Building React App inside of Node server best practice - node.js

Question

Have a react repo and a node repo. The are on the same root directory like so:
--myReactApp
--myNodeServer
I have a script in the React app that builds the React app and places the generated files into the Node server's public directory.
npm run-script build
#Remove the files from the server directory
rm -r ../myNodeServer/public/*
#copy over new files
cp -r ./build/. ../myNodeServer/public
This is all good, but now I am doing CI/CD with Jenkin's pipeline and it pulls the myNodeServer repo that does not have the React app in the public folder. I don't think it is best practice to include generated files in the myNodeServer's public directory, so I don't want to check in the React app into the the Node repo.
What do developer's generally do in the this situation. Is it possible to pull from 2 different repos in a pipeline script.
Right now my script looks like this:
pipeline {
agent any
tools {nodejs "Node8"}
environment {
DBPASSWORD = credentials('DBPASSWORD')
DEPLOYSECRET = credentials('DEPLOYSECRET')
}
stages {
stage('NPM Install') {
steps {
sh 'npm install'
}
}
stage('Unit Test') {
steps {
sh 'env PORT=3090 DBUSER=username DBPASSWORD=$DBPASSWORD DEPLOYSecret=$DEPLOYSECRET ENV=unitTest ./node_modules/mocha/bin/_mocha --timeout 10000 --timeout 0 --ui bdd --recursive ./test'
}
}
}
}