Module: SplitBetween

Included in:
Money
Defined in:
lib/money_extensions/split_between.rb

Instance Method Summary collapse

Instance Method Details

#/(*_params) ⇒ Object

Override division – should not do it, but use split_between



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# File 'lib/money_extensions/split_between.rb', line 5

def /(*_params)
  raise "Division of money NOT allowed - use 'split_between' to avoid rounding errors"
end

#split_between(params) ⇒ Object

Split the money between the specified number - and return an array of money Remainder in splits are given to the highest value e.g. $2.00 splits [40, 81, 40] into [49, 102, 49] $1.01 splits [ 1, 1, 1] into [35, 33, 33]



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# File 'lib/money_extensions/split_between.rb', line 13

def split_between(params)
  # if just a number is passed in, then money is split equally
  if params.is_a?(Integer)
    divisor = params
    raise ArgumentError, 'Can only split up over a positive number' if divisor < 1

    rounded_split = lossy_divide(divisor)
    results       = Array.new(divisor, rounded_split) # Create with 'divisor' num elements

    # if an array of monies is passed in, then split in proportions
  elsif params.is_a?(Array)

    raise ArgumentError, 'Can only split up over at least one ration' if params.empty? && !zero?

    results = params.map { |p| p.is_a?(::Money) ? p.cents : p }

    total = results.inject(:+)
    if total.zero?
      return Array.new(results.size, ::Money.new(0)) if zero?

      raise ArgumentError, "Total of ratios should not be zero! You sent in: #{params.inspect}"
    end

    results.map! do |ratio|
      ::Money.new((cents * (ratio.to_f / total)).round)
    end
  else
    raise 'Either a Integer or array has to be passed in for splitting money'
  end

  # Distribute rounding to max absolute to avoid a $0 amount getting the rounding
  biggest_value_index = results.index(results.max_by(&:abs))
  results[biggest_value_index] += self - results.total_money

  results
end