Improve the messages we give for code fixes in the error list.

src/Features/CSharp/Portable/InlineDeclaration/CSharpInlineDeclarationDiagnosticAnalyzer.cs

@@ -26,7 +26,8 @@ internal class CSharpInlineDeclarationDiagnosticAnalyzer : AbstractCodeStyleDiag
     {
         public CSharpInlineDeclarationDiagnosticAnalyzer()
             : base(IDEDiagnosticIds.InlineDeclarationDiagnosticId,
-                   new LocalizableResourceString(nameof(FeaturesResources.Inline_variable_declaration), FeaturesResources.ResourceManager, typeof(FeaturesResources)))
+                   new LocalizableResourceString(nameof(FeaturesResources.Inline_variable_declaration), FeaturesResources.ResourceManager, typeof(FeaturesResources)),
+                   new LocalizableResourceString(nameof(FeaturesResources.Variable_declaration_can_be_inlined), FeaturesResources.ResourceManager, typeof(FeaturesResources)))
         {
         }
 
@@ -196,7 +197,7 @@ private void AnalyzeSyntaxNode(SyntaxNodeAnalysisContext context)
                 : localDeclarator;
 
             context.ReportDiagnostic(Diagnostic.Create(
-                CreateDescriptor(this.DescriptorId, option.Notification.Value),
+                CreateDescriptorWithSeverity(option.Notification.Value),
                 reportNode.GetLocation(),
                 additionalLocations: allLocations));
         }

src/Features/CSharp/Portable/InvokeDelegateWithConditionalAccess/InvokeDelegateWithConditionalAccessAnalyzer.cs

@@ -173,7 +173,8 @@ private void SyntaxNodeAction(SyntaxNodeAnalysisContext syntaxContext)
                 additionalLocations, properties));
 
             // Put a diagnostic with the appropriate severity on the expression-statement itself.
-            syntaxContext.ReportDiagnostic(Diagnostic.Create(CreateDescriptor(this.DescriptorId, severity),
+            syntaxContext.ReportDiagnostic(Diagnostic.Create(
+                CreateDescriptorWithSeverity(severity),
                 expressionStatement.GetLocation(),
                 additionalLocations, properties));
 

src/Features/CSharp/Portable/UseExpressionBody/AbstractUseExpressionBodyDiagnosticAnalyzer.cs

@@ -65,7 +65,7 @@ internal virtual Diagnostic AnalyzeSyntax(OptionSet optionSet, TDeclaration decl
                     {
                         var additionalLocations = ImmutableArray.Create(declaration.GetLocation());
                         return Diagnostic.Create(
-                            CreateDescriptor(_expressionBodyTitle, preferExpressionBodiedOption.Notification.Value),
+                            CreateDescriptorWithTitle(_expressionBodyTitle, preferExpressionBodiedOption.Notification.Value),
                             GetBody(declaration).Statements[0].GetLocation(),
                             additionalLocations: additionalLocations);
                     }
@@ -78,7 +78,7 @@ internal virtual Diagnostic AnalyzeSyntax(OptionSet optionSet, TDeclaration decl
                 {
                     var additionalLocations = ImmutableArray.Create(declaration.GetLocation());
                     return Diagnostic.Create(
-                        CreateDescriptor(_blockBodyTitle, preferExpressionBodiedOption.Notification.Value),
+                        CreateDescriptorWithTitle(_blockBodyTitle, preferExpressionBodiedOption.Notification.Value),
                         expressionBody.GetLocation(),
                         additionalLocations: additionalLocations);
                 }

src/Features/CSharp/Portable/UsePatternMatching/CSharpAsAndNullCheckDiagnosticAnalyzer.cs

@@ -132,7 +132,7 @@ private void SyntaxNodeAction(SyntaxNodeAnalysisContext syntaxContext)
 
             // Put a diagnostic with the appropriate severity on the declaration-statement itself.
             syntaxContext.ReportDiagnostic(Diagnostic.Create(
-                CreateDescriptor(this.DescriptorId, severity),
+                CreateDescriptorWithSeverity(severity),
                 localDeclarationStatement.GetLocation(),
                 additionalLocations));
         }

src/Features/CSharp/Portable/UsePatternMatching/CSharpIsAndCastCheckDiagnosticAnalyzer.cs

