bar.js

// require, exports, and module are injected automatically
// a and b had to be injected explicitly

var UTIL = require("util");
exports.result = UTIL.add(a, b);

foo.js

// these are not explicitly injected by "load":
typeof require === "undefined";
typeof exports === "undefined";
typeof module === "undefined";

return a + b;

main.js

var ASSERT = require("assert");

// load
ASSERT.equal(load("foo")({a: 10, b: 20}), 30);

// require.once
var BAR = require.once("bar", {a: 10, b: 20});
ASSERT.equal(BAR.result, 30);