Add feature to generate a member name for an anonymous type.

src/Features/CSharp/Portable/AddAnonymousTypeMemberName/AddAnonymousTypeMemberNameCodeFixProvider.cs

+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+using System;
+using System.Collections.Immutable;
+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.Editing;
+using Microsoft.CodeAnalysis.LanguageServices;
+using Microsoft.CodeAnalysis.Shared.Extensions;
+
+namespace Microsoft.CodeAnalysis.CSharp.AddAnonymousTypeMemberName
+{
+    [ExportCodeFixProvider(LanguageNames.CSharp), Shared]
+    internal class AddAnonymousTypeMemberNameCodeFixProvider : SyntaxEditorBasedCodeFixProvider
+    {
+        private const string CS0746 = nameof(CS0746); // Invalid anonymous type member declarator. Anonymous type members must be declared with a member assignment, simple name or member access.
+
+        public override ImmutableArray<string> FixableDiagnosticIds { get; }
+            = ImmutableArray.Create(CS0746);
+
+        public override async Task RegisterCodeFixesAsync(CodeFixContext context)
+        {
+            var document = context.Document;
+            var cancellationToken = context.CancellationToken;
+
+            var diagnostic = context.Diagnostics[0];
+            var declarator = await GetMemberDeclaratorAsync(document, diagnostic, cancellationToken).ConfigureAwait(false);
+            if (declarator == null)
+            {
+                return;
+            }
+
+            context.RegisterCodeFix(
+                new MyCodeAction(c => FixAsync(document, diagnostic, c)),
+                context.Diagnostics);
+        }
+
+        private async Task<AnonymousObjectMemberDeclaratorSyntax> GetMemberDeclaratorAsync(
+            Document document, Diagnostic diagnostic, CancellationToken cancellationToken)
+        {
+            var span = diagnostic.Location.SourceSpan;
+            var root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
+            var node = root.FindNode(span, getInnermostNodeForTie: true) as ExpressionSyntax;
+            if (node?.Span != span)
+            {
+                return null;
+            }
+
+            if (!(node.Parent is AnonymousObjectMemberDeclaratorSyntax declarator))
+            {
+                return null;
+            }
+
+            // Can't add a name of the declarator already has a name.
+            if (declarator.NameEquals != null)
+            {
+                return null;
+            }
+
+            return declarator;
+        }
+
+        protected override async Task FixAllAsync(
+            Document document, ImmutableArray<Diagnostic> diagnostics,
+            SyntaxEditor editor, CancellationToken cancellationToken)
+        {
+            var semanticModel = await document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
+            foreach (var diagnostic in diagnostics)
+            {
+                await FixOneAsync(
+                    document, semanticModel, diagnostic, 
+                    editor, cancellationToken).ConfigureAwait(false);
+            }
+        }
+
+        private async Task FixOneAsync(
+            Document document, SemanticModel semanticModel, Diagnostic diagnostic, 
+            SyntaxEditor editor, CancellationToken cancellationToken)
+        {
+            var declarator = await GetMemberDeclaratorAsync(document, diagnostic, cancellationToken).ConfigureAwait(false);
+            if (declarator == null)
+            {
+                return;
+            }
+
+            var semanticFacts = document.GetLanguageService<ISemanticFactsService>();
+            var name = semanticFacts.GenerateNameForExpression(semanticModel, declarator.Expression, capitalize: true, cancellationToken);
+            if (string.IsNullOrEmpty(name))
+            {
+                return;
+            }
+
+            editor.ReplaceNode(
+                declarator,
+                (current, _) =>
+                {
+                    var currentDeclarator = (AnonymousObjectMemberDeclaratorSyntax)current;
+                    return currentDeclarator.WithNameEquals(SyntaxFactory.NameEquals(name));
+                });
+        }
+
+        private class MyCodeAction : CodeAction.DocumentChangeAction
+        {
+            public MyCodeAction(Func<CancellationToken, Task<Document>> createChangedDocument) 
+                : base(FeaturesResources.Add_member_name, createChangedDocument)
+            {
+            }
+        }
+    }
+}

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

@@ -179,6 +179,15 @@ internal class FeaturesResources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Add member name.
+        /// </summary>
+        internal static string Add_member_name {
+            get {
+                return ResourceManager.GetString("Add_member_name", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Add missing cases.
         /// </summary>
@@ -941,7 +950,7 @@ internal class FeaturesResources {
                 return ResourceManager.GetString("Convert_to_query", resourceCulture);
             }
         }
-
+        
         /// <summary>
         ///   Looks up a localized string similar to Convert to struct.
         /// </summary>

src/Features/Core/Portable/FeaturesResources.resx

@@ -1403,4 +1403,7 @@ This version used in: {2}</value>
   <data name="Formatting_document" xml:space="preserve">
     <value>Formatting document</value>
   </data>
+  <data name="Add_member_name" xml:space="preserve">
+    <value>Add member name</value>
+  </data>
 </root>
\ No newline at end of file

