[Fix #10734] Handle ClobberingError in `Style/NestedTernaryOperator…

…` when there are multiple nested ternaries.

changelog/fix_handle_clobberingerror_in.md

@@ -0,0 +1 @@
+* [#10734](https://github.com/rubocop/rubocop/issues/10734): Handle `ClobberingError` in `Style/NestedTernaryOperator` when there are multiple nested ternaries. ([@dvandersluis][])

lib/rubocop/cop/style/nested_ternary_operator.rb

@@ -17,6 +17,8 @@ module Style
       #   end
       class NestedTernaryOperator < Base
         extend AutoCorrector
+        include RangeHelp
+        include IgnoredNode
 
         MSG = 'Ternary operators must not be nested. Prefer `if` or `else` constructs instead.'
 
@@ -26,14 +28,10 @@ def on_if(node)
           node.each_descendant(:if).select(&:ternary?).each do |nested_ternary|
             add_offense(nested_ternary) do |corrector|
               if_node = if_node(nested_ternary)
+              next if part_of_ignored_node?(if_node)
 
-              corrector.replace(if_node, <<~RUBY.chop)
-                if #{if_node.condition.source}
-                  #{remove_parentheses(if_node.if_branch.source)}
-                else
-                  #{if_node.else_branch.source}
-                end
-              RUBY
+              autocorrect(corrector, if_node)
+              ignore_node(if_node)
             end
           end
         end
@@ -47,11 +45,25 @@ def if_node(node)
           if_node(node)
         end
 
+        def autocorrect(corrector, if_node)
+          replace_loc_and_whitespace(corrector, if_node.loc.question, "\n")
+          replace_loc_and_whitespace(corrector, if_node.loc.colon, "\nelse\n")
+          corrector.replace(if_node.if_branch, remove_parentheses(if_node.if_branch.source))
+          corrector.wrap(if_node, 'if ', "\nend")
+        end
+
         def remove_parentheses(source)
           return source unless source.start_with?('(')
 
           source.delete_prefix('(').delete_suffix(')')
         end
+
+        def replace_loc_and_whitespace(corrector, range, replacement)
+          corrector.replace(
+            range_with_surrounding_space(range: range, whitespace: true),
+            replacement
+          )
+        end
       end
     end
   end

spec/rubocop/cop/style/nested_ternary_operator_spec.rb

@@ -9,9 +9,9 @@
 
     expect_correction(<<~RUBY)
       if a
-        b ? b1 : b2
+      b ? b1 : b2
       else
-        a2
+      a2
       end
     RUBY
   end
@@ -25,9 +25,9 @@
 
     expect_correction(<<~RUBY)
       if cond
-        foo
+      foo
       else
-        bar(foo.a ? foo.b : foo) { |e, k| e.nil? ? nil : e[k] }
+      bar(foo.a ? foo.b : foo) { |e, k| e.nil? ? nil : e[k] }
       end
     RUBY
   end
@@ -40,9 +40,9 @@
 
     expect_correction(<<~RUBY)
       if x
-        y + (z ? 1 : 0)
+      y + (z ? 1 : 0)
       else
-        nil
+      nil
       end
     RUBY
   end
@@ -56,4 +56,24 @@
       end
     RUBY
   end
+
+  it 'can handle multiple nested ternaries' do
+    expect_offense(<<~RUBY)
+      a ? b : c ? d : e ? f : g
+                      ^^^^^^^^^ Ternary operators must not be nested. Prefer `if` or `else` constructs instead.
+              ^^^^^^^^^^^^^^^^^ Ternary operators must not be nested. Prefer `if` or `else` constructs instead.
+    RUBY
+
+    expect_correction(<<~RUBY)
+      if a
+      b
+      else
+      if c
+      d
+      else
+      e ? f : g
+      end
+      end
+    RUBY
+  end
 end