Add invocation of partial generated methods

Author: Sergio0694

CommunityToolkit.Mvvm.SourceGenerators/ComponentModel/ObservablePropertyGenerator.Execute.cs

@@ -146,6 +146,14 @@ public static MemberDeclarationSyntax GetPropertySyntax(PropertyInfo propertyInf
         {
             ImmutableArray<StatementSyntax>.Builder setterStatements = ImmutableArray.CreateBuilder<StatementSyntax>();
 
+            // Add the OnPropertyChanging() call first:
+            //
+            // On<PROPERTY_NAME>Changing(value);
+            setterStatements.Add(
+                ExpressionStatement(
+                    InvocationExpression(IdentifierName($"On{propertyInfo.PropertyName}Changing"))
+                    .AddArgumentListArguments(Argument(IdentifierName("value")))));
+
             // Gather the statements to notify dependent properties
             foreach (string propertyName in propertyInfo.PropertyChangingNames)
             {
@@ -192,6 +200,14 @@ public static MemberDeclarationSyntax GetPropertySyntax(PropertyInfo propertyInf
                             Argument(LiteralExpression(SyntaxKind.StringLiteralExpression, Literal(propertyInfo.PropertyName))))));
             }
 
+            // Add the OnPropertyChanged() call:
+            //
+            // On<PROPERTY_NAME>Changed(value);
+            setterStatements.Add(
+                ExpressionStatement(
+                    InvocationExpression(IdentifierName($"On{propertyInfo.PropertyName}Changed"))
+                    .AddArgumentListArguments(Argument(IdentifierName("value")))));
+
             // Gather the statements to notify dependent properties
             foreach (string propertyName in propertyInfo.PropertyChangedNames)
             {