Why is process.env.NODE_ENV undefined?

Setting and managing NODE_ENV

The operating environment of your Node.js applications is heavily influenced by environment variables. Here's how to optimally position them:

Establish NODE_ENV before starting your Node.js application

You need to prepare your environment as follows before starting your app:

• For Windows:

  SET NODE_ENV=development
  

• For macOS/Linux:

  export NODE_ENV=development
  

Run Node.js with NODE_ENV being specified on the fly

Start your Node.js application with NODE_ENV specified inline:

NODE_ENV=production node server.js


Trim NODE_ENV to eliminate unexpected characters

Ensure NODE_ENV is devoid of unexpected whitespace that could lead to bugs:

var nodeEnv = (process.env.NODE_ENV || '').trim(); 


Utilize cross-env for cross-platform setting of NODE_ENV

Use the cross-env package within your package.json scripts to set environment variables in a cross-platform fashion:

"scripts": {
  "start": "cross-env NODE_ENV=production node server.js"
}


You can install the package via npm:

npm install --save-dev cross-env


Assign a default value to NODE_ENV

Establish a default value for NODE_ENV in your code:

var env = process.env.NODE_ENV || 'development'; // NODE_ENV is homeless? Give it a "development" home


This way, a default environment gets assigned in the absence of an explicit NODE_ENV.

Expanded tactics and potential issues

Dynamically loading NODE_ENV

Tailoring NODE_ENV based on the deployment context is critical for apps operating in various environments. Consider procedures for automatically setting NODE_ENV in the needed contexts.

Consistency across the codebase

Ensure NODE_ENV is referenced consistently through your codebase. Failure to do so may lead to inconsistent results which are difficult to debug.

Platform specific-command formats

Certain shell environments do not support inline NODE_ENV setting. Windows command prompt, for instance, differs from PowerShell and Unix shells. Always verify your setting across the platforms you target.

Ignored environment files

Version control systems like git often ignore .env files to avoid exposing sensitive data. When cloning a repository or deploying, remember to account for needed .env files or set environment variables appropriately.