Add autocorrection for Rails/ReflectionClassName cop

changelog/change_add_autocorrect_to_reflection_class_name.md

@@ -0,0 +1 @@
+* [#299](https://github.com/rubocop/rubocop-rails/pull/299): Add autocorrection for `Rails/ReflectionClassName`. ([@tejasbubane][])

lib/rubocop/cop/rails/reflection_class_name.rb

@@ -18,6 +18,8 @@ module Rails
       #   # good
       #   has_many :accounts, class_name: 'Account'
       class ReflectionClassName < Base
+        extend AutoCorrector
+
         MSG = 'Use a string value for `class_name`.'
         RESTRICT_ON_SEND = %i[has_many has_one belongs_to].freeze
         ALLOWED_REFLECTION_CLASS_TYPES = %i[dstr str sym].freeze
@@ -32,12 +34,18 @@ class ReflectionClassName < Base
           (pair (sym :class_name) #reflection_class_value?)
         PATTERN
 
+        def_node_matcher :const_or_string, <<~PATTERN
+          {$(const nil? _) (send $(const nil? _) :name) (send $(const nil? _) :to_s)}
+        PATTERN
+
         def on_send(node)
           association_with_reflection(node) do |reflection_class_name|
             return if reflection_class_name.value.send_type? && reflection_class_name.value.receiver.nil?
             return if reflection_class_name.value.lvar_type? && str_assigned?(reflection_class_name)
 
-            add_offense(reflection_class_name.loc.expression)
+            add_offense(reflection_class_name.loc.expression) do |corrector|
+              autocorrect(corrector, reflection_class_name)
+            end
           end
         end
 
@@ -64,6 +72,14 @@ def reflection_class_value?(class_value)
             !ALLOWED_REFLECTION_CLASS_TYPES.include?(class_value.type)
           end
         end
+
+        def autocorrect(corrector, class_config)
+          class_value = class_config.value
+          replacement = const_or_string(class_value)
+          return unless replacement.present?
+
+          corrector.replace(class_value, replacement.source.inspect)
+        end
       end
     end
   end

spec/rubocop/cop/rails/reflection_class_name_spec.rb

@@ -7,34 +7,54 @@
         has_many :accounts, class_name: Account, foreign_key: :account_id
                             ^^^^^^^^^^^^^^^^^^^ Use a string value for `class_name`.
       RUBY
+
+      expect_correction(<<~RUBY)
+        has_many :accounts, class_name: "Account", foreign_key: :account_id
+      RUBY
     end
 
     it '.name' do
       expect_offense(<<~RUBY)
         has_many :accounts, class_name: Account.name
                             ^^^^^^^^^^^^^^^^^^^^^^^^ Use a string value for `class_name`.
       RUBY
+
+      expect_correction(<<~RUBY)
+        has_many :accounts, class_name: "Account"
+      RUBY
     end
 
     it '.to_s' do
       expect_offense(<<~RUBY)
         has_many :accounts, class_name: Account.to_s
                             ^^^^^^^^^^^^^^^^^^^^^^^^ Use a string value for `class_name`.
       RUBY
+
+      expect_correction(<<~RUBY)
+        has_many :accounts, class_name: "Account"
+      RUBY
     end
 
     it 'has_one' do
       expect_offense(<<~RUBY)
         has_one :account, class_name: Account
                           ^^^^^^^^^^^^^^^^^^^ Use a string value for `class_name`.
       RUBY
+
+      expect_correction(<<~RUBY)
+        has_one :account, class_name: "Account"
+      RUBY
     end
 
     it 'belongs_to' do
       expect_offense(<<~RUBY)
         belongs_to :account, class_name: Account
                              ^^^^^^^^^^^^^^^^^^^ Use a string value for `class_name`.
       RUBY
+
+      expect_correction(<<~RUBY)
+        belongs_to :account, class_name: "Account"
+      RUBY
     end
   end