Develop Reference

Error: Cannot find module './src/handlers/buttons.js' after migrating all files to a ./src folder [duplicate]

Let's say I have this directory structure
/Project
/node_modules
/SomeModule
bar.js
/config
/file.json
foo.js
-
foo.js:
require('bar');
-
bar.js:
fs.readdir('./config'); // returns ['file.json']
var file = require('../../../config/file.json');
Is it right that the readdir works from the file is being included (foo.js) and require works from the file it's been called (bar.js)?
Or am I missing something?
Thank you

As Dan D. expressed, fs.readdir uses process.cwd() as start point, while require() uses __dirname. If you want, you can always resolve from one path to another, getting an absolute path both would interpret the same way, like so:
var path = require('path');
route = path.resolve(process.cwd(), route);
That way, if using __dirname as start point it will ignore process.cwd(), else it will use it to generate the full path.
For example, assume process.cwd() is /home/usr/node/:
if route is ./directory, it will become /home/usr/node/directory
if route is /home/usr/node/directory, it will be left as is
I hope it works for you :D

"." not being parsed as part of a require() Node.js

I've been working on a project and ran into an issue when I was reorganizing my files. The "." on my requires are not being parsed.
When I run my program I get a
Error: Cannot find module './src/map/createMap.js'
Here is my code:
server.js (main file):
process.chdir(__dirname);
//Completely unrelated code...
const gameConsole = require('./src/backend/console.js');
gameConsole.start();
console.js:
const {createMap} = require('./src/map/createMap.js'); << Error thrown here
const Server = require('./server.js').Server; << Error thrown here if I use path.resolve()
I've tried using path.resolve(), and that works fine. When I log process.cwd() it has the path of my root directory (the one with server.js). I am considering storing the paths as global variables. Thanks for your help.
EDITS:
Sample of file structure:
(root)
|_server.js
|_src
|_backend
| |_console.js
|_map
|_createMap.js
Here is createMap.js, on my git repo: https://github.com/ArkinSolomon/zombie-fight/blob/master/src/map/createMap.js

From the code you've linked, the path to ./src/map/createMap.js in console.js is wrong.
The correct path would be
../map/createMap.js
Go up 1 folder ../ then you've access to map folder
And for server in console.js, the path would be:
const { Server } = require('../../server.js')
Go up 2 folder ../../ as console.js is 2 folders deep relative to server.js

What about to use "../map/createMap.js"?

node dotenv won't work with pm2

I have an application where locally (without pm2) all the environment variables in the .env file work just fine using dotenv.
But on the server where I'm using pm2 to run the app, the environment variables remain undefined.
The pm2 commands I'm using to run the app on server are:
pm2 start myapp/app.js
pm2 startup
pm2 save

dotenv will read .env file located in the current directory.
When you call pm2 start myapp/app.js it won't search for myapp/.env.
.env // It will try to load this, which doesn't exist
myapp/
app.js
So you have two solutions
use path option:
const path = require('path');
require('dotenv').config({ path: path.join(__dirname, '.env') });
Or call your script from inside myapp/
pm2 start app.js

A good pattern here is to remove dotenv from your code and "require" it on the command line. This makes your code nicely transportable between any environment (including cloud-based) - which is one of the main features of environment variables.
Note: you will still need to install dotenv in your project via npm when running it on a server.
a) code up your .env file alongside your script (e.g. app.js)
b) to run your script without pm2:
node -r dotenv/config app.js
c) in pm2.config.js:
module.exports = {
apps : [{
name : 'My Application',
script : 'app.js',
node_args : '-r dotenv/config',
...
}],
}
and then
pm2 start pm2.config.js
note: the use of dotenv/config on the command line is one of the best practices recommended by dotenv themselves
edit 2021: for completeness - as my answer has got some ticks, I wanted to add a 4th option to the list:
d) combined pm2/env config
module.exports = { apps : [{
name : 'My Application',
script : 'app.js',
env : {
PORT: 5010,
DB_STRING: 'mongodb://localhost:27017',
...
},
}]};
This will be useful if you are treating your pm2.config as environmental configuration and outside of git etc. It just negates the need for a separate .env, which may suit you. It negates the need for dotenv completely as pm2 injects the env variables into your script's process

you have kill you pm2 process first
try
pm2 kill
then restart pm2 using
pm2 start app.js

