Just joined, and do apologize if I make mistakes in asking my question and showing visual aids.

TLDR:

• I have a full-stack project with a client and server directories, each with their own packages.
• An .env file is located in server directory; dotenv package is in the same directory.
• Running test data via seeds.js succeeds in retrieving an env variable name for MongoDB; running server.js fails to retrieve an env variable name.
• Both js files talk to connection.js to establish a connection to MongoDB via process.env.MONGODB_URI.
• connection.js has require('dotenv').config() loader.

Story:
I’m trying to get .env to be found and read in my server directory, but only my test data seeds.js file is able to capture the env variable it needs to talk to MongoDB, while my server.js can’t grab any.

I would post images to show folder structure, but don’t have that privilege.
Root has client and server directories for front-end and back-end. My problem resides in server.

server
|--config
|  |--connection.js
|
|--models
|--node_modules <part of .gitignore
|--schemas
|--seeders
|  |--cleanDB.js
|  |--seeds.js
|
|--utils
|  |--auth.js
|  |--dateFormat.js
|
| .env <part of .gitignore
| .gitignore
| package-lock.json
| package.json
| server.js
| vercel.json

In my .env is the following:

MONGODB_URI=mongodb+srv://[USERNAME]:[PASSWORD]@adncluster.8xdqpdg.mongodb.net/[DBNAME]?retryWrites=true&w=majority
JWT_TOKEN=[REDACTED]
JWT_EXP=2h
PORT=3001

config directory houses connection.js that initiates a connection to MongoDB. It’s also where require.('dotenv').config() is located since there are two other js files trying to talk to this js file – server.js and seeds.js. seeds.js is located under seeders directory.

connection.js:

require('dotenv').config();
const mongoose = require('mongoose');

mongoose.connect(process.env.MONGODB_URI);
module.exports = mongoose.connection;

Both server.js and seeds.js start with a const db declaration, obviously with a small path adjustment due to their locations:

server.js:

const db = require('./config/connection');

seeds.js:

const db = require("../config/connection");

According to my console log, seeds.js is able to populate the database with test data, whereas server.js is grabbing undefined env variables before an error log is thrown, stating MongooseError ran into an undefined URI parameter. Neither js file has a dotenv config line.

I’ve tried customizing the dotenv line to be require('dotenv').config({ path: "./.env" }) and still the same undefined for server.js.

This is where I am stuck. The token and expiration are being requested from a middleware auth.js located in utils directory, but it is called upon via server.js.

I’m happy to adjust this post if I need to show more code or explain something differently. This has been driving me insane for the whole week, I’ve read articles on this, even read other users’ problems here on stackoverflow, yet mine will not budge from undefined.