Don't register offenses for Rails/WhereExists when exists? is given multiple or splat arguments

Author: lovro-bikic

changelog/fix_rails_where_exists_behavior_for_exists_with_multiple_arguments.md

@@ -0,0 +1 @@
+* [#1511](https://github.com/rubocop/rubocop-rails/pull/1511): Don't register offenses for `Rails/WhereExists` when `exists?` is given multiple or splat arguments. ([@lovro-bikic][])

lib/rubocop/cop/rails/where_exists.rb

@@ -58,8 +58,8 @@ class WhereExists < Base
           (call (call _ :where $...) :exists?)
         PATTERN
 
-        def_node_matcher :exists_with_args?, <<~PATTERN
-          (call _ :exists? $...)
+        def_node_matcher :exists_with_arg?, <<~PATTERN
+          (call _ :exists? $!splat_type?)
         PATTERN
 
         def on_send(node)
@@ -91,7 +91,7 @@ def find_offenses?(node, &block)
           if exists_style?
             where_exists_call?(node, &block)
           elsif where_style?
-            exists_with_args?(node, &block)
+            exists_with_arg?(node) { |arg| yield([arg]) }
           end
         end
 

spec/rubocop/cop/rails/where_exists_spec.rb

@@ -142,25 +142,26 @@
       RUBY
     end
 
-    it 'registers an offense and corrects when using `exists?` with an multiple arguments' do
-      expect_offense(<<~RUBY)
+    it 'does not register an offense when using `exists?` with multiple arguments' do
+      expect_no_offenses(<<~RUBY)
         User.exists?('name = ?', 'john')
-             ^^^^^^^^^^^^^^^^^^^^^^^^^^^ Prefer `where('name = ?', 'john').exists?` over `exists?('name = ?', 'john')`.
       RUBY
+    end
 
-      expect_correction(<<~RUBY)
-        User.where('name = ?', 'john').exists?
+    it 'does not register an offense when using `exists?` with splat argument' do
+      expect_no_offenses(<<~RUBY)
+        User.exists?(*conditions)
       RUBY
     end
 
     it 'registers an offense when using implicit receiver and arg' do
       expect_offense(<<~RUBY)
-        exists?('name = ?', 'john')
-        ^^^^^^^^^^^^^^^^^^^^^^^^^^^ Prefer `where('name = ?', 'john').exists?` over `exists?('name = ?', 'john')`.
+        exists?(['name = ?', 'john'])
+        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Prefer `where(['name = ?', 'john']).exists?` over `exists?(['name = ?', 'john'])`.
       RUBY
 
       expect_correction(<<~RUBY)
-        where('name = ?', 'john').exists?
+        where(['name = ?', 'john']).exists?
       RUBY
     end