module Sprockets::SourceMapUtils

def decode_vlq_mappings(str, sources: [], names: [])
  mappings = []
  source_id       = 0
  original_line   = 1
  original_column = 0
  name_id         = 0
  vlq_decode_mappings(str).each_with_index do |group, index|
    generated_column = 0
    generated_line   = index + 1
    group.each do |segment|
      generated_column += segment[0]
      generated = [generated_line, generated_column]
      if segment.size >= 4
        source_id        += segment[1]
        original_line    += segment[2]
        original_column  += segment[3]
        source   = sources[source_id]
        original = [original_line, original_column]
      else
        # TODO: Research this case
        next
      end
      if segment[4]
        name_id += segment[4]
        name     = names[name_id]
      end
      mapping = {source: source, generated: generated, original: original}
      mapping[:name] = name if name
      mappings << mapping
    end
  end
  mappings
end