Class: RuboCop::Cop::Lint::RandOne

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

Overview

This cop checks for `rand(1)` calls. Such calls always return `0`.

Examples:


# bad

rand 1
Kernel.rand(-1)
rand 1.0
rand(-1.0)

# good

0 # just use 0 instead

Constant Summary collapse

MSG = 
'`%<method>s` always returns `0`. Perhaps you meant `rand(2)` or `rand`?'
RESTRICT_ON_SEND = 
%i[rand].freeze

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

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, joining_forces, lint?, match?, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #parse, #ready, #relevant_file?, 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?, #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_send(node) ⇒ Object 


32
33
34
35
36
 
# File 'lib/rubocop/cop/lint/rand_one.rb', line 32

def on_send(node)
  return unless rand_one?(node)

  add_offense(node)
end

#rand_one?(node) ⇒ Object 


28
29
30
 
# File 'lib/rubocop/cop/lint/rand_one.rb', line 28

def_node_matcher :rand_one?, <<~PATTERN
  (send {(const {nil? cbase} :Kernel) nil?} :rand {(int {-1 1}) (float {-1.0 1.0})})
PATTERN