VB -> C#: IEnumerable linq extension methods are replaced with static Enumerable methods

Inizia con l'input VB.NET e confronta l'output C# generato, concentrandoti sulle catene LINQ seguite da Sum, Max, Count e Zip. Traccia il percorso di conversione per questi metodi di estensione; il lavoro è completato quando l'output preserva la sintassi delle chiamate di estensione e include tutti i parametri di tipo generico richiesti.

IEnumerable.Select is replaced with Enumerable.Select if predicate is empty. Same happens to .Zip() and .OrderBy() but not to .Where().

It seems to be depended on the extension method used afterwards, while .Sum() and .Max() cause this bug, .Count() does not.

Tested with different numeric types, resulting in the same issue.

Also one generic type parameter is missing from the methods so it does not compile, e.g. .Select needs two but only has one or .Zip needs three but only has two.

VB.Net input code

    Public Class TestClass
        Public Shared Sub Test()
            Dim intCol = New Integer() {1, 2, 3}
            Dim intCol2 = New Integer() {1, 2, 3}

            Dim intColQuery = intCol.Select(Function(x) x)
            Dim intColCopy = intCol.Select(Function(x) x).ToArray()
            Dim intSum = intCol.Select(Function(x) x).Sum(Function(x) x)
            Dim intMax = intCol.Select(Function(x) x).Max(Function(x) x)
            Dim intCnt = intCol.Select(Function(x) x).Count(Function(x) x > 1)

            Dim intSum2 = intCol.Select(Function(x) x).Sum()
            Dim intMax2 = intCol.OrderBy(Function(x) x).Max()
            Dim intCnt2 = intCol.Select(Function(x) x).Count()
            Dim intSum3 = intCol.Zip(intCol2, Function(x, y) x + y).Sum()
        End Sub
    End Class

Erroneous output

public class TestClass
{
    public static void Test()
    {
        int[] intCol = new int[] { 1, 2, 3 };
        int[] intCol2 = new int[] { 1, 2, 3 };

        var intColQuery = intCol.Select(x => x);
        int[] intColCopy = intCol.Select(x => x).ToArray();
        int intSum = intCol.Select(x => x).Sum(x => x);
        int intMax = intCol.Select(x => x).Max(x => x);
        int intCnt = intCol.Select(x => x).Count(x => x > 1);

        var intSum2 = Enumerable.Select<int>((IEnumerable<int>)intCol, x => x).Sum();
        var intMax2 = Enumerable.OrderBy<int>((IEnumerable<int>)intCol, x => x).Max();
        int intCnt2 = intCol.Select(x => x).Count();
        var intSum3 = Enumerable.Zip<int, int>((IEnumerable<int>)intCol, (IEnumerable<int>)intCol2, (x, y) => x + y).Sum();
    }
}

Expected output

    public class TestClass
    {
        public static void Test()
        {
            int[] intCol = new int[] { 1, 2, 3 };
            int[] intCol2 = new int[] { 1, 2, 3 };

            var intColQuery = intCol.Select(x => x);
            int[] intColCopy = intCol.Select(x => x).ToArray();
            int intSum = intCol.Select(x => x).Sum(x => x);
            int intMax = intCol.Select(x => x).Max(x => x);
            int intCnt = intCol.Select(x => x).Count(x => x > 1);

            int intSum2 = intCol.Select(x => x).Sum();
            int intMax2 = intCol.OrderBy(x => x).Max();
            int intCnt2 = intCol.Select(x => x).Count();
            int intSum3 = intCol.Zip(intCol2, (x, y) => x + y).Sum();
        }
    }

Details

• Product in use: VS extension
• Version in use: 9.2.6.0