Uncaught ReferenceError: layer is not defined'

events.js:183

      throw er; // Unhandled 'error' event

      ^



Error: listen EADDRINUSE :::3000

    at Server.setupListenHandle [as _listen2] (net.js:1360:14)

    at listenInCluster (net.js:1401:12)

    at Server.listen (net.js:1485:7)

    at Function.listen (E:\VsCode\mock-github-api\node_modules\express\lib\appli                                                                                                                                  cation.js:618:24)

    at Object.<anonymous> (E:\VsCode\mock-github-api\index.js:180:5)

    at Module._compile (module.js:653:30)

    at Object.Module._extensions..js (module.js:664:10)

    at Module.load (module.js:566:32)

    at tryModuleLoad (module.js:506:12)

    at Function.Module._load (module.js:498:3)

npm ERR! code ELIFECYCLE

npm ERR! errno 1

npm ERR! mock-github-api@1.0.0 start: `node index`

npm ERR! Exit status 1

npm ERR!

npm ERR! Failed at the mock-github-api@1.0.0 start script.

npm ERR! This is probably not a problem with npm. There is likely additional log                                                                                                                                  ging output above.



npm ERR! A complete log of this run can be found in:

npm ERR!     D:\Program Files\nodejs\node_cache\_logs\2019-03-19T06_44_19_978Z-d                                                                                                                                  ebug.log

app.all('*', function(req, res, next) {
    res.header("Access-Control-Allow-Origin", "*");
    res.header("Access-Control-Allow-Headers", "X-Requested-With");
    res.header("Access-Control-Allow-Methods","PUT,POST,GET,DELETE,OPTIONS");
    res.header("X-Powered-By",' 3.2.1')
    res.header("Content-Type", "application/json;charset=utf-8");
    next();
});