@@ -142,7 +142,7 @@ private void SyntaxNodeAction(SyntaxNodeAnalysisContext syntaxContext)
 
             // Put a diagnostic with the appropriate severity on the declaration-statement itself.
             syntaxContext.ReportDiagnostic(Diagnostic.Create(
-                CreateDescriptor(this.DescriptorId, severity),
+                CreateDescriptorWithSeverity(severity),
                 localDeclarationStatement.GetLocation(),
                 additionalLocations));
         }

src/Features/Core/Portable/CodeStyle/AbstractCodeStyleDiagnosticAnalyzer.cs

@@ -39,13 +39,13 @@ internal abstract class AbstractCodeStyleDiagnosticAnalyzer : DiagnosticAnalyzer
             _localizableTitle = title;
             _localizableMessage = message ?? title;
 
-            var primaryDescriptor = CreateDescriptor(descriptorId, DiagnosticSeverity.Hidden);
+            var primaryDescriptor = CreateDescriptorWithSeverity(DiagnosticSeverity.Hidden);
 
-            UnnecessaryWithSuggestionDescriptor = CreateDescriptor(
+            UnnecessaryWithSuggestionDescriptor = CreateDescriptorWithId(
                 descriptorId, _localizableTitle, _localizableMessage, 
                 DiagnosticSeverity.Hidden, DiagnosticCustomTags.Unnecessary);
 
-            UnnecessaryWithoutSuggestionDescriptor = CreateDescriptor(
+            UnnecessaryWithoutSuggestionDescriptor = CreateDescriptorWithId(
                 descriptorId + "WithoutSuggestion",
                 _localizableTitle, _localizableMessage, 
                 DiagnosticSeverity.Hidden, DiagnosticCustomTags.Unnecessary);
@@ -56,13 +56,13 @@ internal abstract class AbstractCodeStyleDiagnosticAnalyzer : DiagnosticAnalyzer
 
         public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics { get; }
 
-        protected DiagnosticDescriptor CreateDescriptor(DiagnosticSeverity severity, params string[] customTags)
-            => CreateDescriptor(DescriptorId, _localizableTitle, _localizableMessage, severity, customTags);
+        protected DiagnosticDescriptor CreateDescriptorWithSeverity(DiagnosticSeverity severity, params string[] customTags)
+            => CreateDescriptorWithId(DescriptorId, _localizableTitle, _localizableMessage, severity, customTags);
 
-        protected DiagnosticDescriptor CreateDescriptor(LocalizableString title, DiagnosticSeverity severity, params string[] customTags)
-            => CreateDescriptor(DescriptorId, title, title, severity, customTags);
+        protected DiagnosticDescriptor CreateDescriptorWithTitle(LocalizableString title, DiagnosticSeverity severity, params string[] customTags)
+            => CreateDescriptorWithId(DescriptorId, title, title, severity, customTags);
 
-        private DiagnosticDescriptor CreateDescriptor(string id, LocalizableString title, LocalizableString message, DiagnosticSeverity severity, params string[] customTags)
+        private DiagnosticDescriptor CreateDescriptorWithId(string id, LocalizableString title, LocalizableString message, DiagnosticSeverity severity, params string[] customTags)
             => new DiagnosticDescriptor(
                 id, title, message,
                 DiagnosticCategory.Style,

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

@@ -2011,6 +2011,15 @@ internal class FeaturesResources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Null check can be simplified.
+        /// </summary>
+        internal static string Null_check_can_be_simplified {
+            get {
+                return ResourceManager.GetString("Null_check_can_be_simplified", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Object initialization can be simplified.
         /// </summary>
@@ -2412,6 +2421,15 @@ internal class FeaturesResources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Simplify collection initialization.
+        /// </summary>
+        internal static string Simplify_collection_initialization {
+            get {
+                return ResourceManager.GetString("Simplify_collection_initialization", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Simplify Member Access.
         /// </summary>
@@ -2430,6 +2448,15 @@ internal class FeaturesResources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Simplify object initialization.
+        /// </summary>
+        internal static string Simplify_object_initialization {
+            get {
+                return ResourceManager.GetString("Simplify_object_initialization", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Snippets.
         /// </summary>
@@ -3164,6 +3191,15 @@ internal class FeaturesResources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Variable declaration can be inlined.
+        /// </summary>
+        internal static string Variable_declaration_can_be_inlined {
+            get {
+                return ResourceManager.GetString("Variable_declaration_can_be_inlined", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Variadic SignatureHelpItem must have at least one parameter..
         /// </summary>

