[Fix rubocop#12237] Fix Style/NestedTernaryOperator autocorrection

Fix autocorrection to correctly support conditionals between nested ternaries.

changelog/fix_style_nested_ternary_operator_should_allow.md

@@ -0,0 +1 @@
+* [#12237](https://github.com/rubocop/rubocop/issues/12237): Fix `Style/NestedTernaryOperator` autocorrection to support conditionals between nested ternaries. ([@stevegeek][])

lib/rubocop/cop/style/nested_ternary_operator.rb

@@ -40,7 +40,7 @@ def on_if(node)
 
         def if_node(node)
           node = node.parent
-          return node if node.if_type?
+          return node if node.if_type? && node.ternary?
 
           if_node(node)
         end

spec/rubocop/cop/style/nested_ternary_operator_spec.rb

@@ -76,4 +76,23 @@
       end
     RUBY
   end
+
+  it 'can handle nested ternaries mixed with conditionals' do
+    expect_offense(<<~RUBY)
+      a ? (if b
+        c ? 1 : 2
+        ^^^^^^^^^ Ternary operators must not be nested. Prefer `if` or `else` constructs instead.
+      end) : 3
+    RUBY
+
+    expect_correction(<<~RUBY)
+      if a
+      if b
+        c ? 1 : 2
+      end
+      else
+      3
+      end
+    RUBY
+  end
 end