Class: RuboCop::Cop::Style::RandomWithOffset

Inherits:
Cop
  • Object
show all
Defined in:
lib/rubocop/cop/style/random_with_offset.rb

Overview

This cop checks for the use of randomly generated numbers, added/subtracted with integer literals, as well as those with Integer#succ and Integer#pred methods. Prefer using ranges instead, as it clearly states the intentions.

Examples:

# bad
rand(6) + 1
1 + rand(6)
rand(6) - 1
1 - rand(6)
rand(6).succ
rand(6).pred
Random.rand(6) + 1
Kernel.rand(6) + 1
rand(0..5) + 1

# good
rand(1..6)
rand(1...7)

Constant Summary collapse

MSG = 
'Prefer ranges when generating random numbers instead of ' \
'integers with offsets.'.freeze

Constants included from Util

Util::ASGN_NODES, Util::BYTE_ORDER_MARK, Util::CONDITIONAL_NODES, Util::EQUALS_ASGN_NODES, Util::LITERAL_REGEX, Util::LOGICAL_OPERATOR_NODES, Util::MODIFIER_NODES, Util::OPERATOR_METHODS, Util::SHORTHAND_ASGN_NODES

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

Methods inherited from Cop

#add_offense, all, autocorrect_incompatible_with, badge, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, cop_name, #cop_name, #correct, department, #duplicate_location?, #excluded_file?, #find_location, #highlights, inherited, #initialize, #join_force?, lint?, match?, #message, #messages, non_rails, #parse, qualified_cop_name, #relevant_file?, #target_rails_version, #target_ruby_version

Methods included from AST::Sexp

#s

Methods included from NodePattern::Macros

#def_node_matcher, #def_node_search, #node_search, #node_search_all, #node_search_body, #node_search_first

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #support_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

begins_its_line?, comment_line?, double_quotes_required?, effective_column, ends_its_line?, escape_string, first_part_of_call_chain, interpret_string_escapes, line_range, needs_escaping?, on_node, operator?, parentheses?, parenthesized_call?, precede?, range_between, range_by_whole_lines, range_with_surrounding_comma, range_with_surrounding_space, same_line?, source_range, strip_quotes, stripped_source_upto, symbol_without_quote?, to_string_literal, to_supported_styles, to_symbol_literal, within_node?

Methods included from PathUtil

absolute?, find_file_upwards, match_path?, pwd, relative_path, reset_pwd, smart_path

Constructor Details

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

Instance Method Details

#autocorrect(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/random_with_offset.rb', line 65

def autocorrect(node)
  lambda do |corrector|
    if integer_op_rand?(node)
      corrector.replace(node.source_range,
                        corrected_integer_op_rand(node))
    elsif rand_op_integer?(node)
      corrector.replace(node.source_range,
                        corrected_rand_op_integer(node))
    elsif rand_modified?(node)
      corrector.replace(node.source_range,
                        corrected_rand_modified(node))
    end
  end
end

#on_send(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/random_with_offset.rb', line 58

def on_send(node)
  return unless integer_op_rand?(node) ||
                rand_op_integer?(node) ||
                rand_modified?(node)
  add_offense(node)
end