electron/lib/common/reset-search-paths.js

const path = require('path');
const Module = require('module');

// Clear Node's global search paths.
Module.globalPaths.length = 0;

// Clear current and parent(init.coffee)'s search paths.
module.paths = [];

module.parent.paths = [];

// Prevent Node from adding paths outside this app to search paths.
Module._nodeModulePaths = function(from) {
  var dir, i, part, parts, paths, skipOutsidePaths, splitRe, tip;
  from = path.resolve(from);

  // If "from" is outside the app then we do nothing.
  skipOutsidePaths = from.startsWith(process.resourcesPath);

  // Following logoic is copied from module.js.
  splitRe = process.platform === 'win32' ? /[\/\\]/ : /\//;
  paths = [];
  parts = from.split(splitRe);
  for (tip = i = parts.length - 1; i >= 0; tip = i += -1) {
    part = parts[tip];
    if (part === 'node_modules') {
      continue;
    }
    dir = parts.slice(0, tip + 1).join(path.sep);
    if (skipOutsidePaths && !dir.startsWith(process.resourcesPath)) {
      break;
    }
    paths.push(path.join(dir, 'node_modules'));
  }
  return paths;
};