String.format coffeescript version

string.format.coffee

  @format = ->
    return unless arguments.length

    str = arguments[0]

    for i in [1...arguments.length]
      re = new RegExp('\\{' + (i-1) + '\\}', 'gm')
      str = str.replace(re, arguments[i])
    str

string.format.spec.coffee

describe "@format", ->
  it "format normal", ->
    expect(@format("def")).toEqual("def")

  it "format normal", ->
    expect(@format("def{0}{1}", "def", "def2")).toEqual("defdefdef2")