UnitPartsConverterSource.cs

    public class UnitPartsConverterSource : IEnumerable
    {
        public static SiUnit Metres = new SiUnit("", "Metres", "m");

        public static SiUnit Kilograms = new SiUnit("", "Kilograms", "kg");

        public static SiUnit Seconds = new SiUnit("", "Seconds", "s");

        private List<Data> _datas = new List<Data>
                                        {
                                            new Data("m^2", new UnitAndPower(Metres, 2)),
                                            new Data("kg*m/s^2",new UnitAndPower(Kilograms, 1),new UnitAndPower(Metres, 1),new UnitAndPower(Seconds, -2)),
                                        };
        public IEnumerator GetEnumerator()
        {
            return _datas.GetEnumerator();
        }
        public class Data
        {
            public Data(string value, params UnitAndPower[] units)
            {
                this.Value = value;
                this.Units = units;
            }
            public string Value { get; set; }
            public IEnumerable<UnitAndPower> Units { get; private set; }
        }
    }

UnitPartsConverterTests.cs

    public class UnitPartsConverterTests
    {
        [TestCaseSource(typeof(UnitPartsConverterSource))]
        public void ConvertFrom(UnitPartsConverterSource.Data data)
        {
            var converter = new UnitPartsConverter();
            Assert.IsTrue(converter.CanConvertFrom(null, typeof(string)));
            var parts = (UnitParts)converter.ConvertFrom(null, null, data.Value);
            CollectionAssert.AreEquivalent(data.Units, parts);
        }
    }