Merge pull request #23721 from zaytsev-victor/Fixed23672

Fixed incorrect suggestion for collection initialization simplification

src/EditorFeatures/CSharpTest/UseCollectionInitializer/UseCollectionInitializerTests.cs

@@ -1010,6 +1010,27 @@ public void Main()
 
         int horse = 1;
     }
+}");
+        }
+
+        [WorkItem(23672, "https://github.com/dotnet/roslyn/issues/23672")]
+        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUseCollectionInitializer)]
+        public async Task TestMissingWithExplicitImplementedAddMethod()
+        {
+            await TestMissingInRegularAndScriptAsync(
+@"
+using System.Collections.Generic;
+using System.Dynamic;
+
+public class Goo
+{
+    public void M()
+    {
+        IDictionary<string, object> obj = [||]new ExpandoObject();
+        obj.Add(""string"", ""v"");
+        obj.Add(""int"", 1);
+        obj.Add("" object"", new { X = 1, Y = 2 });
+        }
 }");
         }
     }

src/EditorFeatures/VisualBasicTest/UseCollectionInitializer/UseCollectionInitializerTests.vb

@@ -307,6 +307,22 @@ Class C
             2
         }
     End Sub
+End Class")
+        End Function
+
+        <WorkItem(23672, "https://github.com/dotnet/roslyn/pull/23672")>
+        <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUseCollectionInitializer)>
+        Public Async Function TestMissingWithExplicitImplementedAddMethod() As Task
+            Await TestMissingInRegularAndScriptAsync(
+"
+Imports System.Dynamic
+Imports System.Collections.Generic
+Class C
+    Sub M()
+        Dim obj As IDictionary(Of String, Object) = [||]New ExpandoObject()
+        obj.Add(""string"", ""v"")
+        obj.Add(""int"", 1)
+    End Sub
 End Class")
         End Function
     End Class

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

@@ -66,6 +66,11 @@ protected void Clear()
                 return null;
             }
 
+            if (!ShouldAnalyze())
+            {
+                return null;
+            }
+
             _containingStatement = _objectCreationExpression.FirstAncestorOrSelf<TStatementSyntax>();
             if (_containingStatement == null)
             {
@@ -179,5 +184,7 @@ protected bool ExpressionContainsValuePatternOrReferencesInitializedSymbol(Synta
 
             return false;
         }
+
+        protected abstract bool ShouldAnalyze();
     }
 }

src/Features/Core/Portable/UseCollectionInitializer/ObjectCreationExpressionAnalyzer.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.Collections;
 using System.Collections.Immutable;
+using System.Linq;
 using System.Threading;
 using Microsoft.CodeAnalysis.LanguageServices;
 using Microsoft.CodeAnalysis.PooledObjects;
-using Microsoft.CodeAnalysis.Shared.Extensions;
-using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.UseCollectionInitializer
 {
@@ -120,6 +118,23 @@ protected override void AddMatches(ArrayBuilder<TExpressionStatementSyntax> matc
             }
         }
 
+        protected override bool ShouldAnalyze()
+        {
+            var type = _semanticModel.GetTypeInfo(_objectCreationExpression, _cancellationToken).Type;
+            if (type == null)
+            {
+                return false;
+            }
+
+            var addMethods = _semanticModel.LookupSymbols(
+                _objectCreationExpression.SpanStart, 
+                container: type, 
+                name: WellKnownMemberNames.CollectionInitializerAddMethodName, 
+                includeReducedExtensionMethods: true);
+
+            return addMethods.Any(m => m is IMethodSymbol methodSymbol && methodSymbol.Parameters.Any());
+        }
+
         private bool TryAnalyzeIndexAssignment(
             TExpressionStatementSyntax statement,
             out SyntaxNode instance)
@@ -200,7 +215,7 @@ protected override void AddMatches(ArrayBuilder<TExpressionStatementSyntax> matc
             _syntaxFacts.GetPartsOfMemberAccessExpression(memberAccess, out var localInstance, out var memberName);
             _syntaxFacts.GetNameAndArityOfSimpleName(memberName, out var name, out var arity);
 
-            if (arity != 0 || !name.Equals(nameof(IList.Add)))
+            if (arity != 0 || !name.Equals(WellKnownMemberNames.CollectionInitializerAddMethodName))
             {
                 return false;
             }

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

@@ -164,6 +164,8 @@ protected override void AddMatches(ArrayBuilder<Match<TExpressionSyntax, TStatem
             }
         }
 
+        protected override bool ShouldAnalyze() => true;
+
         private bool ImplicitMemberAccessWouldBeAffected(SyntaxNode node)
         {
             if (node != null)