packageSource, packageName, packageVersionOpt);
-
-                    case AddImportFixKind.ReferenceAssemblySymbol:
-                        return AddImportFixData.CreateForReferenceAssemblySymbol(textChanges, title, assemblyReferenceAssemblyName, assemblyReferenceFullyQualifiedTypeName);
-                }
-
-                throw ExceptionUtilities.Unreachable;
+                    AddImportFixKind.ProjectSymbol => AddImportFixData.CreateForProjectSymbol(textChanges, title, tags, priority, projectReferenceToAdd),
+                    AddImportFixKind.MetadataSymbol => AddImportFixData.CreateForMetadataSymbol(textChanges, title, tags, priority, portableExecutableReferenceProjectId, portableExecutableReferenceFilePathToAdd),
+                    AddImportFixKind.PackageSymbol => AddImportFixData.CreateForPackageSymbol(textChanges, packageSource, packageName, packageVersionOpt),
+                    AddImportFixKind.ReferenceAssemblySymbol => AddImportFixData.CreateForReferenceAssemblySymbol(textChanges, title, assemblyReferenceAssemblyName, assemblyReferenceFullyQualifiedTypeName),
+                    _ => throw ExceptionUtilities.Unreachable,
+                };
             }
 
             protected override void WriteValue(JsonWriter writer, AddImportFixData source, JsonSerializer serializer)