CsvHelper PrepareHeaderForMatch returns Context as one-item array

Question

Been using CsvHelper version 6.0.0, decided to upgrade to latest (currently 12.3.2) and found out it uses another parameter, index in lambda for csv.Configuration.PrepareHeaderForMatch, (Func<string,int,string>).

The code for v6.0.0 looked like this:

csv.Configuration.PrepareHeaderForMatch = header => Regex.Replace(header, @"\/", string.Empty);

With previous line, the IReadingContext.Record returns an array with multiple records, one for each column.

The code for v12.3.2 looks like this:

csv.Configuration.PrepareHeaderForMatch = (header, index) => Regex.Replace(header, @"\/", string.Empty);

But ReadingContext.Record now returns an array with all columns in just one record. Used the exact same file for both versions. Tried messing with the lambda, but the outcome is the same. How can I get the columns in Records array?

Thanks in advance!

Answer 1

update - This is an issue with the delimiter that has changed since version 6.0.0. The default delimiter now uses CultureInfo.CurrentCulture.TextInfo.ListSeparator. Since I'm in the United States, my ListSeparator is , so both examples work for me. For many countries the ListSeparator is ; which is why for version 12.3.2 only 1 column was found for @dzookatz. The solution is to specify the delimiter in the configuration.

csv.Configuration.PrepareHeaderForMatch = header => Regex.Replace(header, @"\/", string.Empty);
csv.Configuration.Delimiter = ",";

---

I must be missing something. I get the same result for var record whether using version 6.0.0 or 12.3.2. I'm guessing there is more going on with your data that I'm not seeing.

Version 6.0.0

class Program
{
    static void Main(string[] args)
    {
        var fooString = $"Id,First/Name{Environment.NewLine}1,David";

        using (var reader = new StringReader(fooString))
        using (var csv = new CsvReader(reader))
        {
            csv.Configuration.PrepareHeaderForMatch = header => Regex.Replace(header, @"\/", string.Empty);

            csv.Read();
            csv.ReadHeader();

            while (csv.Read())
            {
                var record = csv.Context.Record;
            }
        }
    }
}

public class Foo
{
    public int Id { get; set; }
    public string FirstName { get; set; }
}

Version 12.3.2

public class Program
{
    public static void Main(string[] args)
    {
        var fooString = $"Id,First/Name{Environment.NewLine}1,David";

        using (var reader = new StringReader(fooString))
        using (var csv = new CsvReader(reader))
        {
            csv.Configuration.PrepareHeaderForMatch = (header, index) => Regex.Replace(header, @"\/", string.Empty);

            csv.Read();
            csv.ReadHeader();

            while (csv.Read())
            {
                var record = csv.Context.Record;
            }
        }
    }
}

public class Foo
{
    public int Id { get; set; }
    public string FirstName { get; set; }
}