Move a module from devDependencies to dependencies in npm package.json

Question

If you want to do the opposite (i.e. move a module from dependencies to devDependencies) just do:

npm install <module_name> --save-dev

or shorthand:

npm i <module_name> -D

shorthand to move from devDependencies to dependencies (prod):

npm i <module_name> -P

Yes! to move a module from devDependencies to dependencies:

npm install <module_name> --save-prod

In yarn:

Move a module from devDependencies to dependencies:

yarn remove <module_name> --dev && yarn add <module_name> 

Move a module from dependencies to devDependencies :

yarn remove <module_name> && yarn add <module_name> --dev

As said in the comments, the command actually deletes the module and reinstall it in the new place.

The problem with using npm or yarn commands is that there is a chance that the version that is re-added is a different version than the one that is currently used. If this is what you want - both a move and an upgrade - then go ahead and use the accepted answer.

If not, simply manually edit your package.json to move the line from the devDependencies object to the dependencies object (creating it if necessary). You can go the other direction too.

The lock file doesn't hold any information about if things are prod or dev dependencies, so that doesn't need to be updated. You can do a npm/yarn install afterwards to fix up any flags in the lock files.

The issue of using npm install is that you end up with updated versions. What worked for me is:

1. Moving them to the intended part (dev, or prod)
2. Removing them from node_modules folder
3. Execute npm install

That kept all versions intact.

If your project doesn't have a lockfile or a shrinkwrap file yet, you can simply move the corresponding line in your package.json.

(I'm not recommending not using lockfiles)