I had the same problem but it wasnt explained clearly so here is the solution based on
github user vmarchaud comment.
This also fixes the issue people had with #Andy Lorenz solution.
In my case i wanted to create an ecosystem file for multiple apps but i was keep getting
Error: Cannot find module 'dotenv/config'
The solution was easy.
You have to declar cwd, aka the project folder where the dotenv/config will be read from.
module.exports = {
apps: [{
name: 'app1 name',
script: 'app1.js',
cwd: '/path/to/folder/',
exec_mode: 'fork_mode',
node_args: '-r dotenv/config',
}, {
name: 'app2 name',
script: 'app2.js',
cwd: '/path/to/folder/',
instances: 'max',
exec_mode: 'cluster',
node_args: '-r dotenv/config',
}],
};

You can parse .env using dotenv lib end set them manually in ecosystem.config.js
ecosystem.config.js:
const { calcPath, getEnvVariables } = require('./helpers');
module.exports = {
apps: [
{
script: calcPath('../dist/app.js'),
name: 'dev',
env: getEnvVariables(),
},
],
};
helpers.js:
const path = require('path');
const dotenv = require('dotenv');
const fs = require('fs');
function calcPath(relativePath) {
return path.join(__dirname, relativePath);
}
// this function will parce `.env` file but not set them to `process.env`
const getEnvVariables = () => {
const envConfig = dotenv.parse(fs.readFileSync(calcPath('.env')));
const requiredEnvVariables = ['MODE'];
for (envVariable of requiredEnvVariables) {
if (!envConfig[envVariable]) {
throw new Error(`Environment variable "${envVariable}" is not set`);
}
}
return envConfig;
};

None of this worked for me because I was using cluster mode.
I installed dotenv as dev dependency at the root (I was using yarn workspaces too).
Then I did this:
require('dotenv').config({ path: 'path/to/your/.env' })
module.exports = {
apps: [
{
name: 'app',
script: 'server/dist/index.js',
instances: 2,
exec_mode: 'cluster',
instance_var: 'APP_INSTANCE_SEQ',
// listen_timeout: 10000,
// restart_delay: 10000,
}
]
}

I use a much simpler version of #Marcos answer:
.env
app.js
for example we need to store token in .env file and pass it right to app.js:
inside .env
token=value
inside app.js:
require('dotenv').config();
console.log(process.env.token)
Also, don't forget. If you add .env file to .gitignore and then git pull you repo on VPS or smth, you need to copy .env file manually, otherwise your app won't work.
And in some cases it's important in what area you are using your config, so make sure that NODE_ENV=production string is added to your .env file.
After all you could use pm2 start app.js right from your app's folder.

This was my project setup..
/src/app.ts
which than compiled into dist folder.
/dist/app.js
my .env file was outside dist folder so it wasn't accessible.
this is the command i tried.
pm2 start app.js --env=.env

Dotenv not loading properly

I am trying to access some environment variables using process.env that were loaded by dotenv.
My folder structure :
.env
src
-- - server.js
My server.js configuration :
(...)
import auth from './middleware/auth'
import dotenv from 'dotenv'
dotenv.load({
path: '../',
silent: process.env.NODE_ENV === 'production'
})
auth()
// Instantiate app
const app = express();
The file where I try to access process.env variable :
(...)
module.exports = function() {
console.log("env", process.env.MONGODB_URI)
var options = {};
options.jwtFromRequest = ExtractJwt.fromAuthHeader()
options.secretOrKey = process.env.JWT_SECRET
Which logs env, undefined, and then crashes with
TypeError: JwtStrategy requires a secret or key
Even if I move .env into src (same directory as server) and remove path in config, it fails.

It appears that when you specify the path, you need to make it full:
require('dotenv').config({path: __dirname + '/../.env'});
.env being your file

Try this; this should work.
import {} from 'dotenv/config'
import somethingElse from 'somethingElse'
...
[the rest of your code]
This works because of how ES6 modules imports modules.
If you want to dig into more.
Please refer this. https://hacks.mozilla.org/2015/08/es6-in-depth-modules/
As a summary :
When you run a module containing an import declaration, the modules it
imports are loaded first, then each module body is executed in a
depth-first traversal of the dependency graph, avoiding cycles by
skipping anything already executed.
Hope this will help someone.

