Class: RuboCop::Cop::Style::NonNilCheck

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

Overview

This cop checks for non-nil checks, which are usually redundant.

Non-nil checks are allowed if they are the final nodes of predicate.

# good
def signed_in?
  !current_user.nil?
end

Examples:


# bad
if x != nil

# good (when not allowing semantic changes)
# bad (when allowing semantic changes)
if !x.nil?

# good (when allowing semantic changes)
if x

Constant Summary

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 included from OnMethodDef

#method_def_node_parts, #on_def, #on_defs

Methods inherited from Cop

#add_offense, all, 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?, #messages, non_rails, #parse, qualified_cop_name, #relevant_file?, #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?, block_length, comment_line?, compatible_external_encoding_for?, directions, double_quotes_acceptable?, double_quotes_required?, effective_column, ends_its_line?, escape_string, first_part_of_call_chain, hard_to_type?, interpret_string_escapes, line_distance, line_range, move_pos, needs_escaping?, numeric_range_size, on_node, operator?, parentheses?, parenthesized_call?, preceed?, range_between, range_with_surrounding_comma, range_with_surrounding_space, same_line?, source_range, strip_quotes, stripped_source_upto, to_string_literal, to_supported_styles, to_symbol_literal, within_node?

Methods included from PathUtil

absolute?, match_path?, relative_path

Constructor Details

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

Instance Method Details

#on_send(node) ⇒ Object 



34
35
36
37
38
39
40
41
42
43
 
# File 'lib/rubocop/cop/style/non_nil_check.rb', line 34

def on_send(node)
  return if ignored_node?(node)

  if not_equal_to_nil?(node)
    add_offense(node, :selector)
  elsif include_semantic_changes? &&
        (not_and_nil_check?(node) || unless_and_nil_check?(node))
    add_offense(node, :expression)
  end
end