src/Features/Core/Portable/FeaturesResources.resx

@@ -1157,4 +1157,16 @@ This version used in: {2}</value>
   <data name="Use_null_propagation" xml:space="preserve">
     <value>Use null propagation</value>
   </data>
+  <data name="Variable_declaration_can_be_inlined" xml:space="preserve">
+    <value>Variable declaration can be inlined</value>
+  </data>
+  <data name="Null_check_can_be_simplified" xml:space="preserve">
+    <value>Null check can be simplified</value>
+  </data>
+  <data name="Simplify_collection_initialization" xml:space="preserve">
+    <value>Simplify collection initialization</value>
+  </data>
+  <data name="Simplify_object_initialization" xml:space="preserve">
+    <value>Simplify object initialization</value>
+  </data>
 </root>
\ No newline at end of file

src/Features/Core/Portable/QualifyMemberAccess/AbstractQualifyMemberAccessDiagnosticAnalyzer.cs

@@ -88,7 +88,7 @@ private void AnalyzeOperation(OperationAnalysisContext context)
                 if (severity != DiagnosticSeverity.Hidden)
                 {
                     context.ReportDiagnostic(Diagnostic.Create(
-                        CreateDescriptor(severity), 
+                        CreateDescriptorWithSeverity(severity), 
                         context.Operation.Syntax.GetLocation()));
                 }
             }

src/Features/Core/Portable/UseCoalesceExpression/AbstractUseCoalesceExpressionDiagnosticAnalyzer.cs

@@ -19,7 +19,8 @@ internal abstract class AbstractUseCoalesceExpressionDiagnosticAnalyzer<
     {
         protected AbstractUseCoalesceExpressionDiagnosticAnalyzer() 
             : base(IDEDiagnosticIds.UseCoalesceExpressionDiagnosticId,
-                   new LocalizableResourceString(nameof(FeaturesResources.Use_coalesce_expression), FeaturesResources.ResourceManager, typeof(FeaturesResources)))
+                   new LocalizableResourceString(nameof(FeaturesResources.Use_coalesce_expression), FeaturesResources.ResourceManager, typeof(FeaturesResources)),
+                   new LocalizableResourceString(nameof(FeaturesResources.Null_check_can_be_simplified), FeaturesResources.ResourceManager, typeof(FeaturesResources)))
         {
         }
 
@@ -103,7 +104,7 @@ private void AnalyzeSyntax(SyntaxNodeAnalysisContext context)
                 whenPartToCheck.GetLocation());
 
             context.ReportDiagnostic(Diagnostic.Create(
-                this.CreateDescriptor(option.Notification.Value),
+                this.CreateDescriptorWithSeverity(option.Notification.Value),
                 conditionalExpression.GetLocation(),
                 locations));
         }

src/Features/Core/Portable/UseCoalesceExpression/AbstractUseCoalesceExpressionForNullableDiagnosticAnalyzer.cs

@@ -129,7 +129,7 @@ private void AnalyzeSyntax(SyntaxNodeAnalysisContext context)
                 whenPartToKeep.GetLocation());
 
             context.ReportDiagnostic(Diagnostic.Create(
-                this.CreateDescriptor(option.Notification.Value),
+                this.CreateDescriptorWithSeverity(option.Notification.Value),
                 conditionalExpression.GetLocation(),
                 locations));
         }

src/Features/Core/Portable/UseCollectionInitializer/AbstractUseCollectionInitializerDiagnosticAnalyzer.cs

@@ -33,6 +33,7 @@ internal abstract class AbstractUseCollectionInitializerDiagnosticAnalyzer<
 
         protected AbstractUseCollectionInitializerDiagnosticAnalyzer() 
             : base(IDEDiagnosticIds.UseCollectionInitializerDiagnosticId,
+                   new LocalizableResourceString(nameof(FeaturesResources.Simplify_collection_initialization), FeaturesResources.ResourceManager, typeof(FeaturesResources)),
                    new LocalizableResourceString(nameof(FeaturesResources.Collection_initialization_can_be_simplified), FeaturesResources.ResourceManager, typeof(FeaturesResources)))
         {
         }
@@ -96,7 +97,7 @@ private void AnalyzeNode(SyntaxNodeAnalysisContext context, INamedTypeSymbol ien
 
             var severity = option.Notification.Value;
             context.ReportDiagnostic(Diagnostic.Create(
-                CreateDescriptor(severity),
+                CreateDescriptorWithSeverity(severity),
                 objectCreationExpression.GetLocation(),
                 additionalLocations: locations));
 

src/Features/Core/Portable/UseNullPropagation/AbstractUseNullPropagationDiagnosticAnalyzer.cs

