Enum to enum / string to enum mapper

EnumMapper.cs

using System;

public static class EnumMapper
    {
        public static TEnum MapToEnum<TEnum>(this Enum originalEnumValue, bool ignoreCase = true) where TEnum : struct, IConvertible
        {
            if (!typeof(TEnum).IsEnum)
            {
                throw new ArgumentException("TEnum must be an enumerated type");
            }
            
            var parsed = Enum.TryParse(originalEnumValue.ToString(), ignoreCase, out TEnum result);

            if (parsed)
                return result;

            throw new ArgumentOutOfRangeException(nameof(originalEnumValue), $"Value {originalEnumValue} of enum type {originalEnumValue.GetType().Name} could not be mapped to {typeof(TEnum).Name} enum.");
        }

        public static TEnum MapToEnum<TEnum>(this string originalEnumValue, bool ignoreCase = true) where TEnum : struct, IConvertible
        {
            if (!typeof(TEnum).IsEnum)
            {
                throw new ArgumentException("TEnum must be an enumerated type");
            }

            var parsed = Enum.TryParse(originalEnumValue, ignoreCase, out TEnum result);

            if (parsed)
                return result;

            throw new ArgumentOutOfRangeException(nameof(originalEnumValue), $"Value {originalEnumValue} of enum type {originalEnumValue.GetType().Name} could not be mapped to {typeof(TEnum).Name} enum.");
        }
    }
    
using System;

using FluentAssertions;

using Xunit;

     public class EnumMapperTests
    {
        private enum DayOfWeekCustom
        {
            Friday,
            Funday,
            SUNDAY
        }

        [Fact]
        public void MapToEnum_WhenMatchExists_ShouldReturnMatchingValue()
        {
            var original = DayOfWeekCustom.Friday;

            var result = original.MapToEnum<DayOfWeek>();

            result.Should().Be(DayOfWeek.Friday);
        }

        [Fact]
        public void MapToEnum_FromString_WhenMatchExists_ShouldReturnMatchingValue()
        {
            var original = "Friday";

            var result = original.MapToEnum<DayOfWeek>();

            result.Should().Be(DayOfWeek.Friday);
        }

        [Fact]
        public void MapToEnum_Default_ShouldBeCaseInsensitive()
        {
            var original = DayOfWeekCustom.SUNDAY;

            var result = original.MapToEnum<DayOfWeek>();

            result.Should().Be(DayOfWeek.Sunday);
        }

        [Fact]
        public void MapToEnum_FromString_Default_ShouldBeCaseInsensitive()
        {
            var original = "SUNDAY";

            var result = original.MapToEnum<DayOfWeek>();

            result.Should().Be(DayOfWeek.Sunday);
        }

        [Fact]
        public void MapToEnum_WhenMatchDoesNotExist_ThrowsArgumentOutOfRangeException()
        {
            var original = DayOfWeekCustom.Funday;

            Action mapAction = () => original.MapToEnum<DayOfWeek>();

            mapAction.Should().Throw<ArgumentOutOfRangeException>();
        }

        [Fact]
        public void MapToEnum_FromString_WhenMatchDoesNotExist_ThrowsArgumentOutOfRangeException()
        {
            var original = "Funday";

            Action mapAction = () => original.MapToEnum<DayOfWeek>();

            mapAction.Should().Throw<ArgumentOutOfRangeException>();
        }

        [Fact]
        public void MapToEnum_WhenMadeCaseSensitive_ThrowsArgumentOutOfRangeExceptionOnFailedMatch()
        {
            var original = DayOfWeekCustom.SUNDAY;

            Action mapAction = () => original.MapToEnum<DayOfWeek>(ignoreCase: false);

            mapAction.Should().Throw<ArgumentOutOfRangeException>();
        }

        [Fact]
        public void MapToEnum_FromString_WhenMadeCaseSensitive_ThrowsArgumentOutOfRangeExceptionOnFailedMatch()
        {
            var original = "SUNDAY";

            Action mapAction = () => original.MapToEnum<DayOfWeek>(ignoreCase: false);

            mapAction.Should().Throw<ArgumentOutOfRangeException>();
        }
    }