Javascript – Why process.env.username readys the computer hostname (in Windows 10), instead of the key-value pair defined in config.env file

Problem:

I defined username and password in config.env file and tried to retrieve with dotenv package.

When I try to retrieve username, it gets the hostname. Regardless if I define all lowercase letters or uppercase letters; it returns the computer hostname.

Is it with the process.env.username having some variable name collision, and by design it would read the hostname for process.env.username?

Here is snippet code from app.js:

const express = require('express')
const app = express();

const dotenv = require('dotenv')

// Setting up the post for server
dotenv.config({
    path: './utils/config.env',
    override: true
})

console.log(`*** Username: ${process.env.USERNAME}`)
console.log(`*** Username: ${process.env.USER_NAME}`)
console.log(`*** Username: ${process.env.UNAME}`)
console.log(`*** Password: ${process.env.password}`)

const PORT = process.env.PORT;
app.listen(PORT, () => {
    console.log(`Server has started on port: ${process.env.PORT} in ${process.env.NODE_ENV} mode.`)
})

Here is what is inside config.env file:

PORT = 3000
NODE_ENV = development

USERNAME = USERNAME1
USER_NAME = USERNAME2
UNAME = USERNAME3
password = password@123

How should I understand this and (I guess) what is the recommended way of defining username and password in config.env file when we deal with NodeJS?

When I added ‘_’ (like USER_NAME, or any other form of ‘username’); then it works as expected.

Solution:

Dotenv by default will not overwrite existing shell variables.

You can configure dotenv with the override option to work around this.

require('dotenv').config({
  path: './utils/config.env',
  override: true,
});

This will ignore any existing environment variables with the same names as those in your config.env file.