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

@@ -2,6 +2,11 @@
 <xliff xmlns="urn:oasis:names:tc:xliff:document:1.2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.2" xsi:schemaLocation="urn:oasis:names:tc:xliff:document:1.2 xliff-core-1.2-transitional.xsd">
   <file datatype="xml" source-language="en" target-language="cs" original="../FeaturesResources.resx">
     <body>
+      <trans-unit id="Add_member_name">
+        <source>Add member name</source>
+        <target state="new">Add member name</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Add_parameter_to_0_and_overrides_implementations">
         <source>Add parameter to '{0}' (and overrides/implementations)</source>
         <target state="new">Add parameter to '{0}' (and overrides/implementations)</target>

src/Features/Core/Portable/xlf/FeaturesResources.de.xlf

@@ -2,6 +2,11 @@
 <xliff xmlns="urn:oasis:names:tc:xliff:document:1.2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.2" xsi:schemaLocation="urn:oasis:names:tc:xliff:document:1.2 xliff-core-1.2-transitional.xsd">
   <file datatype="xml" source-language="en" target-language="de" original="../FeaturesResources.resx">
     <body>
+      <trans-unit id="Add_member_name">
+        <source>Add member name</source>
+        <target state="new">Add member name</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Add_parameter_to_0_and_overrides_implementations">
         <source>Add parameter to '{0}' (and overrides/implementations)</source>
         <target state="new">Add parameter to '{0}' (and overrides/implementations)</target>

src/Features/Core/Portable/xlf/FeaturesResources.es.xlf

@@ -2,6 +2,11 @@
 <xliff xmlns="urn:oasis:names:tc:xliff:document:1.2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.2" xsi:schemaLocation="urn:oasis:names:tc:xliff:document:1.2 xliff-core-1.2-transitional.xsd">
   <file datatype="xml" source-language="en" target-language="es" original="../FeaturesResources.resx">
     <body>
+      <trans-unit id="Add_member_name">
+        <source>Add member name</source>
+        <target state="new">Add member name</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Add_parameter_to_0_and_overrides_implementations">
         <source>Add parameter to '{0}' (and overrides/implementations)</source>
         <target state="new">Add parameter to '{0}' (and overrides/implementations)</target>

src/Features/Core/Portable/xlf/FeaturesResources.fr.xlf

@@ -2,6 +2,11 @@
 <xliff xmlns="urn:oasis:names:tc:xliff:document:1.2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.2" xsi:schemaLocation="urn:oasis:names:tc:xliff:document:1.2 xliff-core-1.2-transitional.xsd">
   <file datatype="xml" source-language="en" target-language="fr" original="../FeaturesResources.resx">
     <body>
+      <trans-unit id="Add_member_name">
+        <source>Add member name</source>
+        <target state="new">Add member name</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Add_parameter_to_0_and_overrides_implementations">
         <source>Add parameter to '{0}' (and overrides/implementations)</source>
         <target state="new">Add parameter to '{0}' (and overrides/implementations)</target>

src/Features/Core/Portable/xlf/FeaturesResources.it.xlf

@@ -2,6 +2,11 @@
 <xliff xmlns="urn:oasis:names:tc:xliff:document:1.2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.2" xsi:schemaLocation="urn:oasis:names:tc:xliff:document:1.2 xliff-core-1.2-transitional.xsd">
   <file datatype="xml" source-language="en" target-language="it" original="../FeaturesResources.resx">
     <body>
+      <trans-unit id="Add_member_name">
+        <source>Add member name</source>
+        <target state="new">Add member name</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Add_parameter_to_0_and_overrides_implementations">
         <source>Add parameter to '{0}' (and overrides/implementations)</source>
         <target state="new">Add parameter to '{0}' (and overrides/implementations)</target>

src/Features/Core/Portable/xlf/FeaturesResources.ja.xlf

@@ -2,6 +2,11 @@
 <xliff xmlns="urn:oasis:names:tc:xliff:document:1.2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.2" xsi:schemaLocation="urn:oasis:names:tc:xliff:document:1.2 xliff-core-1.2-transitional.xsd">
   <file datatype="xml" source-language="en" target-language="ja" original="../FeaturesResources.resx">
     <body>
+      <trans-unit id="Add_member_name">
+        <source>Add member name</source>
+        <target state="new">Add member name</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Add_parameter_to_0_and_overrides_implementations">
         <source>Add parameter to '{0}' (and overrides/implementations)</source>
         <target state="new">Add parameter to '{0}' (and overrides/implementations)</target>

src/Features/Core/Portable/xlf/FeaturesResources.ko.xlf

@@ -2,6 +2,11 @@
 <xliff xmlns="urn:oasis:names:tc:xliff:document:1.2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.2" xsi:schemaLocation="urn:oasis:names:tc:xliff:document:1.2 xliff-core-1.2-transitional.xsd">
   <file datatype="xml" source-language="en" target-language="ko" original="../FeaturesResources.resx">
     <body>
+      <trans-unit id="Add_member_name">
+        <source>Add member name</source>
+        <target state="new">Add member name</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Add_parameter_to_0_and_overrides_implementations">
         <source>Add parameter to '{0}' (and overrides/implementations)</source>
         <target state="new">Add parameter to '{0}' (and overrides/implementations)</target>

