Add ToDictionary extensions on IDictionary

PowerKit.Tests/DictionaryExtensionsTests.cs

@@ -0,0 +1,39 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using FluentAssertions;
+using PowerKit.Extensions;
+using Xunit;
+
+namespace PowerKit.Tests;
+
+public class DictionaryExtensionsTests
+{
+    [Fact]
+    public void ToDictionary_Test()
+    {
+        // Arrange
+        var source = (IDictionary)new Hashtable { ["one"] = 1, ["two"] = 2 };
+
+        // Act
+        var result = source.ToDictionary<string, int>();
+
+        // Assert
+        result.Should().BeOfType<Dictionary<string, int>>();
+        result.Should().Contain("one", 1).And.Contain("two", 2);
+    }
+
+    [Fact]
+    public void ToDictionary_CustomComparer_Test()
+    {
+        // Arrange
+        var source = (IDictionary)new Hashtable { ["one"] = 1, ["two"] = 2 };
+
+        // Act
+        var result = source.ToDictionary<string, int>(StringComparer.OrdinalIgnoreCase);
+
+        // Assert
+        result.Should().BeOfType<Dictionary<string, int>>();
+        result.Should().Contain("ONE", 1).And.Contain("TWO", 2);
+    }
+}

PowerKit/Extensions/DictionaryExtensions.cs

@@ -0,0 +1,32 @@
+#nullable enable
+using System.Collections;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.Linq;
+
+namespace PowerKit.Extensions;
+
+#if !POWERKIT_INCLUDE_COVERAGE
+[ExcludeFromCodeCoverage]
+#endif
+internal static class DictionaryExtensions
+{
+    extension(IDictionary dictionary)
+    {
+        /// <summary>
+        /// Converts a non-generic dictionary to a typed <see cref="Dictionary{TKey, TValue}"/> using the specified comparer.
+        /// </summary>
+        public Dictionary<TKey, TValue> ToDictionary<TKey, TValue>(IEqualityComparer<TKey> comparer)
+            where TKey : notnull =>
+            dictionary
+                .Cast<DictionaryEntry>()
+                .ToDictionary(entry => (TKey)entry.Key, entry => (TValue)entry.Value!, comparer);
+
+        /// <summary>
+        /// Converts a non-generic dictionary to a typed <see cref="Dictionary{TKey, TValue}"/> using the default comparer.
+        /// </summary>
+        public Dictionary<TKey, TValue> ToDictionary<TKey, TValue>()
+            where TKey : notnull =>
+            dictionary.ToDictionary<TKey, TValue>(EqualityComparer<TKey>.Default);
+    }
+}