Support auto-correction for Rails/ScopeArgs

This PR supports auto-correction for `Rails/ScopeArgs`.

CHANGELOG.md

@@ -5,6 +5,7 @@
 ### New features
 
 * [#521](https://github.com/rubocop/rubocop-rails/pull/521): Support auto-correction for `Rails/Output`. ([@koic][])
+* [#520](https://github.com/rubocop/rubocop-rails/pull/520): Support auto-correction for `Rails/ScopeArgs`. ([@koic][])
 
 ## 2.11.3 (2021-07-11)
 

config/default.yml

@@ -714,6 +714,7 @@ Rails/ScopeArgs:
   Description: 'Checks the arguments of ActiveRecord scopes.'
   Enabled: true
   VersionAdded: '0.19'
+  VersionChanged: '2.12'
   Include:
     - app/models/**/*.rb
 

docs/modules/ROOT/pages/cops_rails.adoc

@@ -4300,9 +4300,9 @@ Service::Mailer::update
 
 | Enabled
 | Yes
-| No
+| Yes
 | 0.19
-| -
+| 2.12
 |===
 
 This cop checks for scope calls where it was passed

lib/rubocop/cop/rails/scope_args.rb

@@ -14,14 +14,18 @@ module Rails
       #   # good
       #   scope :something, -> { where(something: true) }
       class ScopeArgs < Base
+        extend AutoCorrector
+
         MSG = 'Use `lambda`/`proc` instead of a plain method call.'
         RESTRICT_ON_SEND = %i[scope].freeze
 
         def_node_matcher :scope?, '(send nil? :scope _ $send)'
 
         def on_send(node)
           scope?(node) do |second_arg|
-            add_offense(second_arg)
+            add_offense(second_arg) do |corrector|
+              corrector.replace(second_arg, "-> { #{second_arg.source} }")
+            end
           end
         end
       end

spec/rubocop/cop/rails/scope_args_spec.rb

@@ -1,11 +1,15 @@
 # frozen_string_literal: true
 
 RSpec.describe RuboCop::Cop::Rails::ScopeArgs, :config do
-  it 'registers an offense a scope with a method arg' do
+  it 'registers and corrects an offense a scope with a method arg' do
     expect_offense(<<~RUBY)
       scope :active, where(active: true)
                      ^^^^^^^^^^^^^^^^^^^ Use `lambda`/`proc` instead of a plain method call.
     RUBY
+
+    expect_correction(<<~RUBY)
+      scope :active, -> { where(active: true) }
+    RUBY
   end
 
   it 'accepts a non send argument' do