Finds the names of all modules required in the file.

required.js

var JSONSelect = require("JSONSelect");
var Reflect = require("reflect");

var ast = Reflect.parse(read(__filename));

var required = JSONSelect.match('.callee:has(:root > .name:val("require")) ~ .arguments :first-child .value', ast);
// ["JSONSelect", "reflect", "fs", "path"]

function read (path) {
    return require("fs").readFileSync(require("path").resolve(path), "utf8");
}