code review feedback

src/EditorFeatures/Test2/IntelliSense/CSharpCompletionCommandHandlerTests.vb

@@ -204,6 +204,22 @@ class c { void M() { this.$$ToString() } }
             End Using
         End Function
 
+        <MemberData(NameOf(AllCompletionImplementations))>
+        <WpfTheory, Trait(Traits.Feature, Traits.Features.Completion)>
+        Public Async Function TestInvokingCompletionBetweenTwoDots(completionImplementation As CompletionImplementation) As Task
+            ' Starting C# 8.0 two dots are considered as a DotDotToken of a Range expression.
+            ' However, we may want to have a completion when invoking it aqfter the first dot.
+            Using state = TestStateFactory.CreateCSharpTestState(completionImplementation,
+                              <Document>
+class c { void M() { this.$$.ToString() } }
+                              </Document>)
+
+                state.SendInvokeCompletionList()
+                Await state.AssertCompletionSession()
+                Assert.True(state.CompletionItemsContainsAll({"ToString"}))
+            End Using
+        End Function
+
         <MemberData(NameOf(AllCompletionImplementations))>
         <WpfTheory, Trait(Traits.Feature, Traits.Features.Completion)>
         Public Async Function TestEnterIsConsumed(completionImplementation As CompletionImplementation) As Task

src/Workspaces/CSharp/Portable/Extensions/ContextQuery/CSharpSyntaxContext.cs

@@ -48,7 +48,7 @@ internal sealed class CSharpSyntaxContext : SyntaxContext
         public readonly bool IsCrefContext;
         public readonly bool IsCatchFilterContext;
         public readonly bool IsDestructorTypeContext;
-        public readonly bool IsFirstDotOfDotDotToken;
+        public readonly bool IsAfterFirstDotOfDotDot;
 
         private CSharpSyntaxContext(
             Workspace workspace,
@@ -100,7 +100,7 @@ internal sealed class CSharpSyntaxContext : SyntaxContext
             bool isDestructorTypeContext,
             bool isPossibleTupleContext,
             bool isPatternContext,
-            bool isFirstDotOfDotDotToken,
+            bool isAfterFirstDotOfDotDot,
             CancellationToken cancellationToken)
             : base(workspace, semanticModel, position, leftToken, targetToken,
                    isTypeContext, isNamespaceContext, isNamespaceDeclarationNameContext,
@@ -140,7 +140,7 @@ internal sealed class CSharpSyntaxContext : SyntaxContext
             this.IsCrefContext = isCrefContext;
             this.IsCatchFilterContext = isCatchFilterContext;
             this.IsDestructorTypeContext = isDestructorTypeContext;
-            this.IsFirstDotOfDotDotToken = isFirstDotOfDotDotToken;
+            this.IsAfterFirstDotOfDotDot = isAfterFirstDotOfDotDot;
         }
 
         public static CSharpSyntaxContext CreateContext(Workspace workspace, SemanticModel semanticModel, int position, CancellationToken cancellationToken)
@@ -198,8 +198,7 @@ private static CSharpSyntaxContext CreateContextWorker(Workspace workspace, Sema
                                             targetToken.Parent.IsKind(SyntaxKind.DestructorDeclaration) &&
                                             targetToken.Parent.Parent.IsKind(SyntaxKind.ClassDeclaration, SyntaxKind.StructDeclaration);
 
-            var isFirstDotOfDotDotToken = targetToken.IsKind(SyntaxKind.DotDotToken) &&
-                                                targetToken.Parent.IsKind(SyntaxKind.RangeExpression) &&
+            var isAfterFirstDotOfDotDot = targetToken.IsKind(SyntaxKind.DotDotToken) &&
                                                 position == targetToken.SpanStart + 1;
 
             return new CSharpSyntaxContext(
@@ -252,7 +251,7 @@ private static CSharpSyntaxContext CreateContextWorker(Workspace workspace, Sema
                 isDestructorTypeContext: isDestructorTypeContext,
                 isPossibleTupleContext: syntaxTree.IsPossibleTupleContext(leftToken, position),
                 isPatternContext: syntaxTree.IsPatternContext(leftToken, position),
-                isFirstDotOfDotDotToken: isFirstDotOfDotDotToken,
+                isAfterFirstDotOfDotDot: isAfterFirstDotOfDotDot,
                 cancellationToken: cancellationToken);
         }
 

src/Workspaces/CSharp/Portable/Recommendations/CSharpRecommendationService.cs

@@ -66,6 +66,7 @@ internal class CSharpRecommendationService : AbstractRecommendationService
             }
             else if (context.IsAnyExpressionContext ||
                      context.IsStatementContext ||
+                     context.IsAfterFirstDotOfDotDot ||
                      context.SyntaxTree.IsDefiniteCastTypeContext(context.Position, context.LeftToken, cancellationToken))
             {
                 // GitHub #717: With automatic brace completion active, typing '(i' produces "(i)", which gets parsed as
@@ -94,10 +95,6 @@ internal class CSharpRecommendationService : AbstractRecommendationService
             {
                 return GetSymbolsForNamespaceDeclarationNameContext(context, cancellationToken);
             }
-            else if (context.IsFirstDotOfDotDotToken)
-            {
-                return GetSymbolsForExpressionOrStatementContext(context, filterOutOfScopeLocals, cancellationToken);
-            }
 
             return ImmutableArray<ISymbol>.Empty;
         }