.env with debugging breakpoint using vscode and dotenv npm

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.

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"
        }
    ]
}