Class: RuboCop::Cop::Style::FileEmpty

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector, TargetRubyVersion
Defined in:
lib/rubocop/cop/style/file_empty.rb

Overview

Prefer to use ‘File.empty?(’path/to/file’)‘ when checking if a file is empty.

Examples:

# bad
File.zero?('path/to/file')
File.size('path/to/file') == 0
File.size('path/to/file') >= 0
File.size('path/to/file').zero?
File.read('path/to/file').empty?
File.binread('path/to/file') == ''
FileTest.zero?('path/to/file')

# good
File.empty?('path/to/file')
FileTest.empty?('path/to/file')

Constant Summary collapse

MSG = 
'Use `%<file_class>s.empty?(%<arg>s)` instead.'
RESTRICT_ON_SEND = 
%i[>= != == zero? empty?].freeze

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Methods included from TargetRubyVersion

minimum_target_ruby_version, required_minimum_ruby_version, support_target_ruby_version?

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, 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

#offensive?(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/file_empty.rb', line 37

def_node_matcher :offensive?, <<~PATTERN
  {
    (send $(const {nil? cbase} {:File :FileTest}) :zero? $_)
    (send (send $(const {nil? cbase} {:File :FileTest}) :size $_) {:== :>=} (int 0))
    (send (send (send $(const {nil? cbase} {:File :FileTest}) :size $_) :!) {:== :>=} (int 0))
    (send (send $(const {nil? cbase} {:File :FileTest}) :size $_) :zero?)
    (send (send $(const {nil? cbase} {:File :FileTest}) {:read :binread} $_) {:!= :==} (str empty?))
    (send (send (send $(const {nil? cbase} {:File :FileTest}) {:read :binread} $_) :!) {:!= :==} (str empty?))
    (send (send $(const {nil? cbase} {:File :FileTest}) {:read :binread} $_) :empty?)
  }
PATTERN

#on_send(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/file_empty.rb', line 49

def on_send(node)
  offensive?(node) do |const_node, arg_node|
    add_offense(node,
                message: format(MSG, file_class: const_node.source,
                                     arg: arg_node.source)) do |corrector|
      corrector.replace(node,
                        "#{bang(node)}#{const_node.source}.empty?(#{arg_node.source})")
    end
  end
end