Ruby style guide
This is a GitLab-specific style guide for Ruby code. Everything documented in this page can be reopened for discussion.
We use RuboCop to enforce Ruby style guide rules.
Where a RuboCop rule is absent, refer to the following style guides as general guidelines to write idiomatic Ruby:
Generally, if a style is not covered by existing RuboCop rules or the above style guides, it shouldn't be a blocker.
Some styles we have decided no one should not have a strong opinion on.
Styles we have no rule for
These styles are not backed by a RuboCop rule.
For every style added to this section, link the discussion from the section's version history note to provide context and serve as a reference.
Instance variable access using
Introduced in GitLab 14.1.
Instance variables can be accessed in a variety of ways in a class:
# public class Foo attr_reader :my_var def initialize(my_var) @my_var = my_var end def do_stuff puts my_var end end # private class Foo def initialize(my_var) @my_var = my_var end private attr_reader :my_var def do_stuff puts my_var end end # direct class Foo def initialize(my_var) @my_var = my_var end private def do_stuff puts @my_var end end
Public attributes should only be used if they are accessed outside of the class. There is not a strong opinion on what strategy is used when attributes are only accessed internally, as long as there is consistency in related code.
Newlines style guide
In addition to the RuboCops
Cop/LineBreakAroundConditionalBlock that enforce some newline styles, we have the following guidelines that are not backed by RuboCop.
Rule: separate code with newlines only to group together related logic
# bad def method issue = Issue.new issue.save render json: issue end
# good def method issue = Issue.new issue.save render json: issue end
Rule: newline before block
# bad def method issue = Issue.new if issue.save render json: issue end end
# good def method issue = Issue.new if issue.save render json: issue end end
Exception: no need for a newline when code block starts or ends right inside another code block
# bad def method if issue if issue.valid? issue.save end end end
# good def method if issue if issue.valid? issue.save end end end
Styles we have no opinion on
If a RuboCop rule is proposed and we choose not to add it, we should document that decision in this guide so it is more discoverable and link the relevant discussion as a reference.
Quoting string literals
Due to the sheer amount of work to rectify, we do not care whether string literals are single or double-quoted.
Previous discussions include: