Don't do it...

1. yarn <package>

   Do not install dependencies as yarn <package dependency>. We use lerna and the way it works for the project is by installing dependencies to the packages or servers that requires it. In most cases, you can just add the package to frontend or backend by running following

   to add to the frontend server so browser gets it

   lerna add --scope=*fronted-server <package>

> to add to the backend server for nodejs to use it

lerna add --scope=*backend-server <package>

If a dependency is just needed by one package, you can add to that package's package.json file

lerna add --scope=<package name> <package>

Ideally, root package.json should have all the devDependencies of the project while packages & servers file references should be under dependencies section as shown here.

Sometimes we may need to pin a package as other dependencies can bring some older versions of the package we want to add. In that case we can pin the required package version by adding to the pacakge.json. But make sure you don't have different version of the package in servers or packages otherwise a duplciate package will be added to its nodemodules.

Do

1. Each package version should be uniform across the repository

   Before adding a <package dependency>, see if the package of different version exist. If it exist then update that version to the required version.

2. You can edit one of the packages or servers's package.json file directly to add a dependencies and then run yarn lerna to install them. This is a easy way to install a known version by adding to the target pacakage.json file.