module ActiveSupport module NumberHelper class RoundingHelper # :nodoc: attr_reader :options def initialize(options) @options = options end def round(number) return number unless precision number = convert_to_decimal(number) if significant && precision > 0 round_significant(number) else round_without_significant(number) end end def digit_count(number) return 1 if number.zero? (Math.log10(absolute_number(number)) + 1).floor end private def round_without_significant(number) number = number.round(precision) number = number.to_i if precision == 0 && number.finite? number = number.abs if number.zero? # prevent showing negative zeros number end def round_significant(number) return 0 if number.zero? digits = digit_count(number) multiplier = 10**(digits - precision) (number / BigDecimal.new(multiplier.to_f.to_s)).round * multiplier end def convert_to_decimal(number) case number when Float, String BigDecimal(number.to_s) when Rational BigDecimal(number, digit_count(number.to_i) + precision) else number.to_d end end def precision options[:precision] end def significant options[:significant] end def absolute_number(number) number.respond_to?(:abs) ? number.abs : number.to_d.abs end end end end