src/Features/Core/Portable/xlf/FeaturesResources.pl.xlf

@@ -2,6 +2,11 @@
 <xliff xmlns="urn:oasis:names:tc:xliff:document:1.2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.2" xsi:schemaLocation="urn:oasis:names:tc:xliff:document:1.2 xliff-core-1.2-transitional.xsd">
   <file datatype="xml" source-language="en" target-language="pl" original="../FeaturesResources.resx">
     <body>
+      <trans-unit id="Add_member_name">
+        <source>Add member name</source>
+        <target state="new">Add member name</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Add_parameter_to_0_and_overrides_implementations">
         <source>Add parameter to '{0}' (and overrides/implementations)</source>
         <target state="new">Add parameter to '{0}' (and overrides/implementations)</target>

src/Features/Core/Portable/xlf/FeaturesResources.pt-BR.xlf

@@ -2,6 +2,11 @@
 <xliff xmlns="urn:oasis:names:tc:xliff:document:1.2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.2" xsi:schemaLocation="urn:oasis:names:tc:xliff:document:1.2 xliff-core-1.2-transitional.xsd">
   <file datatype="xml" source-language="en" target-language="pt-BR" original="../FeaturesResources.resx">
     <body>
+      <trans-unit id="Add_member_name">
+        <source>Add member name</source>
+        <target state="new">Add member name</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Add_parameter_to_0_and_overrides_implementations">
         <source>Add parameter to '{0}' (and overrides/implementations)</source>
         <target state="new">Add parameter to '{0}' (and overrides/implementations)</target>

src/Features/Core/Portable/xlf/FeaturesResources.ru.xlf

@@ -2,6 +2,11 @@
 <xliff xmlns="urn:oasis:names:tc:xliff:document:1.2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.2" xsi:schemaLocation="urn:oasis:names:tc:xliff:document:1.2 xliff-core-1.2-transitional.xsd">
   <file datatype="xml" source-language="en" target-language="ru" original="../FeaturesResources.resx">
     <body>
+      <trans-unit id="Add_member_name">
+        <source>Add member name</source>
+        <target state="new">Add member name</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Add_parameter_to_0_and_overrides_implementations">
         <source>Add parameter to '{0}' (and overrides/implementations)</source>
         <target state="new">Add parameter to '{0}' (and overrides/implementations)</target>

src/Features/Core/Portable/xlf/FeaturesResources.tr.xlf

@@ -2,6 +2,11 @@
 <xliff xmlns="urn:oasis:names:tc:xliff:document:1.2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.2" xsi:schemaLocation="urn:oasis:names:tc:xliff:document:1.2 xliff-core-1.2-transitional.xsd">
   <file datatype="xml" source-language="en" target-language="tr" original="../FeaturesResources.resx">
     <body>
+      <trans-unit id="Add_member_name">
+        <source>Add member name</source>
+        <target state="new">Add member name</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Add_parameter_to_0_and_overrides_implementations">
         <source>Add parameter to '{0}' (and overrides/implementations)</source>
         <target state="new">Add parameter to '{0}' (and overrides/implementations)</target>

src/Features/Core/Portable/xlf/FeaturesResources.zh-Hans.xlf

@@ -2,6 +2,11 @@
 <xliff xmlns="urn:oasis:names:tc:xliff:document:1.2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.2" xsi:schemaLocation="urn:oasis:names:tc:xliff:document:1.2 xliff-core-1.2-transitional.xsd">
   <file datatype="xml" source-language="en" target-language="zh-Hans" original="../FeaturesResources.resx">
     <body>
+      <trans-unit id="Add_member_name">
+        <source>Add member name</source>
+        <target state="new">Add member name</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Add_parameter_to_0_and_overrides_implementations">
         <source>Add parameter to '{0}' (and overrides/implementations)</source>
         <target state="new">Add parameter to '{0}' (and overrides/implementations)</target>

src/Features/Core/Portable/xlf/FeaturesResources.zh-Hant.xlf

@@ -2,6 +2,11 @@
 <xliff xmlns="urn:oasis:names:tc:xliff:document:1.2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.2" xsi:schemaLocation="urn:oasis:names:tc:xliff:document:1.2 xliff-core-1.2-transitional.xsd">
   <file datatype="xml" source-language="en" target-language="zh-Hant" original="../FeaturesResources.resx">
     <body>
+      <trans-unit id="Add_member_name">
+        <source>Add member name</source>
+        <target state="new">Add member name</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Add_parameter_to_0_and_overrides_implementations">
         <source>Add parameter to '{0}' (and overrides/implementations)</source>
         <target state="new">Add parameter to '{0}' (and overrides/implementations)</target>