[Request] Remove database connection dependency for model annotations

[tony-pizza]

Context: I want to run model annotations in CI (e.g. GitHub Actions). This currently requires spinning up a MySQL container service, creating our databases and loading the schemas for every annotation job run. This adds extra runner minutes and complexity.

I was honestly surprised to learn a connection was required as I'd assumed annotations were built purely from schema files.

The connection happens in ModelWrapper (see below). I'm sure there's a good reason why database introspection is used here vs inferring from schema files, but I'd like to voice that a connection-less option would be valuable.

annotaterb/lib/annotate_rb/model_annotator/model_wrapper.rb

Lines 37 to 43 in b9554dd

	def connection
	if @klass.respond_to?(:lease_connection)
	@klass.lease_connection
	else
	@klass.connection
	end
	end

Thanks!

[drwl]

This is known and expected behavior -- that AnnotateRb requires the database to annotate. And I get that it would be great if this hard dependency could be removed in CI.

It's been a few years since I last dug into this, but from what I can recall that Rails does not actually care about schema.rb, instead it reads from the database, and AnnotateRb inflects on Rails APIs.

https://guides.rubyonrails.org/active_record_migrations.html#what-are-schema-files-for-questionmark

That being said, this might be possible to do spike with today's LLMs. If you want to give it a try please feel free.