One-liner to install peerDependencies

Here it is:

node -e "console.log(Object.keys(require('./package.json').peerDependencies).join(' '))" | xargs yarn add

How it works

Let's say we have peerDependencies in our package.json like this:

    ...
  },
  "peerDependencies": {
    "react": "^17.0.2",
    "react-dom": "^17.0.2"
  }
}

We'll see one by one:

1. Load the package.json and get the peerDependencies.
   

   Welcome to Node.js v15.14.0.
   > require('./package.json').peerDependencies
   { react: '^17.0.2', 'react-dom': '^17.0.2' }
   

2. Object.keys function collects the keys of the object and put them together in the array.
   

   Welcome to Node.js v15.14.0.
   > Object.keys({ react: '^17.0.2', 'react-dom': '^17.0.2' })
   [ 'react', 'react-dom' ]
   

3. join method joins the elements with the given string.
   

   > [ 'react', 'react-dom' ].join(' ')
   'react react-dom'
   

4. node -e evaluates the given script.
   

   $ node -e "console.log('react react-dom')"
   'react react-dom'
   

5. Pass it to the yarn add with xargs.
   

   $ node -e "console.log('react react-dom')" | xargs yarn add
   yarn add v1.22.5
   [1/4] Resolving packages...
   [2/4] Fetching packages...
   [########------------------
   

Done 🥳