How to start node app with development flag?

Question

At top of my app.js file I put

NODE_ENV=\'development\';

but I get error that NODE_ENV is not defined. But in the nodejs documentation is says

Answer 1

By using NPM you might to be used the follow scripts in the package.json:

  "scripts": {
    "start": "nodemon ./bin/www",
    "dev_win": "set NODE_ENV=development && node ./bin/www >> /romba/log/api.log 2>> /romba/log/error.log",
    "prod_win": "set NODE_ENV=production && node ./bin/www >> /romba/log/api.log 2>> /romba/log/error.log"
    "prod_nix": "NODE_ENV=production node ./bin/www >> /romba/log/api.log 2>> /romba/log/_error.log"
  },...

To start one of the script use the command:

 npm run-script prod_win

In the JavaScript code I check the condition:

process.env.NODE_ENV.indexOf('production') > -1