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

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

Overview

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

With ‘IncludeSemanticChanges` set to `false` by default, this cop does not report offenses for `!x.nil?` and does no changes that might change behavior.

With ‘IncludeSemanticChanges` set to `true`, this cop reports offenses for `!x.nil?` and autocorrects that and `x != nil` to solely `x`, which is usually OK, but might change behavior.

Examples:

# bad
if x != nil
end

# good
if x
end

# Non-nil checks are allowed if they are the final nodes of predicate.
# good
def signed_in?
  !current_user.nil?
end

IncludeSemanticChanges: false (default)

# good
if !x.nil?
end

IncludeSemanticChanges: true

# bad
if !x.nil?
end

Constant Summary collapse

RESTRICT_ON_SEND = 
i[!= nil? !].freeze

Constants included from Util

Util::LITERAL_REGEX

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

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, #ready, #relevant_file?, support_autocorrect?, support_multiple_source?, #target_rails_version, #target_ruby_version

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

add_parentheses, args_begin, args_end, begins_its_line?, comment_line?, comment_lines?, double_quotes_required?, escape_string, first_part_of_call_chain, indent, interpret_string_escapes, line_range, needs_escaping?, on_node, parentheses?, same_line?, to_string_literal, to_supported_styles, trim_string_interporation_escape_character

Methods included from PathUtil

absolute?, hidden_dir?, hidden_file?, hidden_file_in_not_hidden_dir?, match_path?, maybe_hidden_file?, relative_path, smart_path

Constructor Details

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

Instance Method Details

#on_def(node) ⇒ Object Also known as: on_defs 



61
62
63
64
65
66
67
68
69
70
71
 
# File 'lib/rubocop/cop/style/non_nil_check.rb', line 61

def on_def(node)
  body = node.body

  return unless node.predicate_method? && body

  if body.begin_type?
    ignore_node(body.children.last)
  else
    ignore_node(body)
  end
end

#on_send(node) ⇒ Object 



51
52
53
54
55
56
57
58
59
 
# File 'lib/rubocop/cop/style/non_nil_check.rb', line 51

def on_send(node)
  return if ignored_node?(node)
  return unless (offense_node = find_offense_node(node))

  message = message(node)
  add_offense(offense_node, message: message) do |corrector|
    autocorrect(corrector, node)
  end
end