fixed symbol decoding from completion items

CHANGELOG.md

@@ -2,6 +2,7 @@
 All changes to the project will be documented in this file.
 
 ## [1.34.10] - not yet released
+* Fixed a bug where completion items didn't decode symbols corectly (impacted, for example, object initializer completion quality) ([omnisharp-vscode#3465](https://github.com/OmniSharp/omnisharp-vscode/issues/3465), PR: [#1670](https://github.com/OmniSharp/omnisharp-roslyn/pull/1670))
 * Updated to MsBuild 16.4.0 on Linux/MacOS (PR:[#1669](https://github.com/OmniSharp/omnisharp-roslyn/pull/1669))
 
 ## [1.34.9] - 2019-12-10

src/OmniSharp.Roslyn.CSharp/Services/Intellisense/CompletionItemExtensions.cs

@@ -21,7 +21,6 @@ internal static class CompletionItemExtensions
         private const string ParitalMethodCompletionProvider = "Microsoft.CodeAnalysis.CSharp.Completion.Providers.PartialMethodCompletionProvider";
         private const string ProviderName = nameof(ProviderName);
         private const string SymbolCompletionItem = "Microsoft.CodeAnalysis.Completion.Providers.SymbolCompletionItem";
-        private const string SymbolCompletionProvider = "Microsoft.CodeAnalysis.CSharp.Completion.Providers.SymbolCompletionProvider";
         private const string SymbolKind = nameof(SymbolKind);
         private const string SymbolName = nameof(SymbolName);
         private const string Symbols = nameof(Symbols);
@@ -49,7 +48,9 @@ public static bool IsObjectCreationCompletionItem(this CompletionItem item)
 
         public static async Task<IEnumerable<ISymbol>> GetCompletionSymbolsAsync(this CompletionItem completionItem, IEnumerable<ISymbol> recommendedSymbols, Document document)
         {
-            if (completionItem.GetType() == _symbolCompletionItemType)
+            var properties = completionItem.Properties;
+
+            if (completionItem.GetType() == _symbolCompletionItemType || properties.ContainsKey(Symbols))
             {
                 var decodedSymbolsTask = _getSymbolsAsync.InvokeStatic<Task<ImmutableArray<ISymbol>>>(new object[] { completionItem, document, default(CancellationToken) });
                 if (decodedSymbolsTask != null)
@@ -58,8 +59,6 @@ public static async Task<IEnumerable<ISymbol>> GetCompletionSymbolsAsync(this Co
                 }
             }
 
-            var properties = completionItem.Properties;
-
             // if the completion provider encoded symbols into Properties, we can return them
             if (properties.ContainsKey(SymbolName) && properties.ContainsKey(SymbolKind))
             {

tests/OmniSharp.Roslyn.CSharp.Tests/IntellisenseFacts.cs

@@ -259,6 +259,7 @@ public MyClass2()
 
             var completions = await FindCompletionsAsync(filename, source);
             ContainsCompletions(completions.Select(c => c.CompletionText), "Foo");
+            ContainsCompletions(completions.Select(c => c.ReturnType), "string");
         }
 
         [Theory]