node packge.json scripts - add command to existing script

Question

I'd like to add a command to the "start" script so when I do npm start, first thing that will run is npm install.

My package.json looks as follows:

.
.
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "DEBUG=my-app node src/index.js",
    "dev": "nodemon src/index.js"
  },
.
.
.

I thought about adding npm install inside the start script:

   "start": "npm install DEBUG=my-app node src/index.js",

But this doesn't work so I'd like to get a suggestion, wether if it's even possible..

it's the same syntax as standard shell scripts, so `npm install && DEBUG=my-app node src/index.js` or if you have lots of scripts that you want to run in serial/parallel combinations, it's generally easier to add in [npm-run-all](https://www.npmjs.com/package/npm-run-all) and using its `run-s` and `run-p` ays of running multiple tasks — Mike 'Pomax' Kamermans, Dec 16 '21 at 16:21
That would mean every time you start your app all your modules would installed all over again. Are you really sure that's what you want? — Andy, Dec 16 '21 at 16:24
@Andy yes, my app should be deployed once with a single command. — jrz, Dec 16 '21 at 16:32
@jrz the problem with this would be, that the startup of your app will be quite slow. Additionally if npm has a downtime, you potentially won't be able to start your service. — theshark, Dec 16 '21 at 16:46

JimmyWj4EHiM · Answer 1 · 2021-12-16T16:39:36.937

1

I think you only use the && conector. like:

  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "npm install && DEBUG=my-app node src/index.js",
    "dev": "nodemon src/index.js"
  }

edited Dec 16 '21 at 16:39

answered Dec 16 '21 at 16:23

JimmyWj4EHiM

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score 0 · Answer 2 · answered Dec 16 '21 at 17:01

Andy yes, my app should be deployed once with a single command.

This is a quite a heavy/slow start, installing all modules before starting the app.

That means if I change the code somewhwere in my node server, stop the process and run it again, a full install is gonna happen. I realize that you have a dev script with nodemon, but still.

Another case: If your app crashes on the live server and you need to start it up again then a full install will happen. What happens if a module has gone up a patch or a minor version. That means you will start up a project with different dependencies.

If you're doing this in the ci/cd then a pipeline is usually split up:

Install - npm ci
Build/compile - for example if you have typescript (not in your case)
Run all tests
Remove the devDependencies with npm prune
Start up the process

What you would maybe do is have a script called "pipeline" or something, and then call that.

"pipeline": npm ci && npm run build && npm test && npm prune && npm start

This script would then be called in your pipeline code.

I am actually running it on server-less platform. Maybe you can take a look on that separated thread? https://stackoverflow.com/questions/70410653/running-node-js-on-cloudflare-pages — jrz, Dec 19 '21 at 11:03

node packge.json scripts - add command to existing script

2 Answers2