How to get nodemon to kill process when a program crashes? - node.js

Question

Perhaps I'm missing something, since I've never encountered this before, but I'm trying to run a Node/Express/Babel setup with nodemon, and every time there is a crash (almost), nodemon leaves the port in use, so I have to manually kill the process. I'm using Node 11.15.0 and MacOS 10.13.6 and the error I get is
events.js:170
throw er; // Unhandled 'error' event
^
Error: listen EADDRINUSE: address already in use :::4321
at Server.setupListenHandle [as _listen2] (net.js:1259:14)
at listenInCluster (net.js:1307:12)
at Server.listen (net.js:1395:7)
at listen (/Users/robertanthony/Documents/Projects/sandbox/axa/src/index.js:27:10)
at $initialConnection.$initialConnection.then (/Users/thisuser/Documents/Projects/sandbox/axa/node_modules/mongoose/lib/connection.js:723:13)
at processTicksAndRejections (internal/process/task_queues.js:86:5)
Emitted 'error' event at:
at emitErrorNT (net.js:1286:8)
at processTicksAndRejections (internal/process/task_queues.js:81:17)
[nodemon] app crashed - waiting for file changes before starting...
My package.json is
{
"scripts": {
"start": "nodemon --exec babel-node src/index.js",
"lint": "eslint \"src/**/*.{js}\" --quiet",
"test": "echo \"Error: no test specified\" && exit 1"
},
"dependencies": {
"body-parser": "^1.19.0",
"cors": "^2.8.5",
"dotenv": "^8.1.0",
"express": "^4.17.1",
"express-async-handler": "^1.1.4",
"express-jwt": "^5.3.1",
"express-jwt-permissions": "^1.3.1",
"express-session": "^1.16.2",
"jsonwebtoken": "^8.5.1",
"mongodb": "^3.3.2",
"mongoose": "^5.7.1",
"winston": "^3.2.1"
},
"devDependencies": {
"#babel/core": "^7.6.0",
"#babel/node": "^7.6.1",
"#babel/preset-env": "^7.5.5",
"eslint": "^6.2.2",
"eslint-config-prettier": "^6.1.0",
"nodemon": "^1.19.2",
"prettier": "^1.18.2"
}
}
Perhaps it's something I'm doing wrong? Any help much appreciated -- If it's not obvious what the solution is, is there any way to run babel without nodemon? I tried 'node --exec' but that didn't work…