Add autocorrection for Rails/ReflectionClassName

CHANGELOG.md

@@ -6,6 +6,10 @@
 
 * [#297](https://github.com/rubocop-hq/rubocop-rails/pull/297): Handle an upstream Ruby issue where the DidYouMean module is not available, which would break the `Rails/UnknownEnv` cop. ([@taylorthurlow][])
 
+### New features
+
+* [#299](https://github.com/rubocop-hq/rubocop-rails/pull/299): Add autocorrection for `Rails/ReflectionClassName`. ([@tejasbubane][])
+
 ## 2.7.0 (2020-07-21)
 
 ### New features

docs/modules/ROOT/pages/cops_rails.adoc

@@ -2903,7 +2903,7 @@ end
 
 | Enabled
 | Yes
-| No
+| Yes
 | 0.64
 | -
 |===

lib/rubocop/cop/rails/reflection_class_name.rb

@@ -13,7 +13,9 @@ module Rails
       #
       #   # good
       #   has_many :accounts, class_name: 'Account'
-      class ReflectionClassName < Cop
+      class ReflectionClassName < Base
+        extend AutoCorrector
+
         MSG = 'Use a string value for `class_name`.'
 
         def_node_matcher :association_with_reflection, <<~PATTERN
@@ -23,14 +25,24 @@ class ReflectionClassName < Cop
         PATTERN
 
         def_node_matcher :reflection_class_name, <<~PATTERN
-          (pair (sym :class_name) [!dstr !str !sym])
+          (pair (sym :class_name) $[!dstr !str !sym])
         PATTERN
 
         def on_send(node)
-          association_with_reflection(node) do |reflection_class_name|
-            add_offense(node, location: reflection_class_name.loc.expression)
+          association_with_reflection(node) do |reflection|
+            add_offense(reflection) do |corrector|
+              class_node = reflection_class_name(reflection)
+              corrector.replace(class_node, replacement(class_node))
+            end
           end
         end
+
+        private
+
+        def replacement(class_node)
+          replacement_node = class_node.send_type? ? class_node.children.first : class_node
+          replacement_node.source.inspect
+        end
       end
     end
   end

spec/rubocop/cop/rails/reflection_class_name_spec.rb

@@ -11,27 +11,43 @@
         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 '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