System.Linq.Tests.SelectTests.Select_SourceIsIEnumerable_ReturnsExpectedValues C# (CSharp) Method

        public void Select_SourceIsIEnumerable_ReturnsExpectedValues()
        {
            int nbOfItems = 5;
            IEnumerable<int> source = Enumerable.Range(1, nbOfItems);
            Func<int, int> selector = i => i + 1;

            IEnumerable<int> query = source.Select(selector);

            int index = 0;
            foreach (var item in query)
            {
                index++;
                var expected = selector(index);
                Assert.Equal(expected, item);
            }

            Assert.Equal(nbOfItems, index);
        }