[Fix #1230] Fix a false positive for Rails/SaveBang if persisted? is checked on parenthesised expression.

Author: Earlopain

changelog/fix_false_positive_for_rails_save_bang.md

@@ -0,0 +1 @@
+* [#1230](https://github.com/rubocop/rubocop-rails/issues/1230): Fix a false positive for `Rails/SaveBang` if `persisted?` is checked on parenthesised expression. ([@earlopain][])

lib/rubocop/cop/rails/save_bang.rb

@@ -196,6 +196,8 @@ def persisted_referenced?(assignment)
         end
 
         def call_to_persisted?(node)
+          node = node.parent.condition if node.parenthesized_call? && node.parent.if_type?
+
           node.send_type? && node.method?(:persisted?)
         end
 

spec/rubocop/cop/rails/save_bang_spec.rb

@@ -638,6 +638,38 @@ def whatever
       RUBY
     end
 
+    it "when using persisted? on the result of #{method} in if assignment" do
+      expect_no_offenses(<<~RUBY)
+        if (user = User.#{method}).persisted?
+          foo(user)
+        else
+          bar(user)
+        end
+      RUBY
+    end
+
+    it "when not using persisted? on the result of #{method} in if assignment" do
+      expect_offense(<<~RUBY, method: method)
+        if (user = User.#{method})
+                        ^{method} Use `#{method}!` instead of `#{method}` if the return value is not checked. Or check `persisted?` on model returned from `#{method}`.
+          foo(user)
+        else
+          bar(user)
+        end
+      RUBY
+    end
+
+    it "when using persisted? on the result of #{method} in elsif assignment" do
+      expect_no_offenses(<<~RUBY)
+        if something
+        elsif (user = User.#{method}).persisted?
+          foo(user)
+        else
+          bar(user)
+        end
+      RUBY
+    end
+
     it "when using #{method} with `||`" do
       expect_no_offenses(<<~RUBY)
         def find_or_create(**opts)