rails heroku - how to install javascript dependences that needs 'npm install ...'

Question

I am deploying my rails app to heroku. I want to use some javascript libraries which want us to install npm dependencies like this:

npm install abc

So, locally I can do like installing npm and doing 'npm install abc'. Not sure how to do it in heroku along with my rails app.

Answer 1

Use the multiple builds approach from Heroku:

Using Multiple Buildpacks for an App

By having the NodeJS one first and then the Ruby one, Heroku will install your node dependencies before anything happens in Ruby.

heroku buildpacks:set heroku/ruby
heroku buildpacks:add --index 1 heroku/nodejs

That will set the build pack to heroku/ruby and then add the heroku/nodejs one but in index 1 (which is first). To confirm this, run:

heroku buildpacks
=== ... Buildpack
1. heroku/nodejs
2. heroku/ruby