Multiplication table generator - after

1_week_3c_text_formatting.rb

# This method generates a multiplication table.

class Table
  def generate_table(
    table_size,
    title = '',
    decoration = ''
  )
    result = ''
    heading = "Times table to #{table_size}\n"
    table = multiplication_table(table_size)
    length = table.lines[-1].size
    border = decoration.to_s * (length) + "\n"

    result << heading if title == "title"
    result << border unless decorate? decoration
    result << table
    result << border unless decorate? decoration
    result
  end


  private

  def decorate?(decoration)
    [ :nil? , :empty?, :blank?].any? do |method_name|
      decoration.respond_to?(method_name) && decoration.send(method_name)
    end
  end

  def multiplication_table(table_size)
    table = ''
    1.upto(table_size) do |i|
      row = ''
      1.upto(table_size) do |j|
        row << build_row(table_size, [i, j])
      end
      table << row << "\n"
    end
    table
  end

  def build_row(table_size, multiplands)
    i, j = multiplands
    # i = numbers[0]
    # j = numbers[1]
    ' ' << spacing(product(i, j)[:length], spaces(table_size) + 1) <<
    product(i, j)[:value].to_s
  end

  def spaces(integer)
    integer.to_s.size
  end

  def product(i, j)
    { value: i * j, length: (i * j).to_s.length }
  end

  def spacing(num_size, col_size)
    num_size < col_size ? ' ' * (col_size - num_size) : ''
  end
end

## This is a pass / fail test.  To get get graded test just load it
## in irb and run or use the inspect method.
# doctest: Acceptance test & with no title but with decoration
# >> standard = "++++++++++\n  1  2  3\n  2  4  6\n  3  6  9\n++++++++++\n"
# >> Table.new().generate_table(3, "", "+") == standard
# => true
# doctest: Acceptance test with title and no decoration
# >> standard = "Times table to 3\n  1  2  3\n  2  4  6\n  3  6  9\n"
# >> Table.new().generate_table(3, "title") == standard
# => true
# doctest: Acceptance test with no decoration & no title
# >> standard = "  1  2  3\n  2  4  6\n  3  6  9\n"
# >> Table.new().generate_table(3, '', '') == standard
# => true
# doctest: Acceptance test with larger multiplands
# >> standard = "  1  2  3  4\n  2  4  6  8\n  3  6  9 12\n  4  8 12 16\n"
# >> Table.new().generate_table(4, '', '') == standard
# => true
# doctest: Acceptance test & with title and decoration
# >> standard ="Times table to 3\n++++++++++\n  1  2  3\n  2  4  6\n  3  6  9\n++++++++++\n"
# >> Table.new().generate_table(3, "title", "+") == standard
# => true