Rubocop/Hound recommend freezing string literal class names

Question

My project uses HoundCI as a code linter, which I believe internally uses rubocop.

Recently I started noticing this sort of warning -

It appears on every class definition (e.g. class User < ActiveRecord::Base).

I understand the concept of freezing string literals, but why would it expect me to freeze class definitions? Also more importantly, how do I disable it? It's quite annoying to have 10+ of these "errors" polluting our pull requests.

Thank you!

Edit: Looks like it also started appearing on require statements that use string literals, like with rspec tests. This is definitely new and wasn't being flagged previously

Answer 1

It looks like Hound/Rubocop is detecting a violation of the FrozenStringLiteralComment cop.

This cop is designed to help upgrade to Ruby 3.0. It will add the comment # frozen_string_literal: true to the top of files to enable frozen string literals. Frozen string literals will be default in Ruby 3.0. The comment will be added below a shebang and encoding comment. The frozen string literal comment is only valid in Ruby 2.3+.

You can either add the magic comment manually to the top of your files

# frozen_string_literal: true

Or have Rubocop do it for you

$ bundle exec rubocop --auto-correct --only FrozenStringLiteralComment

You can also ignore the cop in your rubocop.yml, Style/FrozenStringLiteralComment