Rename and enhance methods in EnumerableExtensions

Renamed `Random<TItem>` to `Shuffle<T>` and updated its implementation to use the Fisher-Yates shuffle algorithm. Added a new `Random<T>` method to retrieve a random element from an `IEnumerable<T>`. Updated method documentation and added `ArgumentNullException` checks. Updated `README.md` to reflect these changes. Added `System.Linq` namespace to support necessary extension methods.

README.md

@@ -200,12 +200,26 @@ DateTime? ToNullable(this DateTime value);
 
 ```csharp
 /// <summary>
-/// Randomizes the order of the elements in the collection.
+/// Shuffles the elements of the <see cref="IEnumerable{T}"/>.
 /// </summary>
-/// <typeparam name="TItem"> Type of the items in the collection. </typeparam>
-/// <param name="enumerable"> Collection to randomize. </param>
-/// <returns> Randomized collection. </returns>
-IEnumerable<TItem> Random<TItem>(this IEnumerable<TItem> enumerable);
+/// <typeparam name="T">The type of the elements in the <see cref="IEnumerable{T}"/>.</typeparam>
+/// <param name="source">The <see cref="IEnumerable{T}"/> to shuffle.</param>
+/// <returns>A shuffled <see cref="IEnumerable{T}"/>.</returns>
+/// <exception cref="ArgumentNullException">Thrown when <paramref name="source"/> is null.</exception>
+IEnumerable<T> Shuffle<T>(this IEnumerable<T> source);
+```
+
+---
+
+```csharp
+/// <summary>
+/// Gets a random element from the <see cref="IEnumerable{T}"/>.
+/// </summary>
+/// <typeparam name="T">The type of the elements in the <see cref="IEnumerable{T}"/>.</typeparam>
+/// <param name="enumerable">The <see cref="IEnumerable{T}"/> to get a random element from.</param>
+/// <returns>A random element from the <see cref="IEnumerable{T}"/>.</returns>
+/// <exception cref="ArgumentNullException">Thrown when <paramref name="enumerable"/> is null.</exception>
+T Random<T>(this IEnumerable<T> enumerable);
 ```
 
 

Sources/EasyExtensions/Extensions/EnumerableExtensions.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Linq;
 using System.Collections.Generic;
 
 namespace EasyExtensions
@@ -9,23 +10,40 @@ namespace EasyExtensions
     public static class EnumerableExtensions
     {
         /// <summary>
-        /// Randomizes the order of the elements in the collection.
+        /// Shuffles the elements of the <see cref="IEnumerable{T}"/>.
         /// </summary>
-        /// <typeparam name="TItem"> Type of the items in the collection. </typeparam>
-        /// <param name="enumerable"> Collection to randomize. </param>
-        /// <returns> Randomized collection. </returns>
-        public static IEnumerable<TItem> Random<TItem>(this IEnumerable<TItem> enumerable)
+        /// <typeparam name="T">The type of the elements in the <see cref="IEnumerable{T}"/>.</typeparam>
+        /// <param name="source">The <see cref="IEnumerable{T}"/> to shuffle.</param>
+        /// <returns>A shuffled <see cref="IEnumerable{T}"/>.</returns>
+        /// <exception cref="ArgumentNullException">Thrown when <paramref name="source"/> is null.</exception>
+        public static IEnumerable<T> Shuffle<T>(this IEnumerable<T> source)
         {
-            Random random = new Random();
-            List<TItem> list = new List<TItem>(enumerable);
-            int count = list.Count;
-            for (int i = 0; i < count; i++)
+            var random = new Random();
+            T[] elements = source.ToArray();
+            for (int i = elements.Length - 1; i >= 0; i--)
             {
-                int index = random.Next(count);
-                yield return list[index];
-                list.RemoveAt(index);
-                count--;
+                int swapIndex = random.Next(i + 1);
+                yield return elements[swapIndex];
+                elements[swapIndex] = elements[i];
             }
         }
+
+        /// <summary>
+        /// Gets a random element from the <see cref="IEnumerable{T}"/>.
+        /// </summary>
+        /// <typeparam name="T">The type of the elements in the <see cref="IEnumerable{T}"/>.</typeparam>
+        /// <param name="enumerable">The <see cref="IEnumerable{T}"/> to get a random element from.</param>
+        /// <returns>A random element from the <see cref="IEnumerable{T}"/>.</returns>
+        /// <exception cref="ArgumentNullException">Thrown when <paramref name="enumerable"/> is null.</exception>
+        public static T Random<T>(this IEnumerable<T> enumerable)
+        {
+            if (enumerable == null)
+            {
+                throw new ArgumentNullException(nameof(enumerable));
+            }
+            var random = new Random();
+            var list = enumerable as IList<T> ?? enumerable.ToList();
+            return list.Count == 0 ? default! : list[random.Next(0, list.Count)];
+        }
     }
 }