@@ -28,7 +28,8 @@ internal abstract class AbstractUseNullPropagationDiagnosticAnalyzer<
     {
         protected AbstractUseNullPropagationDiagnosticAnalyzer()
             : base(IDEDiagnosticIds.UseNullPropagationDiagnosticId,
-                   new LocalizableResourceString(nameof(FeaturesResources.Use_null_propagation), FeaturesResources.ResourceManager, typeof(FeaturesResources)))
+                   new LocalizableResourceString(nameof(FeaturesResources.Use_null_propagation), FeaturesResources.ResourceManager, typeof(FeaturesResources)),
+                   new LocalizableResourceString(nameof(FeaturesResources.Null_check_can_be_simplified), FeaturesResources.ResourceManager, typeof(FeaturesResources)))
         {
         }
 
@@ -112,7 +113,7 @@ private void AnalyzeSyntax(SyntaxNodeAnalysisContext context)
                 whenPartToCheck.GetLocation());
 
             context.ReportDiagnostic(Diagnostic.Create(
-                this.CreateDescriptor(option.Notification.Value),
+                this.CreateDescriptorWithSeverity(option.Notification.Value),
                 conditionalExpression.GetLocation(),
                 locations));
         }

src/Features/Core/Portable/UseObjectInitializer/AbstractUseObjectInitializerDiagnosticAnalyzer.cs

@@ -35,6 +35,7 @@ internal abstract class AbstractUseObjectInitializerDiagnosticAnalyzer<
 
         protected AbstractUseObjectInitializerDiagnosticAnalyzer() 
             : base(IDEDiagnosticIds.UseObjectInitializerDiagnosticId,
+                  new LocalizableResourceString(nameof(FeaturesResources.Simplify_object_initialization), FeaturesResources.ResourceManager, typeof(FeaturesResources)),
                    new LocalizableResourceString(nameof(FeaturesResources.Object_initialization_can_be_simplified), FeaturesResources.ResourceManager, typeof(FeaturesResources)))
         {
         }
@@ -80,7 +81,7 @@ private void AnalyzeNode(SyntaxNodeAnalysisContext context)
 
             var severity = option.Notification.Value;
             context.ReportDiagnostic(Diagnostic.Create(
-                CreateDescriptor(severity),
+                CreateDescriptorWithSeverity(severity),
                 objectCreationExpression.GetLocation(),
                 additionalLocations: locations));
 

src/Features/Core/Portable/UseThrowExpression/AbstractUseThrowExpressionDiagnosticAnalyzer.cs

@@ -36,7 +36,8 @@ internal abstract class AbstractUseThrowExpressionDiagnosticAnalyzer : AbstractC
     {
         protected AbstractUseThrowExpressionDiagnosticAnalyzer()
             : base(IDEDiagnosticIds.UseThrowExpressionDiagnosticId,
-                   new LocalizableResourceString(nameof(FeaturesResources.Use_throw_expression), FeaturesResources.ResourceManager, typeof(FeaturesResources)))
+                   new LocalizableResourceString(nameof(FeaturesResources.Use_throw_expression), FeaturesResources.ResourceManager, typeof(FeaturesResources)),
+                   new LocalizableResourceString(nameof(FeaturesResources.Null_check_can_be_simplified), FeaturesResources.ResourceManager, typeof(FeaturesResources)))
         {
         }
 
@@ -141,7 +142,7 @@ private void AnalyzeOperation(OperationAnalysisContext context)
                 throwOperation.ThrownObject.Syntax.GetLocation(),
                 assignmentExpression.Value.Syntax.GetLocation());
 
-            var descriptor = CreateDescriptor(option.Notification.Value);
+            var descriptor = CreateDescriptorWithSeverity(option.Notification.Value);
 
             context.ReportDiagnostic(
                 Diagnostic.Create(descriptor, throwStatement.GetLocation(), additionalLocations: allLocations));