To use $NODE_ENV with if condition in windows cmd

Question

"scripts": {
  "start": "if [[ $NODE_ENV == 'production' ]]; then node ./bin/www; else nodemon ./bin/www; fi"
},

The above code is used in Unix terminal and I want to use the same in windows cmd.

But when I try to do that I get NODE_ENV was unexpected at this time.

I want a proper code which can be executed in windows cmd.

Answer 1

Consider the following cross-platform solution that works successfully regardless of whether the shell is cmd (windows) or sh (*nix). It essentially utilizes node.js to replicate the same conditional logic and to shell out the appropriate command.

"scripts": {
  "start": "node -e \"const cmd = process.env.NODE_ENV === 'production' ? 'node' : 'nodemon'; require('child_process').execSync(cmd + ' ./bin/www', { stdio: [0,1,2] });\""
}

---

Explanation:

The start npm script does the following:

1. Utilizes the node.js command line option -e to evaluate the inline JavaScript.

2. Using the conditional (ternary) operator, i.e. the part that reads:

   const cmd = process.env.NODE_ENV === 'production' ? 'node' : 'nodemon'
   

   • We utilize the process.env property to check the value of the NODE_ENV environment variable.

   • If the value of the NODE_ENV environment variable equals production we assign the node command to the cmd variable. Otherwise we assign the nodemon command.

3. In the part that reads:

   require('child_process').execSync(cmd + ' ./bin/www', { stdio: [0,1,2] });
   

   • We require the builtin execSync() method from the child_process module.
   • Then we execute either the node ./bin/www or the nodemon ./bin/www command based on what was obtained at point 2 (above).
   • The stdio part configures the pipes for stdin, stdout, stderr in the child process.