watch command doesn't work

[TaherehSharifian]

"server": "npm run watch --prefix server",
"client": "npm start --prefix client",
"watch": "npm run server & npm run client",

I added these three lines of code into my root package.json and when running npm run watch in the terminal, only the server comes up and the client won't start. And I have this warning in the chrome:
VM86:5 crbug/1173575, non-JS module files deprecated.

my node version is 18.17.1

Has anyone else faced this problem?

[TaherehSharifian]

I was able to make this command work as the way it sould with an extra package named concurrently as a development dependency and change the command to be :
"watch": "concurrently \"npm run server\" \"npm run client\"",
But I'd rather make it work without any auxiliary package.

any ideas how?

[aviralrabbit1]

I was able to make this command work as the way it sould with an extra package named concurrently as a development dependency and change the command to be : "watch": "concurrently \"npm run server\" \"npm run client\"", But I'd rather make it work without any auxiliary package.

any ideas how?

Have you tried &&

"watch": "npm run server && npm run client",

Reply if it works.