Class: RuboCop::Cop::Lint::SafeNavigationWithEmpty

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector
Defined in:
lib/rubocop/cop/lint/safe_navigation_with_empty.rb

Overview

Checks to make sure safe navigation isn’t used with ‘empty?` in a conditional.

While the safe navigation operator is generally a good idea, when checking ‘foo&.empty?` in a conditional, `foo` being `nil` will actually do the opposite of what the author intends.

Examples:

# bad
return if foo&.empty?
return unless foo&.empty?

# good
return if foo && foo.empty?
return unless foo && foo.empty?

Constant Summary collapse

MSG = 
'Avoid calling `empty?` with the safe navigation operator in conditionals.'

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Methods inherited from Base

#active_support_extensions_enabled?, #add_global_offense, #add_offense, #always_autocorrect?, autocorrect_incompatible_with, badge, #begin_investigation, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #contextual_autocorrect?, #cop_config, cop_name, #cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, #inspect, joining_forces, lint?, match?, #message, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #parse, #parser_engine, #ready, #relevant_file?, requires_gem, #string_literals_frozen_by_default?, support_autocorrect?, support_multiple_source?, #target_rails_version, #target_ruby_version

Methods included from ExcludeLimit

#exclude_limit

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #autocorrect_with_disable_uncorrectable?, #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

Instance Method Details

#on_if(node) ⇒ Object 



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# File 'lib/rubocop/cop/lint/safe_navigation_with_empty.rb', line 32

def on_if(node)
  return unless safe_navigation_empty_in_conditional?(node)

  condition = node.condition

  add_offense(condition) do |corrector|
    receiver = condition.receiver.source

    corrector.replace(condition, "#{receiver} && #{receiver}.#{condition.method_name}")
  end
end

#safe_navigation_empty_in_conditional?(node) ⇒ Object 



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# File 'lib/rubocop/cop/lint/safe_navigation_with_empty.rb', line 28

def_node_matcher :safe_navigation_empty_in_conditional?, <<~PATTERN
  (if (csend (send ...) :empty?) ...)
PATTERN