Warnings about peer dependencies when running npm install

Question

I'm trying to update my React/Firebase project with

npm install --save firebase-functions@latest

and I get a lot of warnings:

npm WARN [email protected] requires a peer of react@~0.14.8 || ^15.0.0 || ^16.0.0 but none is installed. You must install peer dependencies yourself.
npm WARN [email protected] requires a peer of react-dom@~0.14.8 || ^15.0.0 || ^16.0.0 but none is installed. You must install peer dependencies yourself.
npm WARN [email protected] requires a peer of firebase-admin@~5.12.0 but none is installed. You must install peer dependencies yourself.

I'm a newbie so not sure which command should I run to fix the warnings.

Answer 1

Install it by hand:

With npm 5.0.0 or above (edited):

npm install react@^16.0.0
npm install react-dom@^16.0.0
npm install firebase-admin@~5.12.0
npm install firebase-functions@latest

Before npm 5.0.0 (original):

npm install --save react@^16.0.0
npm install --save react-dom@^16.0.0
npm install --save firebase-admin@~5.12.0
npm install --save firebase-functions@latest