shim.js #1

"use strict";

var keys  = require("../keys")
  , value = require("../valid-value")
  , max   = Math.max;

module.exports = function (dest, src /*, …srcn*/) {
	var error, i, length = max(arguments.length, 2), assign;
	dest = Object(value(dest));
	assign = function (key) {
		try {
			dest[key] = src[key];
		} catch (e) {
			if (!error) error = e;
		}
	};
	for (i = 1; i < length; ++i) {
		src = arguments[i];
		keys(src).forEach(assign);
	}
	if (error !== undefined) throw error;
	return dest;
};