Merge pull request #9587 from dvandersluis/issue/9586

[Fix #9586] Update `Naming/RescuedExceptionsVariableName` to not register on inner rescues when nested.

changelog/fix_update_naming_rescued_exceptions_variable_name.md

@@ -0,0 +1 @@
+* [#9586](https://github.com/rubocop/rubocop/issues/9586): Update `Naming/RescuedExceptionsVariableName` to not register on inner rescues when nested. ([@dvandersluis][])

lib/rubocop/cop/naming/rescued_exceptions_variable_name.rb

@@ -9,6 +9,11 @@ module Naming
       # The `PreferredName` config option takes a `String`. It represents
       # the required name of the variable. Its default is `e`.
       #
+      # NOTE: This cop does not consider nested rescues because it cannot
+      # guarantee that the variable from the outer rescue is not used within
+      # the inner rescue (in which case, changing the inner variable would
+      # shadow the outer variable).
+      #
       # @example PreferredName: e (default)
       #   # bad
       #   begin
@@ -62,6 +67,11 @@ def on_resbody(node)
           offending_name = variable_name(node)
           return unless offending_name
 
+          # Handle nested rescues by only requiring the outer one to use the
+          # configured variable name, so that nested rescues don't use the same
+          # variable.
+          return if node.each_ancestor(:resbody).any?
+
           preferred_name = preferred_name(offending_name)
           return if preferred_name.to_sym == offending_name
 

spec/rubocop/cop/naming/rescued_exceptions_variable_name_spec.rb

@@ -391,6 +391,59 @@ def main
         RUBY
       end
     end
+
+    context 'with multiple branches' do
+      it 'registers and corrects each offense' do
+        expect_offense(<<~RUBY)
+          begin
+            something
+          rescue MyException => exc
+                                ^^^ Use `e` instead of `exc`.
+            # do something
+          rescue OtherException => exc
+                                   ^^^ Use `e` instead of `exc`.
+            # do something else
+          end
+        RUBY
+
+        expect_correction(<<~RUBY)
+          begin
+            something
+          rescue MyException => e
+            # do something
+          rescue OtherException => e
+            # do something else
+          end
+        RUBY
+      end
+    end
+
+    context 'with nested rescues' do
+      it 'handles it' do
+        expect_offense(<<~RUBY)
+          begin
+          rescue StandardError => e1
+                                  ^^ Use `e` instead of `e1`.
+            begin
+              log(e1)
+            rescue StandardError => e2
+              log(e1, e2)
+            end
+          end
+        RUBY
+
+        expect_correction(<<~RUBY)
+          begin
+          rescue StandardError => e
+            begin
+              log(e)
+            rescue StandardError => e2
+              log(e, e2)
+            end
+          end
+        RUBY
+      end
+    end
   end
 
   context 'with the `PreferredName` setup' do