Add GetValueOrNull on IDictionary<,> and IReadOnlyDictionary<,> for struct values

PowerKit.Tests/Extensions/DictionaryExtensionsTests.cs

@@ -9,6 +9,17 @@ namespace PowerKit.Tests.Extensions;
 
 public class DictionaryExtensionsTests
 {
+    [Fact]
+    public void GetValueOrNull_Test()
+    {
+        // Arrange
+        var source = (IDictionary<string, int>)new Dictionary<string, int> { ["one"] = 1 };
+
+        // Act & assert
+        source.GetValueOrNull("one").Should().Be(1);
+        source.GetValueOrNull("two").Should().BeNull();
+    }
+
     [Fact]
     public void ToDictionary_Test()
     {

PowerKit.Tests/Extensions/ReadOnlyDictionaryExtensionsTests.cs

@@ -0,0 +1,20 @@
+using System.Collections.Generic;
+using FluentAssertions;
+using PowerKit.Extensions;
+using Xunit;
+
+namespace PowerKit.Tests.Extensions;
+
+public class ReadOnlyDictionaryExtensionsTests
+{
+    [Fact]
+    public void GetValueOrNull_Test()
+    {
+        // Arrange
+        var source = (IReadOnlyDictionary<string, int>)new Dictionary<string, int> { ["one"] = 1 };
+
+        // Act & assert
+        source.GetValueOrNull("one").Should().Be(1);
+        source.GetValueOrNull("two").Should().BeNull();
+    }
+}

PowerKit/Extensions/DictionaryExtensions.cs

@@ -11,6 +11,17 @@ namespace PowerKit.Extensions;
 #endif
 internal static class DictionaryExtensions
 {
+    extension<TKey, TValue>(IDictionary<TKey, TValue> dictionary)
+        where TKey : notnull
+        where TValue : struct
+    {
+        /// <summary>
+        /// Returns the value associated with the specified key, or <see langword="null" /> if the key is not found.
+        /// </summary>
+        public TValue? GetValueOrNull(TKey key) =>
+            dictionary.TryGetValue(key, out var value) ? value : null;
+    }
+
     extension(IDictionary dictionary)
     {
         /// <summary>

PowerKit/Extensions/ReadOnlyDictionaryExtensions.cs

@@ -0,0 +1,24 @@
+#nullable enable
+#if NET40_OR_GREATER || NETSTANDARD || NET
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+
+namespace PowerKit.Extensions;
+
+#if !POWERKIT_INCLUDE_COVERAGE
+[ExcludeFromCodeCoverage]
+#endif
+internal static class ReadOnlyDictionaryExtensions
+{
+    extension<TKey, TValue>(IReadOnlyDictionary<TKey, TValue> dictionary)
+        where TKey : notnull
+        where TValue : struct
+    {
+        /// <summary>
+        /// Returns the value associated with the specified key, or <see langword="null" /> if the key is not found.
+        /// </summary>
+        public TValue? GetValueOrNull(TKey key) =>
+            dictionary.TryGetValue(key, out var value) ? value : null;
+    }
+}
+#endif