Allow ignoring scopes for inverse_of cop

With rails/rails#43358, Rails can now infer
inverse_of for associations with a scope when
`config.active_record.automatic_scope_inversing = true`.

This commit adds an `IgnoreScopes` option to the inverse_of cop allowing
us to disable the cop for scopes when the new Rails option is set to
`true`.

I considered having the default for `IgnoreScopes` change based on the
Rails version since this is the default for new Rails >= 7.0
applications, but existing applications that upgrade to 7.0 wouldn't
necessarily have the option set and in that case changing the
rubocop-rails default behavior would be a breaking change.

CHANGELOG.md

@@ -519,3 +519,4 @@
 [@leoarnold]: https://github.com/leoarnold
 [@TonyArra]: https://github.com/TonyArra
 [@tachyons]: https://github.com/tachyons
+[@composerinteralia]: https://github.com/composerinteralia

changelog/new_allow_ignoring_scopes_for_inverse_of_cop.md

@@ -0,0 +1 @@
+* [#614](https://github.com/rubocop/rubocop-rails/pull/614): Add `IgnoreScopes` config option for `Rails/InverseOf` cop. ([@composerinteralia][])

lib/rubocop/cop/rails/inverse_of.rb

@@ -25,7 +25,7 @@ module Rails
       #     belongs_to :blog
       #   end
       #
-      # @example
+      # @example IgnoreScopes: false (default)
       #   # bad
       #   class Blog < ApplicationRecord
       #     has_many :posts, -> { order(published_at: :desc) }
@@ -65,6 +65,16 @@ module Rails
       #              inverse_of: false)
       #   end
       #
+      # @example IgnoreScopes: true
+      #   # good
+      #   class Blog < ApplicationRecord
+      #     has_many :posts, -> { order(published_at: :desc) }
+      #   end
+      #
+      #   class Post < ApplicationRecord
+      #     belongs_to :blog
+      #   end
+      #
       # @example
       #   # bad
       #   class Picture < ApplicationRecord
@@ -189,7 +199,7 @@ def on_send(node)
         end
 
         def scope?(arguments)
-          arguments.any?(&:block_type?)
+          !ignore_scopes? && arguments.any?(&:block_type?)
         end
 
         def options_requiring_inverse_of?(options)
@@ -236,6 +246,10 @@ def message(options)
             SPECIFY_MSG
           end
         end
+
+        def ignore_scopes?
+          cop_config['IgnoreScopes'] == true
+        end
       end
     end
   end

spec/rubocop/cop/rails/inverse_of_spec.rb

@@ -25,6 +25,18 @@ class Person
         end
       RUBY
     end
+
+    context 'when `IgnoreScopes: true`' do
+      let(:cop_config) do
+        { 'IgnoreScopes' => true }
+      end
+
+      it 'does not register an offense when not specifying `:inverse_of`' do
+        expect_no_offenses(
+          'has_many :foo, -> () { where(bar: true) }'
+        )
+      end
+    end
   end
 
   context 'with option preventing automatic inverse' do