Object.assign

object-assign.coffee

assign = (target, firstSource) ->
    if !target?
        throw new TypeError('Cannot convert first argument to object')

    to = Object(target)
    hasPendingException = false
    pendingException = undefined
    i = 1
    while i < arguments.length
        nextSource = arguments[i]
        if !nextSource?
            i++
            continue
        keysArray = Object.keys Object(nextSource)
        nextIndex = 0
        len = keysArray.length
        while nextIndex < len
            nextKey = keysArray[nextIndex]
            try
                desc = Object.getOwnPropertyDescriptor(nextSource, nextKey)
                if desc != undefined and desc.enumerable
                    to[nextKey] = nextSource[nextKey]
            catch e
                if !hasPendingException
                    hasPendingException = true
                    pendingException = e
            nextIndex++
        throw pendingException if hasPendingException
        i++
    to