Minor code refactoring

Author: Sergio0694

CommunityToolkit.Mvvm.SourceGenerators/ComponentModel/ObservablePropertyGenerator.cs

@@ -76,7 +76,6 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
         // Split and group by containing type
         IncrementalValuesProvider<(HierarchyInfo Hierarchy, ImmutableArray<PropertyInfo> Properties)> groupedPropertyInfo =
             propertyInfo
-            .Collect()
             .GroupBy(HierarchyInfo.Comparer.Default)
             .WithComparers(HierarchyInfo.Comparer.Default, PropertyInfo.Comparer.Default.ForImmutableArray());
 

CommunityToolkit.Mvvm.SourceGenerators/Extensions/IncrementalValueProviderExtensions.cs

@@ -7,6 +7,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using Microsoft.CodeAnalysis;
 
 namespace CommunityToolkit.Mvvm.SourceGenerators.Extensions;
@@ -16,6 +17,46 @@ namespace CommunityToolkit.Mvvm.SourceGenerators.Extensions;
 /// </summary>
 internal static class IncrementalValuesProviderExtensions
 {
+    /// <summary>
+    /// Groups items in a given <see cref="IncrementalValuesProvider{TValue}"/> sequence by a specified key.
+    /// </summary>
+    /// <typeparam name="TLeft">The type of left items in each tuple.</typeparam>
+    /// <typeparam name="TRight">The type of right items in each tuple.</typeparam>
+    /// <param name="source">The input <see cref="IncrementalValuesProvider{TValues}"/> instance.</param>
+    /// <param name="comparer">A <typeparamref name="TLeft"/> comparer.</param>
+    /// <returns>An <see cref="IncrementalValuesProvider{TValues}"/> with the grouped results.</returns>
+    public static IncrementalValuesProvider<(TLeft Left, ImmutableArray<TRight> Right)> GroupBy<TLeft, TRight>(
+        this IncrementalValuesProvider<(TLeft Left, TRight Right)> source,
+        IEqualityComparer<TLeft> comparer)
+    {
+        return source.Collect().SelectMany((item, _) =>
+        {
+            Dictionary<TLeft, ImmutableArray<TRight>.Builder> map = new(comparer);
+
+            foreach ((TLeft hierarchy, TRight info) in item)
+            {
+                if (!map.TryGetValue(hierarchy, out ImmutableArray<TRight>.Builder builder))
+                {
+                    builder = ImmutableArray.CreateBuilder<TRight>();
+
+                    map.Add(hierarchy, builder);
+                }
+
+                builder.Add(info);
+            }
+
+            ImmutableArray<(TLeft Hierarchy, ImmutableArray<TRight> Properties)>.Builder result =
+                ImmutableArray.CreateBuilder<(TLeft, ImmutableArray<TRight>)>();
+
+            foreach (KeyValuePair<TLeft, ImmutableArray<TRight>.Builder> entry in map)
+            {
+                result.Add((entry.Key, entry.Value.ToImmutable()));
+            }
+
+            return result;
+        });
+    }
+
     /// <summary>
     /// Creates a new <see cref="IncrementalValuesProvider{TValues}"/> instance with a gven pair of comparers.
     /// </summary>