It generates a duplicated ] symbol following rows equal last row. It gets solved by changing line 49 for:
@data.each_with_index do |row,i|
and line 63 for:
ds += i == @data.size - 1 ? "]" : ","
I believe someone else has already fixed this same issue for me recently. I've pulled in their changes earlier today. Try using the latest revision now.
It generates a duplicated ] symbol following rows equal last row. It gets solved by changing line 49 for: @data.each_with_index do |row,i| and line 63 for: ds += i == @data.size - 1 ? "]" : ","