code: function resolveNodeModules(pkgpath) {
    let dir = pkgpath;
    let dirs = [];
    let depth = maxFileSystemDepth;
    let parent;
    let nodeModulespath;
  
    while (true) {
      parent = path.dirname(dir);
      // Stop if we hit max file system depth or root
      // Convert to lowercase to fix problems on Windows
      if (!--depth || parent.toLowerCase() === dir.toLowerCase()) {
        break;
      }
  
      nodeModulespath = path.resolve(dir, 'node_modules');
  
      if (exists(nodeModulespath)) dirs.push(nodeModulespath);
  
      // Walk
      dir = parent;
    }
  
    return dirs;
  }
docs: Gather all node_modules directories reachable from 'pkgpath'
  @param {String} pkgpath
  @returns {Array}