Provides object extensions Map and Tap. Like LINQ Select, but for non-collections. int.Parse("5") becomes "5".Map(int.Parse).

MappingExtensions.cs

    public static class MappingExtensions
    {
        /// <summary>
        /// Applies the specified <paramref name="transformation"/> on the <paramref name="source"/>.
        /// </summary>
        /// <typeparam name="TSource"></typeparam>
        /// <typeparam name="T"></typeparam>
        /// <param name="source"></param>
        /// <param name="transformation"></param>
        /// <returns></returns>
        public static T Map<TSource, T>(this TSource source, Func<TSource, T> transformation)
        {
            if (transformation == null)
            {
                throw new ArgumentNullException(nameof(transformation));
            }

            return transformation(source);
        }

        /// <summary>
        /// Applies the specified <paramref name="transformation"/> on the <paramref name="source"/> task result.
        /// </summary>
        /// <typeparam name="TSource"></typeparam>
        /// <typeparam name="T"></typeparam>
        /// <param name="source"></param>
        /// <param name="transformation"></param>
        /// <returns></returns>
        public static async Task<T> Map<TSource, T>(this Task<TSource> source, Func<TSource, T> transformation)
        {
            var sourceResult = await source;
            return sourceResult.Map(transformation);
        }

        /// <summary>
        /// Applies the specified <paramref name="action"/> on the <paramref name="source"/>.
        /// </summary>
        /// <typeparam name="TSource"></typeparam>
        /// <param name="source"></param>
        /// <param name="action"></param>
        /// <returns></returns>
        public static TSource Tap<TSource>(this TSource source, Action<TSource> action)
        {
            if (action == null)
            {
                throw new ArgumentNullException(nameof(action));
            }

            action(source);

            return source;
        }

        /// <summary>
        /// Applies the specified <paramref name="action"/> on the <paramref name="source"/> task result.
        /// </summary>
        /// <typeparam name="TSource"></typeparam>
        /// <param name="source"></param>
        /// <param name="action"></param>
        /// <returns></returns>
        public static async Task<TSource> Tap<TSource>(this Task<TSource> source, Action<TSource> action)
        {
            var sourceResult = await source;
            return sourceResult.Tap(action);
        }
    }