Add arternative extension method for WithIndex

Author: I-RzR-I

src/DomainCommonExtensions/ArraysExtensions/EnumerableExtensions.cs

@@ -17,6 +17,7 @@
 using DomainCommonExtensions.CommonExtensions;
 using DomainCommonExtensions.CommonExtensions.TypeParam;
 using DomainCommonExtensions.DataTypeExtensions;
+using DomainCommonExtensions.Models;
 using System;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
@@ -344,6 +345,23 @@ public static bool IsNullOrEmptyEnumerable<T>(this IEnumerable<T> source)
         }
 #endif
 
+        /// <summary>
+        ///     Format list to list with item index
+        /// </summary>
+        /// <param name="self">Input list</param>
+        /// <returns></returns>
+        /// <typeparam name="T">List type</typeparam>
+        /// <remarks></remarks>
+        public static IEnumerable<WithIndexModel<T>> WithIndexModel<T>(this IEnumerable<T> self)
+        {
+            return self?.Select(
+                (item, index) => new WithIndexModel<T>()
+                {
+                    Index = index,
+                    Item = item
+                }) ?? new List<WithIndexModel<T>>();
+        }
+
         /// <summary>
         ///     Generates a string from a list of values with the given delimiter
         /// </summary>

src/DomainCommonExtensions/Models/WithIndexModel.cs

@@ -0,0 +1,47 @@
+// ***********************************************************************
+//  Assembly         : RzR.Shared.Extensions.DomainCommonExtensions
+//  Author           : RzR
+//  Created On       : 2025-07-15 18:33
+// 
+//  Last Modified By : RzR
+//  Last Modified On : 2025-07-15 18:33
+// ***********************************************************************
+//  <copyright file="WithIndexModel.cs" company="RzR SOFT & TECH">
+//   Copyright © RzR. All rights reserved.
+//  </copyright>
+// 
+//  <summary>
+//  </summary>
+// ***********************************************************************
+
+namespace DomainCommonExtensions.Models
+{
+    /// -------------------------------------------------------------------------------------------------
+    /// <summary>
+    ///     A data Model for the with index enumerable extension method.
+    /// </summary>
+    /// <typeparam name="T">Generic type parameter.</typeparam>
+    /// =================================================================================================
+    public struct WithIndexModel<T>
+    {
+        /// -------------------------------------------------------------------------------------------------
+        /// <summary>
+        ///     Gets or sets the zero-based index of this object.
+        /// </summary>
+        /// <value>
+        ///     The index.
+        /// </value>
+        /// =================================================================================================
+        public int Index { get; set; }
+
+        /// -------------------------------------------------------------------------------------------------
+        /// <summary>
+        ///     Gets or sets the item.
+        /// </summary>
+        /// <value>
+        ///     The item.
+        /// </value>
+        /// =================================================================================================
+        public T Item { get; set; }
+    }
+}

src/tests/DataTypeTests/DataTests/EnumerableTests.cs

@@ -14,7 +14,9 @@
 //  </summary>
 // ***********************************************************************
 
+using System.Collections.Generic;
 using System.Linq;
+using DataTypeTests.Models;
 using DomainCommonExtensions.ArraysExtensions;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
@@ -65,5 +67,105 @@ public void ChunkArray_Chunked_20_Test()
             Assert.AreEqual(1, chunks.Count());
             Assert.AreEqual(12, chunks[0].Count());
         }
+
+        [TestMethod]
+        public void WithIndex_Null_Test()
+        {
+            List<Models.IdNameActiveModel> array = null;
+
+            var arrayWithIndex = array.WithIndex();
+
+            Assert.IsNotNull(arrayWithIndex);
+            Assert.AreEqual(0, arrayWithIndex.Count());
+        }
+
+        [TestMethod]
+        public void WithIndex_Empty_Test()
+        {
+            var array = new List<Models.IdNameActiveModel>();
+
+            var arrayWithIndex = array.WithIndex();
+
+            Assert.IsNotNull(arrayWithIndex);
+            Assert.AreEqual(0, arrayWithIndex.Count());
+        }
+
+        [TestMethod]
+        public void WithIndex_Test()
+        {
+            var array = new List<Models.IdNameActiveModel>()
+            {
+                new IdNameActiveModel()
+                {
+                    Id = 0,
+                    Name = "Test 0",
+                    IsActive = true
+                },
+                new IdNameActiveModel()
+                {
+                    Id = 1,
+                    Name = "Test 1",
+                    IsActive = false
+                }
+            };
+
+            var arrayWithIndex = array.WithIndex();
+
+            Assert.IsNotNull(arrayWithIndex);
+            Assert.AreEqual(2, arrayWithIndex.Count());
+        }
+
+        [TestMethod]
+        public void WithIndexModel_Null_Test()
+        {
+            List<Models.IdNameActiveModel> array = null;
+
+            var arrayWithIndex = array.WithIndexModel();
+
+            Assert.IsNotNull(arrayWithIndex);
+            Assert.AreEqual(0, arrayWithIndex.Count());
+        }
+
+        [TestMethod]
+        public void WithIndexModel_Empty_Test()
+        {
+            var array = new List<Models.IdNameActiveModel>();
+
+            var arrayWithIndex = array.WithIndexModel();
+
+            Assert.IsNotNull(arrayWithIndex);
+            Assert.AreEqual(0, arrayWithIndex.Count());
+        }
+
+        [TestMethod]
+        public void WithIndexModel_Test()
+        {
+            var array = new List<Models.IdNameActiveModel>()
+            {
+                new IdNameActiveModel()
+                {
+                    Id = 0,
+                    Name = "Test 0",
+                    IsActive = true
+                },
+                new IdNameActiveModel()
+                {
+                    Id = 1,
+                    Name = "Test 1",
+                    IsActive = false
+                }
+            };
+
+            var arrayWithIndex = array.WithIndexModel();
+
+            Assert.IsNotNull(arrayWithIndex);
+            Assert.AreEqual(2, arrayWithIndex.Count());
+
+            var last = arrayWithIndex.Last();
+            Assert.IsNotNull(last);
+            Assert.IsNotNull(last.Item);
+            Assert.AreEqual(1, last.Item.Id);
+            Assert.AreEqual(1, last.Index);
+        }
     }
 }