错误：找不到模块＆＃39;一次＆＃39;

Question

var sample = "this is an [hello] amazing [world]"

var regex = NSRegularExpression(pattern: "\\[.+?\\]"
, options: NSRegularExpressionOptions.CaseInsensitive 
, error: nil)

var matches = regex?.matchesInString(sample, options: nil
, range: NSMakeRange(0, countElements(sample))) as Array<NSTextCheckingResult>

for match in matches {
   let r = (sample as NSString).substringWithRange(match.range)//cast to NSString is required to match range format.
    println("found= \(r)")
}

当我尝试使用nodemon运行Error: Cannot find module 'once' at Function.Module._resolveFilename (module.js:337:15) at Function.Module._load (module.js:287:25) at Module.require (module.js:366:17) at require (module.js:385:17) at Object.<anonymous> (/usr/local/lib/node_modules/nodemon/node_modules/update-notifier/node_modules/latest-version/node_modules/package-json/node_modules/got/node_modules/duplexify/node_modules/end-of-stream/index.js:1:74) at Module._compile (module.js:435:26) at Object.Module._extensions..js (module.js:442:10) at Module.load (module.js:356:32) at Function.Module._load (module.js:311:12) at Module.require (module.js:366:17) at require (module.js:385:17) 时，我收到此错误。我查看了server.js文件夹，并且有一次＆＃39;一次＆＃39;那里的文件夹。我试过了

node_modules

删除整个rm -rf node_modules npm install 文件夹并重新安装，但它不起作用。我也做了

node_modules

仍然没有奏效。

这是package.json

npm install --save once