gistfile1.js

  // needs to handle the following cases
  //
  // require("a.<ext>")
  //   -> a.<ext>
  //
  // require("a")
  //   -> a
  //   -> a.<ext>
  //   -> a/index.<ext>
  function findModulePath (request, paths) {
    var fs = requireNative('fs')
      , exts = Object.keys(extensions);

    paths = request.charAt(0) === "/" ? [""] : paths;

    // check if the file exists and is not a directory
    var tryFile = function (requestPath) {
      try {
        stats = fs.statSync(requestPath);
        if (stats && !stats.isDirectory()) {
          return requestPath;
        }
      } catch(e) {}
      return false;
    };

    // given a path check a the file exists with any of the set extensions
    var tryExtensions = function (p, extension) {
      for (var i = 0, EL = exts.length; i < EL; i++) {
        f = tryFile(p + exts[i]);
        if (f) { return f; }
      }
      return false;
    };

    // For each path
    for (var i = 0, PL = paths.length; i < PL; i++) {
      var p = paths[i]
              // try to join the request to the path
        , f = tryFile(path.join(p, request)) ||
              // try it with each of the extensions
              tryExtensions(path.join(p, request)) ||
              // try it with each of the extensions at "index"
              tryExtensions(path.join(p, request, "index"));
      if (f) { return f; }
    }
    return false;
  }