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cashrb

Dead simple gem to work with Money/Currency without the hassle of Floats.

Usage

require 'cashrb'

# Works with cents to avoid Floating point errors
n = Cash.new(100)
n.cents #=> 100
n.to_s  #=> "1.00"
n.to_f  #=> 1.0

# Define currency as you see fit.
a = Cash.new(100, currency: :usd)
b = Cash.new(100, currency: :eur)
a + b #=> Error! Cash::IncompatibleCurrency

# Default is 100 cents in a dollar. Is your currency different, then just
# tell it.
n = Cash.new(100, cents_in_dollar: 5)
n.cents #=> 100
n.to_s  #=> "20.0"
n.to_f  #=> 20.0

n = Cash.new(100, cents_in_dollar: 10)
n.cents #=> 100
n.to_s  #=> "10.0"
n.to_f  #=> 10.0

n = Cash.new(100, cents_in_dollar: 1)
n.cents #=> 100
n.to_s  #=> "100"
n.to_f  #=> 100.0

# The default rounding method when dealing with fractional cents is
# BigDecimal::ROUND_HALF_UP. Would you rather use bankers rounding; just
# pass it as an argument.
n = Cash.new(2.5)
n.cents #=> 3

n = Cash.new(2.5, rounding_method: BigDecimal::ROUND_HALF_EVEN)
n.cents #=> 2

# Sick of specifying :cents_in_whole, :rounding_method and :currency; just
# set their defaults.
Cash.default_cents_in_whole  = 10
Cash.default_rounding_method = BigDecimal::ROUND_DOWN
Cash.default_currency        = :EUR

n = Cash.new(100)
n.to_s     #=> "10.0"
n.to_f     #=> 10.0
n.currency #=> :EUR

n = Cash.new(1.9)
n.cents #=> 1

# If your currency object implements :cents_in_whole, we'll go ahead and
# use that.

module MyCurrency
  def self.cents_in_whole
    10
  end
end

n = Cash.new(9, :currency => MyCurrency)
n.to_f #=> 0.9