RSpec style guide VS Ruby style guide

betterspecs.org is a good resource.

Both sites advocate for factories over fixtures (though there is a not clear consensus). With fixtures, test objects are all defined in fixture files with predefined data. Fixtures can be used across tests but modifying an existing fixture can break tests that depend on that fixture. As a codebase grows managing fixtures for all the various states of your object can be difficult. In comparison, factories let you build and configure new objects per test.

Better Specs (RSpec Guidelines with Ruby)

By default, RuboCop will enforce the style defined in the Ruby Community Style Guide. We can tailor it to our specific tastes and context, but let's rely on this basic set of rules to learn how to use RuboCop.

RuboCop is a Ruby static code analyzer (a.k.a. linter) and code formatter. Out of the box it will enforce many of the guidelines outlined in the community Ruby Style Guide. Apart from reporting the problems discovered in your code, RuboCop can also automatically fix many of them for you.

Read more about Ruby.

8. Use a consistent style: Consistency is key when it comes to writing readable code. Use a consistent style throughout your codebase, and follow common Ruby style guides like Ruby Style Guide.

The real standard is to use default rubocop configuration which is based on https://rubystyle.guide/.

It used to, before recently. It literally said, "The and and or keywords are banned."

rubocop/ruby-style-guide

As you see - there are no reference to any technology or framework. There are a lot of best-practices for almost any framework, so you can choose an appropriate one. For example - if you're a rails developer, then you can check https://github.com/rubocop/ruby-style-guide and https://github.com/rubocop/rails-style-guide but if you're a golang developer - https://github.com/uber-go/guide/blob/master/style.md and https://developers.mattermost.com/contribute/more-info/server/style-guide/