Why does npm install remove all installed modules?

Question

npm

I add a new dependency to the project, I write to the console
npm install quill-image-extend-module --save-dev(for example)
The new module is loaded, the old ones are removed from the node_modules folder.
everything remains in place in package.json

After that, I do npm installit and it downloads all the modules again.
This is fine?

Answer 1

It's an npm bug It 's been fixed
in the latest version, you can upgrade
npm i -g [email protected]

Answer 2

ok check json syntax of package.json file
it will check first package.json and check node_modules packages then remove old ones and download new ones deleting previous ones.