Class: RuboCop::Cop::Lint::ShadowingOuterLocalVariable

Inherits:
Base
  • Object
show all
Defined in:
lib/rubocop/cop/lint/shadowing_outer_local_variable.rb

Overview

This cop checks for the use of local variable names from an outer scope in block arguments or block-local variables. This mirrors the warning given by `ruby -cw` prior to Ruby 2.6: “shadowing outer local variable - foo”.

NOTE: Shadowing of variables in block passed to `Ractor.new` is allowed because `Ractor` should not access outer variables. eg. following syle is encouraged:

worker_id, pipe = env
Ractor.new(worker_id, pipe) do |worker_id, pipe|
end

Examples:


# bad

def some_method
  foo = 1

  2.times do |foo| # shadowing outer `foo`
    do_something(foo)
  end
end

# good

def some_method
  foo = 1

  2.times do |bar|
    do_something(bar)
  end
end

Constant Summary collapse

MSG =
'Shadowing outer local variable - `%<variable>s`.'

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Base

#add_global_offense, #add_offense, autocorrect_incompatible_with, badge, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, #cop_name, cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, lint?, match?, #message, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #ready, #relevant_file?, support_autocorrect?, support_multiple_source?, #target_rails_version, #target_ruby_version

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #correctable?, #disable_uncorrectable?, #safe_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

silence_warnings

Constructor Details

This class inherits a constructor from RuboCop::Cop::Base

Class Method Details

.joining_forcesObject


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# File 'lib/rubocop/cop/lint/shadowing_outer_local_variable.rb', line 49

def self.joining_forces
  VariableForce
end

Instance Method Details

#before_declaring_variable(variable, variable_table) ⇒ Object


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# File 'lib/rubocop/cop/lint/shadowing_outer_local_variable.rb', line 53

def before_declaring_variable(variable, variable_table)
  return if variable.should_be_unused?
  return if ractor_block?(variable.scope.node)

  outer_local_variable = variable_table.find_variable(variable.name)
  return unless outer_local_variable

  message = format(MSG, variable: variable.name)
  add_offense(variable.declaration_node, message: message)
end