Mongoose: Error cannot find module debug

Question

I'm building a basic MEAN webapp and am new to the stack. I have the front end running, but as soon as I add the following lines to app.js:

var mongoose = require('mongoose');
require('./models/test');
mongoose.connect('mongodb://localhost:3000/design-data-test');

I get the following error in terminal:

Error: Cannot find module 'debug'
    at Function.Module._resolveFilename (module.js:336:15)
    at Function.Module._load (module.js:278:25)
    at Module.require (module.js:365:17)
    at require (module.js:384:17)
    at Object.<anonymous> (/Users/username/node_modules/mongoose/node_modules/mquery/lib/mquery.js:11:13)
    at Module._compile (module.js:460:26)
    at Object.Module._extensions..js (module.js:478:10)
    at Module.load (module.js:355:32)
    at Function.Module._load (module.js:310:12)
    at Module.require (module.js:365:17)
    at require (module.js:384:17)

And all of my front end code stops running. Mongodb is running on the default port.

How would I go about resolving this error?

Answer 1

For future visitors : You are probably missing a dependency. Make sure you run this first:

npm install

... before you run your app with npm start or node <app>

Answer 2

我认为，如果您通过另一个软件包（例如express或mongoose ）对debug有子依赖关系，但是没有为已部署的应用程序提供依赖项的package.json文件，这会使node.js无法找到debug则可能会发生这种情况。