d8cjs.js

function Module(dir) {
  this.dir = dir;
  this.exports = {};
}

function loadModule(dirname, filename) {
  var i = Realm.create();
  Realm.eval(i, '__dirname = '+ JSON.stringify(dirname));
  Realm.eval(i, '__filename = '+ JSON.stringify(filename));
  Realm.eval(i, 'module = new Realm.shared.Module(__dirname)');
  Realm.eval(i, 'exports = module.exports');
  Realm.eval(i, 'require = module.require.bind(module)');
  try {
    Realm.eval(i, read(filename));
    return Realm.eval(i, 'module');
  } catch(e) {
    print('failed to load '+filename);
    throw e;
  }
}

const cached = Object.create(null);
const splitPathRe = /^(\/?|)([\s\S]*?)((?:\.{1,2}|[^\/]+?|)(\.[^.\/]*|))(?:[\/]*)$/;

Module.prototype.require = function require(request) {
  var file = resolve(this.dir, request);
  var parts = splitPathRe.exec(file);
  var dirname  = parts[1] + parts[2];
  var basename = parts[3];
  var ext      = parts[4];
  var filename = dirname + basename;
  if (!ext) {
    filename += '.js';
  }
  var module = cached[filename];
  if (module) {
    return module.exports;
  }
  module = loadModule(dirname, filename);
  cached[filename] = module;
  return module.exports;
};

Realm.shared = {
  Module: Module
};

if (typeof arguments === 'undefined' || arguments.length === 0) {
  print('d8 d8cjs.js -- path/to/require');
} else {
  var m = new Module(cwd());
  m.require(arguments[0]);
}

function cwd() {
  return os.system('pwd').trim();
}

function resolve(dir, path) {
  var parts = dir.split('/').concat(path.split('/'));
  parts = normalize(parts);
  return '/' + parts.join('/');
}

function normalize(parts) {
  var res = [];
  for (var i = 0; i < parts.length; i++) {
    var p = parts[i];
    if (!p || p === '.') {
      continue;
    }
    if (p === '..') {
      if (res.length && res[res.length - 1] !== '..') {
        res.pop();
      }
    } else {
      res.push(p);
    }
  }
  return res;
}