I'm using require('dotenv').config() on my main nodejs .js entry file and it works just fine.
From the docs:
Path
Default: .env
You can specify a custom path if your file containing environment
variables is named or located differently.
require('dotenv').config({path: '/custom/path/to/your/env/vars'})

use may use:
require('dotenv').config({ path: require('find-config')('.env') })
This will recurse parent directories until it finds a .env file to use.
You can also alternatively use this module called ckey inspired from one-liner above.
.env file from main directory.
# dotenv sample content
USER=sample#gmail.com
PASSWORD=iampassword123
API_KEY=1234567890
some js file from sub-directory
const ck = require('ckey');
const userName = ck.USER; // sample#gmail.com
const password = ck.PASSWORD; // iampassword123
const apiKey = ck.API_KEY; // 1234567890

If you're using a mono-repo which uses a single .env file across multiple packages/work-spaces you can use the following to find the root .env file.
Install the find-up package from npm: https://www.npmjs.com/package/find-up
import find from 'find-up';
export const findEnv = () => find.sync(process.env.ENV_FILE || '.env');

you have to set the dotenv configs at the very top level of your app:
import dotenv from 'dotenv'
dotenv.load({
path: '../',
silent: process.env.NODE_ENV === 'production'
})
(...)
import auth from './middleware/auth'
auth()
// Instantiate app
const app = express();
The order of imports in this case matters since you are loading the environment variables.

dotenv file is not loading environment variables

I have .env file at root folder file
NODE_ENV=development
NODE_HOST=localhost
NODE_PORT=4000
NODE_HTTPS=false
DB_HOST=localhost
DB_USERNAME=user
DB_PASSWORD=user
And server.js file in the root/app/config/server.js folder.
The first line of server.js file is
require('dotenv').config();
I also tried following:
require('dotenv').config({path: '../.env'});
require('dotenv').config({path: '../../.env'});
However, my env variable are not loaded when I run the server.js file
from command prompt
node root/app/config/server.js
If I use the visual studio and press F5, it loads!!
I'm not sure what I'm doing wrong, what I'm missing.
Any suggestion is highly appreciate. Thanks.

How about use require('dotenv').config({path:__dirname+'/./../../.env'}) ?
Your problem seems to be the execution path.

This solved my issues in Node v8.14.1:
const path = require('path')
require('dotenv').config({ path: path.resolve(__dirname, '../.env') })
Simply doing require('dotenv').config({path:__dirname+'/./../../.env'}) resulted in a location that resolved as /some/path/to/env/./../../.env

Here is a single-line solution:
require('dotenv').config({ path: require('find-config')('.env') })
This will recurse parent directories until it finds a .env file to use.
You can also alternatively use this module called ckey inspired from one-liner above.
.env file from main directory.
# dotenv sample content
USER=sample#gmail.com
PASSWORD=iampassword123
API_KEY=1234567890
some js file from sub-directory
const ck = require('ckey');
const userName = ck.USER; // sample#gmail.com
const password = ck.PASSWORD; // iampassword123
const apiKey = ck.API_KEY; // 1234567890

If you are invoking dotenv from a nested file, and your .env file is at the project root, the way you want to connect the dots is via the following:
require('dotenv').config({path:'relative/path/to/your/.env'})

One of the comments in #DavidP's answer notes logging the output of dotenv.config with
console.log(require("dotenv").config())
This will output a log of the config and display errors. In my case it indicated the config method was referencing the current directory instead of the
parent directory which contained my .env file. I was able to reference that with the following
require('dotenv').config({path: '../.env'})

I've had this problem and it turned out that REACT only loads variables prefixed with REACT_APP_
VueJs can have a similar issue as it expects variables to be prefixed with: VUE_APP_

In the remote case that you arrive till this point, my issue was quite dumber:
I wrongly named my env variables with colon ":" instead of equals "=". Rookie mistake but the resulting behavior was not loading the misspelled variables assignment.
# dotenv sample content
# correct assignment
USER=sample#gmail.com
# wrong assignment (will not load env var)
USER : sample#gmail.com

This solved the issue for me:
const path = require('path');
require('dotenv').config({
path: path.resolve('config.env'),
});

Be sure to load .env at the beginning of the entry file (e.g. index.js or server.js). Sometimes, the order of execution loads the environment variables after the services are initiated. And, by using __dirname, it can easily point to the file required relative to the current file.
Here my project structure is like this.
.
├─ src
│ └─ index.ts
└─ .env
// index.ts
import dotenv from 'dotenv';
import path from 'path';
dotenv.config({path: path.join(__dirname, '..', '.env')});
...

Try this:
const dotenv = require('dotenv');
dotenv.config({ path: process.cwd() + '/config/config.env' });
worked for me idk how??

You can first debug by using console.log(require('dotenv').config()).
In my scenario, my .env file is in root directory and I need to use it in a nested directory. The result gives me { parsed: { DATABASE_URL: 'mongodb://localhost/vidly', PORT: '8080' } }. So I simply parse the result and store it in a variable const dotenv = require('dotenv').config().parsed;. Then access my DATABASE_URL like a JS object: dotenv.DATABASE_URL

It took me a few head scratches, and the tip to log the output of the require statement to console was really helpful. console.log(require('dotenv').config());
Turns out I was running my app from my user/ directory with nodemon application_name/. and that was making dotenv look for the .env file in my home dir instead of the app's. I was lazy by skipping one cd and that cost me a few minutes.

const path = require('path');
const dotenv = require('dotenv');
dotenv.config({ path: path.resolve(__dirname, '../config.env') })

In my case .env was read fine, but not .env.local.
Updating package.json to name .env into .env.local ( cp ./.env.local .env) solved the problem:
"myscript": "cp ./.env.local .env && node ./scripts/myscript.js"

if config.env file and index.js file both present in the same directory:
then, file: index.js
const path = require('path');
// Set port from environment variables
dotenv.config({path: 'config.env'})
const PORT = process.env.PORT || 8080
file: config.env:
PORT = 4000

One time I have got the same problem. Dotenv did not load .env file. I tried to fix this problem with a path config, to put .env file in a root folder, to put .env in the folder where the file is running and nothing helps me. Then I just trashed Node_modules folder, reinstall all dependencies and it works correctly

You can need the path of the .env file relative to the current working directory from where the application was launched.
You can create this path like this:
const path = require('path')
require('dotenv').config({path: path.relative(process.cwd(), path.join(__dirname,'.env'))});
process.cwd() returns the absolute path of the working directory.
__dirname returns the absolute path of the application.
path.join() adds the path of the .env-file to the path of the application. so if your .env file is nested deeper, just add the folders (e.g. path.join(__dirname, 'config', 'secret','.env'))
path.relative() creates the relative path.

I'am using:
import findUp from 'find-up';
dotenv.config({ path: findUp.sync('.env') });

I found an option debug: true to be sent in the config which showed me the following:
[dotenv][DEBUG] "PORT" is already defined in `process.env` and was NOT overwritten
I added overwrite: true and got it working:
[dotenv][DEBUG] "PORT" is already defined in `process.env` and WAS overwritten
I know I might be too late answering, but decided to share my findings after hours of checking the documentation.

Typescript.
if you are trying to resolve __dirname and you are compiling your source folder in another folder, make sure that you edit __dirname. in my case i am compiling ts in dist folder and env files are not located in dist folder, but in the root folder. so you should delete /dist from __dirname. To debug it, you can call error() function which returns error if there is problem with reading env file.
require('dotenv').config({
path: __dirname.replace('\dist','') + `${process.env.NODE_ENV}.env`
}); # To debug .error()
another thing, when you set env variables make sure that following:
no space between variable and (&&) as following
"scripts": {
"build": "npx tsc",
"start": "set NODE_ENV=production&& node dist/index.js",
},

The fastest fix here, just into seconds, add the variables to the platform you are using in my case render.com

What worked for me using Playwright / typescript:
1 create file and place at the root of the project: global-setup.ts
add inside:
async function globalSetup() {
// Configure ENV variables
require('dotenv').config()
}
export default globalSetup
2 Then use this file into playwright.config.ts
as: globalSetup: require.resolve('./global-setup'),
In this way, global conf is created, and pickup in every single test.

Use only absolute path if you are using some other tool(installed globally) to call your config file somewhere ...
require('dotenv').config({
path: '/path/to/my/project/.env',
});

One silly mistake I did was i used colon ":" in place of "="
I used below
USER:root
But it should be
USER=root

If nothing helps put your .env outside the src folder if you have folder structure like
-src/
- index.js
- env.js (where you call dotenv.config)
// you may call dotenv.config anywhere but entry point is best.
.env (file outside the src folder)

My failer was the path keyword . should be the P not capital Letter . that was so funny