why so much js?.md

Why do I need 106mb of JS for an empty rails app?

$ cd /tmp
$ rails -v 
Rails 6.0.3.2
$ rails new my-app 
Using -T -d postgresql from /Users/rileytg/.railsrc # use postgres, dont use tests (usually add rspec). this is a fairly common rails stack.
...
Bundle complete! 14 Gemfile dependencies, 65 gems now installed.
...
Installing all JavaScript dependencies [4.2.2]
         run  yarn add @rails/[email protected] from "."
...
✨  Done in 17.36s.
Installing dev server for live reloading
         run  yarn add --dev webpack-dev-server from "."
...
✨  Done in 8.24s.
Webpacker successfully installed 🎉 🍰
$ cd my-app/
$ du -h -d 1
 60K	./app
 32K	./bin                               🧐
120K	./config                          🧐 
106M	./node_modules                  🧐🧐🧐🧐🧐🧐🧐🧐🧐🧐🧐🧐🧐
  0B	./storage                         🧐
 16K	./public                            🧐
  0B	./lib
4.0K	./db
  0B	./log
 72K	./.git
 27M	./tmp
  0B	./vendor
134M	.

Whats in node_modules/?

$ du -h -d 1 node_modules/ | gsort -hr |  wc -l
     768

# top 10
$ du -h -d 1 node_modules/ | gsort -hr |  head -n 10
106M	node_modules/
7.4M	node_modules//@babel
6.8M	node_modules//core-js
5.9M	node_modules//node-sass
4.8M	node_modules//lodash
3.2M	node_modules//caniuse-lite
3.1M	node_modules//es-abstract
2.8M	node_modules//csso
2.6M	node_modules//webpack
1.9M	node_modules//node-gyp

# middle(ish) 10
Rileys-MBP:my-app rileytg$ du -h -d 1 node_modules/ | gsort -hr |  head -n 384 | tail -n 10
 32K	node_modules//randombytes
 32K	node_modules//prr
 32K	node_modules//postcss-safe-parser
 32K	node_modules//postcss-media-minmax
 32K	node_modules//postcss-flexbugs-fixes
 32K	node_modules//postcss-color-gray
 32K	node_modules//parse-asn1
 32K	node_modules//object-copy
 32K	node_modules//npmlog
 32K	node_modules//mississippi
 
 # 20-30
$ du -h -d 1 node_modules/ | gsort -hr |  head -n 30 | tail -n 10
964K	node_modules//@types
848K	node_modules//webpack-dev-server
844K	node_modules//async
840K	node_modules//snapdragon
836K	node_modules//pako
824K	node_modules//source-map
752K	node_modules//neo-async
708K	node_modules//bluebird
676K	node_modules//uri-js
652K	node_modules//postcss-calc