Rails has these generators that we can use to customize every new app that we create based on our requirements.

Suppose, we want to create a new Rails app with Postgresql DB instead of the default sqlite3, then we can use the --database alias.

  rails new myapp --database=postgresql
  rails new myapp -d=postgresql

Similarly, we could also use these generator options to remove something we don’t want. For example, if we want to write our tests using RSpec and do not want the unnecessary test directory from getting created. We could use the -T or --skip-test aliases.

  rails new myapp -T
  rails new myapp --skip-test

In Rails 6, the option webpacker got replaced with --javascript to allow apps to with import-map, es-build, or webpacker.

  rails new myapp -j esbuild
  rails new myapp --javascript esbuild

Rails will now allow --js as a new alias along with -j and --javascript to customize apps with javascript.

So, if we need to create apps with esbuild, webpacker, or rollup as our javascript choice, we should be able to use the new alias.

  rails new myapp --js esbuild
  rails new myapp --js webpack
  rails new myapp --js rollup

We should also be able to use --skip-js alias instead of --skip-javascript to skip any javascript option altogether.

  rails new myapp --skip-js esbuild
  rails new myapp --skip-js webpack
  rails new myapp --skip-js rollup

It is a minor enhancement, but it makes a lot more sense as we tend to associate JavaScript with js alias more than j intuitively.

Note: The enhancement is yet to be released in the official Rails version