[Fix #10962] Fix a false positive for `Lint/ShadowingOuterLocalVariab…

…le` when conditional with if/elsif/else branches

Fix: #10962

changelog/fix_a_false_positive_for_lint_shadowing_outer_local_variable.md

@@ -0,0 +1 @@
+* [#10962](https://github.com/rubocop/rubocop/pull/10962): Fix a false positive for `Lint/ShadowingOuterLocalVariable` when conditional with if/elsif/else branches. ([@ydah][])

lib/rubocop/cop/lint/shadowing_outer_local_variable.rb

@@ -64,14 +64,26 @@ def before_declaring_variable(variable, variable_table)
         end
 
         def same_conditions_node_different_branch?(variable, outer_local_variable)
-          variable_node = variable.scope.node.parent
+          variable_node = variable_node(variable)
           return false unless variable_node.conditional?
 
           outer_local_variable_node =
             find_conditional_node_from_ascendant(outer_local_variable.declaration_node)
           return true unless outer_local_variable_node
 
-          outer_local_variable_node.conditional? && variable_node == outer_local_variable_node
+          outer_local_variable_node.conditional? &&
+            (variable_node == outer_local_variable_node ||
+              variable_node == outer_local_variable_node.else_branch)
+        end
+
+        def variable_node(variable)
+          parent_node = variable.scope.node.parent
+
+          if parent_node.when_type?
+            parent_node.parent
+          else
+            parent_node
+          end
         end
 
         def find_conditional_node_from_ascendant(node)

spec/rubocop/cop/lint/shadowing_outer_local_variable_spec.rb

@@ -111,6 +111,9 @@ def some_method
                            ^^^ Shadowing outer local variable - `foo`.
               end
             end
+          elsif other_condition?
+            bar.each do |foo|
+            end
           else
             bar.each do |foo|
             end
@@ -152,6 +155,9 @@ def some_method
             bar.each do |foo|
                          ^^^ Shadowing outer local variable - `foo`.
             end
+          when bar then
+            bar.each do |foo|
+            end
           else
             bar.each do |foo|
             end
@@ -168,6 +174,9 @@ def some_method
         def some_method
           if condition?
             foo = 1
+          elsif other_condition?
+            bar.each do |foo|
+            end
           else
             bar.each do |foo|
             end