Enable cops in the Lint Department

Gemfile

@@ -7,3 +7,4 @@ gemspec
 gem "diffy"
 gem "minitest"
 gem "rake"
+gem "rubocop-minitest"

Gemfile.lock

@@ -1,7 +1,8 @@
 PATH
   remote: .
   specs:
-    rubocop-shopify (2.15.1)
+    rubocop-shopify (3.0.0)
+      lint_roller
       rubocop (~> 1.72, >= 1.72.1)
       rubocop-thread_safety (>= 0.7.1)
 
@@ -37,6 +38,10 @@ GEM
     rubocop-ast (1.43.0)
       parser (>= 3.3.7.2)
       prism (~> 1.4)
+    rubocop-minitest (0.37.1)
+      lint_roller (~> 1.1)
+      rubocop (>= 1.72.1, < 2.0)
+      rubocop-ast (>= 1.38.0, < 2.0)
     rubocop-thread_safety (0.7.2)
       lint_roller (~> 1.1)
       rubocop (~> 1.72, >= 1.72.1)
@@ -52,6 +57,7 @@ DEPENDENCIES
   diffy
   minitest
   rake
+  rubocop-minitest
   rubocop-shopify!
 
 BUNDLED WITH

config/default.yml

@@ -0,0 +1,4 @@
+Lint/NoReturnInMemoization:
+  Enabled: true
+  VersionAdded: "3.0.0"
+  Description: "Checks for the use of a `return` with a value in `begin..end` blocks in the context of instance variable assignment such as memoization."

lib/rubocop-shopify.rb

@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+require "rubocop/shopify/version"
+require "rubocop/shopify/plugin"
+
+require "rubocop/cop/lint/no_return_in_memoization"

lib/rubocop/cop/lint/no_return_in_memoization.rb

@@ -0,0 +1,98 @@
+# frozen_string_literal: true
+
+require "rubocop"
+
+module RuboCop
+  module Cop
+    module Lint
+      # Checks for the use of a `return` with a value in `begin..end` blocks
+      # in the context of instance variable assignment such as memoization.
+      # Using `return` with a value in these blocks can lead to unexpected behavior
+      # as the `return` will exit the method that contains and not set the values
+      # of the instance variable.
+      #
+      # @example
+      #
+      #   # bad
+      #   def foo
+      #     @foo ||= begin
+      #       return 1 if bar
+      #       2
+      #     end
+      #   end
+      #
+      #   # bad
+      #   def foo
+      #     @foo = begin
+      #       return 1 if bar
+      #       2
+      #     end
+      #   end
+      #
+      #   # bad
+      #   def foo
+      #     @foo += begin
+      #       return 1 if bar
+      #       2
+      #     end
+      #   end
+      #
+      #   # bad - using return in rescue blocks still exits the method
+      #   def foo
+      #     @foo ||= begin
+      #       bar
+      #     rescue
+      #       return 2 if baz
+      #     end
+      #   end
+      #
+      #   # good
+      #   def foo
+      #     @foo ||= begin
+      #       if bar
+      #         1
+      #       else
+      #         2
+      #       end
+      #     end
+      #   end
+      #
+      #   # good - not an assignment to an instance variable
+      #   def foo
+      #     foo = begin
+      #       return 1 if bar
+      #       2
+      #     end
+      #   end
+      #
+      #   # good - proper exception handling without return
+      #   def foo
+      #     @foo ||= begin
+      #       bar
+      #     rescue
+      #       baz ? 2 : 3
+      #     end
+      #   end
+      class NoReturnInMemoization < ::RuboCop::Cop::Base
+        MSG = 'Do not `return` in `begin..end` blocks in instance variable assignment contexts.'
+
+        def on_or_asgn(node)
+          node.each_node(:kwbegin) do |kwbegin_node|
+            kwbegin_node.each_node(:return) do |return_node|
+              add_offense(return_node)
+            end
+          end
+        end
+
+        def on_op_asgn(node)
+          return unless node.assignment_node.ivasgn_type?
+
+          on_or_asgn(node)
+        end
+
+        alias on_ivasgn on_or_asgn
+        alias on_and_asgn on_or_asgn
+      end
+    end
+  end
+end

lib/rubocop/shopify/plugin.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+require "lint_roller"
+
+module RuboCop
+  module Shopify
+    class Plugin < LintRoller::Plugin
+      def about
+        LintRoller::About.new(
+          name: "rubocop-shopify",
+          version: RuboCop::Shopify::VERSION,
+          homepage: "https://github.com/Shopify/rubocop-shopify",
+          description: "A plugin for RuboCop to enforce Shopify-specific coding standards."
+        )
+      end
+
+      def supported?(context)
+        context.engine == :rubocop
+      end
+
+      def rules(context)
+        LintRoller::Rules.new(
+          type: :path,
+          config_format: :rubocop,
+          value: File.expand_path("../../../config/default.yml", __dir__)
+        )
+      end
+    end
+  end
+end

lib/rubocop/shopify/version.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Shopify
+    VERSION = "3.0.0"
+  end
+end

rubocop-shopify.gemspec

@@ -1,9 +1,14 @@
 # frozen_string_literal: true
 
+lib = File.expand_path("../lib", __FILE__)
+$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
+
+require "rubocop/shopify/version"
+
 Gem::Specification.new do |s|
   s.platform    = Gem::Platform::RUBY
   s.name        = "rubocop-shopify"
-  s.version     = "2.15.1"
+  s.version     = RuboCop::Shopify::VERSION
   s.summary     = "Shopify's style guide for Ruby."
   s.description = "Gem containing the rubocop.yml config that corresponds to " \
     "the implementation of the Shopify's style guide for Ruby."
@@ -14,15 +19,17 @@ Gem::Specification.new do |s|
   s.email    = "[email protected]"
   s.homepage = "https://shopify.github.io/ruby-style-guide/"
 
-  s.files = Dir["rubocop*.yml", "lib/**/*", "LICENSE.md", "README.md"]
+  s.files = Dir["rubocop*.yml", "lib/**/*", "LICENSE.md", "config/default.yml", "README.md"]
 
   s.metadata = {
     "source_code_uri" => "https://github.com/Shopify/ruby-style-guide/tree/v#{s.version}",
     "allowed_push_host" => "https://rubygems.org",
+    "default_lint_roller_plugin" => "RuboCop::Shopify::Plugin"
   }
 
   s.required_ruby_version = ">= 3.2.0"
 
   s.add_dependency("rubocop", "~> 1.72", ">= 1.72.1")
   s.add_dependency("rubocop-thread_safety", ">= 0.7.1")
+  s.add_dependency("lint_roller")
 end