.env with debugging breakpoint using vscode and dotenv npm - node.js

Question

I'm using a nodejs server side api, setting up environment variables with dotenv npm package, and running the code from npm scripts in package.json as below:
"scripts": {
"local": "cross-env NODE_ENV=local nodemon ./bin/www"
}
What I need is to configure my .vscode/launch.json file.
Currently it looks like:
{
// Use IntelliSense to learn about possible attributes.
// Hover to view descriptions of existing attributes.
// For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
"version": "0.2.0",
"configurations": []
}
Kindly guide me. Thanks,
Gopal.R
dotenv npm package
Visual Studio Code - Launch configurations

Answer 1

You would want to set the .dotenv environmental variable up like:
NODE_ENV=local
Then to require it in your debugger, you would want to add it into your launch.json configurations like:
"runtimeArgs": [
"--require=dotenv/config"
]
Here it is in context:
{
// Use IntelliSense to learn about possible attributes.
// Hover to view descriptions of existing attributes.
// For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
"version": "0.2.0",
"configurations": [
{
"type": "node",
"request": "launch",
"name": "Launch | local with dotenv config",
"program": "${workspaceFolder}/bin/www/your_script.js",
"runtimeArgs": [
"--require=dotenv/config"
]
}
]
}
--require=dotenv/config is the equivalent of running require('dotenv').config() in your script or node -r dotenv/config your_script.js if you're using the command line.
Here are some alternate examples of where environmental variables can be placed in the config.
{
// Use IntelliSense to learn about possible attributes.
// Hover to view descriptions of existing attributes.
// For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
"version": "0.2.0",
"configurations": [
{
"type": "node",
"request": "launch",
"name": "Launch | local using env file",
"program": "${workspaceFolder}/bin/www/your_script.js",
"envFile": "${workspaceFolder}/.env"
},
{
"type": "node",
"request": "launch",
"name": "Launch | local without dotenv",
"program": "${workspaceFolder}/bin/www/your_script.js",
"env" : {
"NODE_ENV" : "local"
}
}
]
}
Note: This code hasn't been tested... so feedback is welcome.

Answer 2

I had the same question for typescript debugging and I found answer here. Need to specify runtimeArgs and envFile parameters to make it work.
Example of launch.json for TypeScript debugging:
{
"version": "0.2.0",
"configurations": [
{
"type": "pwa-node",
"request": "launch",
"name": "Launch Program",
"skipFiles": [
"<node_internals>/**"
],
"program": "${workspaceFolder}/src/server.ts",
"preLaunchTask": "tsc: build - tsconfig.json",
"outFiles": [
"${workspaceFolder}/built/**/*.js"
],
"runtimeArgs": [
"--require=dotenv/config"
],
"envFile": "${workspaceFolder}/.env"
}
]
}