System.Linq.Tests.WhereTests.Where_PredicateThrowsException C# (CSharp) Method

        public void Where_PredicateThrowsException()
        {
            int[] source = new[] { 1, 2, 3, 4, 5 };
            Func<int, bool> predicate = value =>
            {
                if (value == 1)
                {
                    throw new InvalidOperationException();
                }
                return true;
            };

            var enumerator = source.Where(predicate).GetEnumerator();

            // Ensure the first MoveNext call throws an exception
            Assert.Throws<InvalidOperationException>(() => enumerator.MoveNext());

            // Ensure Current is set to the default value of type T
            int currentValue = enumerator.Current;
            Assert.Equal(default(int), currentValue);

            // Ensure subsequent MoveNext calls succeed
            Assert.True(enumerator.MoveNext());
            Assert.Equal(2, enumerator.Current);
        }