astro add causes dev dependencies to be removed from node_modules

[TheOtterlord]

What version of astro are you using?

2.10.5

Are you using an SSR adapter? If so, which one?

None

What package manager are you using?

npm

What operating system are you using?

Linux

What browser are you using?

Firefox

Describe the Bug

Using astro add causes a weird issue, where any existing installed dev dependencies will be removed from node_modules.

Stackblitz has repro instructions, but here's some you can also use locally.

1. new project (npm create astro@latest)
2. install a dev dependency (e.g. npm i daisyui -D)
3. check it exists in node_modules
4. use astro add (e.g. npx astro add react -y)
5. check to find the dev dependency missing from node_modules, but still in the package.json

What's the expected result?

Dev dependencies to still be present, after using astro add.

Link to Minimal Reproducible Example

https://stackblitz.com/edit/github-3sk8rq?file=md!README.md&on=stackblitz

Participation

• I am willing to submit a pull request for this issue.

[natemoo-re]

Thank you for the lovely reproduction, as usual! This is a weird one. I wonder if we're accidentally running npm install in production mode? That's probably the case.

[jacobdalamb]

Thank you for the lovely reproduction, as usual! This is a weird one. I wonder if we're accidentally running npm install in production mode? That's probably the case.

I want to create a PR for this issue and based on what you said, I can't seem to find where this might be happening in the index.ts file of astro add or in install-package.ts file