Fix handling of partial definition deletes (#77735)

Author: tmat

src/Features/CSharpTest/EditAndContinue/TopLevelEditingTests.cs

@@ -10257,6 +10257,17 @@ public void Method_Partial_DeleteImplementation()
             ]);
     }
 
+    [Fact]
+    public void Method_Partial_DeleteDefinition()
+    {
+        var src1 = "partial class C { partial void F(); }";
+        var src2 = "partial class C { }";
+
+        var edits = GetTopEdits(src1, src2);
+
+        edits.VerifySemantics();
+    }
+
     [Fact]
     public void Method_Partial_DeleteBoth()
     {
@@ -10269,8 +10280,7 @@ public void Method_Partial_DeleteBoth()
         EditAndContinueValidation.VerifySemantics(
             [GetTopEdits(srcA1, srcA2), GetTopEdits(srcB1, srcB2)],
             [
-                DocumentResults(
-                    semanticEdits: [SemanticEdit(SemanticEditKind.Delete, c => c.GetMember<IMethodSymbol>("C.F").PartialImplementationPart, deletedSymbolContainerProvider: c => c.GetMember("C"), partialType: "C")]),
+                DocumentResults(),
                 DocumentResults(
                     semanticEdits: [SemanticEdit(SemanticEditKind.Delete, c => c.GetMember<IMethodSymbol>("C.F").PartialImplementationPart, deletedSymbolContainerProvider: c => c.GetMember("C"), partialType: "C")]),
             ]);
@@ -11830,11 +11840,7 @@ public void Constructor_Parameter_Insert_Primary_Record_WithCustomDeconstructor_
                         SemanticEdit(SemanticEditKind.Delete, c => c.GetPrimaryConstructor("C"), deletedSymbolContainerProvider: c => c.GetMember("C")),
                         SemanticEdit(SemanticEditKind.Insert, c => c.GetPrimaryConstructor("C")),
                     ]),
-                DocumentResults(
-                   semanticEdits:
-                   [
-                        SemanticEdit(SemanticEditKind.Delete, c => c.GetPrimaryDeconstructor("C").PartialImplementationPart, deletedSymbolContainerProvider: c => c.GetMember("C"), partialType: "C"),
-                   ]),
+                DocumentResults(),
             ],
             capabilities: EditAndContinueCapabilities.AddMethodToExistingType | EditAndContinueCapabilities.AddInstanceFieldToExistingType);
     }
@@ -19301,12 +19307,7 @@ public void Property_Partial_DeleteBoth()
         EditAndContinueValidation.VerifySemantics(
             [GetTopEdits(srcA1, srcA2), GetTopEdits(srcB1, srcB2)],
             [
-                DocumentResults(
-                    semanticEdits:
-                    [
-                        SemanticEdit(SemanticEditKind.Delete, c => c.GetMember<IPropertySymbol>("C.P").PartialImplementationPart, deletedSymbolContainerProvider: c => c.GetMember("C"), partialType: "C"),
-                        SemanticEdit(SemanticEditKind.Delete, c => c.GetMember<IMethodSymbol>("C.get_P").PartialImplementationPart, deletedSymbolContainerProvider: c => c.GetMember("C"), partialType: "C")
-                    ]),
+                DocumentResults(),
                 DocumentResults(
                     semanticEdits:
                     [

src/Features/Core/Portable/EditAndContinue/AbstractEditAndContinueAnalyzer.cs

@@ -2721,8 +2721,8 @@ newSymbol is IPropertySymbol newProperty &&
                                 }
 
                                 // If a partial method/property/indexer definition is deleted (and not moved to another partial type declaration, which is handled above)
-                                // so must be the implementation. An edit will be issued for the implementation change.
-                                if (newSymbol?.IsPartialDefinition() == true)
+                                // so must be the implementation (if it exists). An edit will be issued for the implementation change.
+                                if (oldSymbol.IsPartialDefinition())
                                 {
                                     continue;
                                 }

src/Features/VisualBasicTest/EditAndContinue/TopLevelEditingTests.vb

@@ -6029,11 +6029,7 @@ End Interface
             EditAndContinueValidation.VerifySemantics(
                 {GetTopEdits(srcA1, srcA2), GetTopEdits(srcB1, srcB2)},
                 {
-                    DocumentResults(
-                        semanticEdits:=
-                        {
-                            SemanticEdit(SemanticEditKind.Delete, Function(c) c.GetMember(Of MethodSymbol)("C.F").PartialImplementationPart, deletedSymbolContainerProvider:=Function(c) c.GetMember("C"), partialType:="C")
-                        }),
+                    DocumentResults(),
                     DocumentResults(
                         semanticEdits:=
                         {