BeWoPlaner/Shared/Extensions/ICollectionExtensions.cs

using System;
using System.Collections.Generic;
using System.Linq;

namespace BS.Shared.Extensions
{
	public static class ICollectionExtensions
	{
		public static void AddIfNotIn<T>(this ICollection<T> pCollection, T pToAdd)
		{
			if (!pCollection.Contains(pToAdd))
			{
				pCollection.Add(pToAdd);
			}
		}

		public static void AddRange<T>(this ICollection<T> pCollection, IEnumerable<T> pToAdd)
		{
			foreach (var iItem in pToAdd)
			{
				pCollection.Add(iItem);
			}
		}

		public static bool Exists<T>(this IEnumerable<T> pCollection, Predicate<T> pMatch)
		{
			return pCollection.Any(iItem => pMatch(iItem));
		}

		public static void RemoveRange<T>(this ICollection<T> pList, IEnumerable<T> pToRemove)
		{
			foreach (T iItem in pToRemove.ToList())
			{
				pList.Remove(iItem);
			}
		}

		public static void RemoveRange<T>(this ICollection<T> pList, Predicate<T> pMatch)
		{
			var lToDelete = pList.Where(t => pMatch(t)).ToHashSet();
			pList.RemoveRange(lToDelete);
		}

        public static bool AreEqual<T>(this ICollection<T> pCollection, ICollection<T> pCollection2)
        {
			if(pCollection.Count != pCollection2.Count)
			{
				return false;
			}

			var tmp1 = pCollection.OrderBy(x => x.GetHashCode()).ToList();
			var tmp2 = pCollection2.OrderBy(x => x.GetHashCode()).ToList();

			return !pCollection.Where((t, i) => !tmp1.ElementAt(i).Equals(tmp2.ElementAt(i))).Any();
		}

        public static bool ListEquals<T>(ICollection<T> list1, ICollection<T> list2)
        {
            if(list1 is null && list2 is null)
            {
                return true;
            }

            if(list1 is null || list2 is null)
            {
                return false;
            }

            return list1.Count == list2.Count && list1.All(list2.Contains);
        }
	}
}