blerg.coffee

window.app = format: {}

app.format.DollarizesCents = ->
  dollarize: (pennies) ->
    amount = (pennies / 100.0).toFixed(2)
    [dollars, cents] = amount.toString().split(".")
    "$#{@commasFor(dollars)}.#{cents}"

  #private
  commasFor: (dollars) ->
    s = ""
    while dollars.length > 3
      s = ",#{dollars.slice(-3)}#{s}"
      dollars = dollars.substring(0, dollars.length - 3)
    "#{dollars}#{s}"

blerg_spec.coffee

describe "app.format.DollarizesCents", ->
  Given -> @subject = app.format.DollarizesCents()
  
  describe "#dollarize", ->
    context "0 cents", ->
      Then -> @subject.dollarize(0) == "$0.00"

    context "50 cents", ->
      Then -> @subject.dollarize(50) == "$0.50"

    context "1,841,482 cents", ->
      Then -> @subject.dollarize(1841482) == "$18,414.82"

    context "213,981,400 cents", ->
      Then -> @subject.dollarize(213981400) == "$2,139,814.00"