Added Collection Extensions, Updated DateTimeExtensions

AMWD.Common/Extensions/CollectionExtensions.cs

@@ -0,0 +1,55 @@
+namespace System.Collections.Generic
+{
+	/// <summary>
+	/// Provides extension methods for generic <see cref="ICollection{T}"/> implementations.
+	/// </summary>
+	public static class CollectionExtensions
+	{
+		/// <summary>
+		/// Add the <paramref name="item"/> to the <paramref name="collection"/> if it is not <see langword="null"/>.
+		/// </summary>
+		/// <typeparam name="T">The type of the elements in the collection</typeparam>
+		/// <param name="collection">The collection.</param>
+		/// <param name="item">The item to add if not <see langword="null"/>.</param>
+		public static void AddIfNotNull<T>(this ICollection<T> collection, T item)
+		{
+#if NET8_0_OR_GREATER
+			ArgumentNullException.ThrowIfNull(collection);
+#else
+			if (collection == null)
+				throw new ArgumentNullException(nameof(collection));
+#endif
+
+			if (item == null)
+				return;
+
+			collection.Add(item);
+		}
+
+		/// <summary>
+		/// Adds a <see cref="AddRange{T}(ICollection{T}, IEnumerable{T})"/> functionallity to <see cref="ICollection{T}"/>.
+		/// </summary>
+		/// <typeparam name="T">The type of the elements in the collection.</typeparam>
+		/// <param name="collection">The collection.</param>
+		/// <param name="items">The items to add.</param>
+		public static void AddRange<T>(this ICollection<T> collection, IEnumerable<T> items)
+		{
+#if NET8_0_OR_GREATER
+			ArgumentNullException.ThrowIfNull(collection);
+			ArgumentNullException.ThrowIfNull(items);
+#else
+			if (collection == null)
+				throw new ArgumentNullException(nameof(collection));
+
+			if (items == null)
+				throw new ArgumentNullException(nameof(items));
+#endif
+
+			if (collection == items)
+				return;
+
+			foreach (var item in items)
+				collection.Add(item);
+		}
+	}
+}

AMWD.Common/Extensions/DateTimeExtensions.cs

@@ -61,20 +61,27 @@ namespace System
 		public static TimeSpan GetAlignedIntervalLocal(this TimeSpan timeSpan, TimeSpan offset = default)
 			=> timeSpan.GetAlignedInterval(DateTime.Now, offset);
 
-		internal static TimeSpan GetAlignedInterval(this TimeSpan timeSpan, DateTime now, TimeSpan offset = default)
+		/// <summary>
+		/// Aligns the <see cref="TimeSpan"/> to the specified time.
+		/// </summary>
+		/// <param name="timeSpan">The timespan to align.</param>
+		/// <param name="now">A timestamp to align with.</param>
+		/// <param name="offset">A specific offset to the timespan.</param>
+		/// <returns>The timespan until the aligned time.</returns>
+		public static TimeSpan GetAlignedInterval(this TimeSpan timeSpan, DateTime now, TimeSpan offset = default)
 		{
-			var nowWithOffset = new DateTimeOffset(now);
+			var dtOffsetNow = new DateTimeOffset(now);
 
-			var nextTime = new DateTime(nowWithOffset.Ticks / timeSpan.Ticks * timeSpan.Ticks, now.Kind).Add(offset);
-			var nextTimeWithOffset = new DateTimeOffset(nextTime);
+			var nextTime = new DateTime(dtOffsetNow.Ticks / timeSpan.Ticks * timeSpan.Ticks, now.Kind).Add(offset);
+			var dtOffsetNext = new DateTimeOffset(nextTime);
 
-			if (nextTimeWithOffset <= nowWithOffset)
-				nextTimeWithOffset = nextTimeWithOffset.Add(timeSpan);
+			if (dtOffsetNext <= dtOffsetNow)
+				dtOffsetNext = dtOffsetNext.Add(timeSpan);
 
 			if (now.Kind == DateTimeKind.Local)
-				return nextTimeWithOffset.LocalDateTime - nowWithOffset.LocalDateTime;
+				return dtOffsetNext.LocalDateTime - dtOffsetNow.LocalDateTime;
 
-			return nextTimeWithOffset - nowWithOffset;
+			return dtOffsetNext - dtOffsetNow;
 		}
 
 		#endregion Aligned Interval