Class: RuboCop::Cop::Style::ReturnNil

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

Overview

Enforces consistency between return nil and return.

This cop is disabled by default. Because there seems to be a perceived semantic difference between return and return nil. The former can be seen as just halting evaluation, while the latter might be used when the return value is of specific concern.

Supported styles are return and return_nil.

Examples:

EnforcedStyle: return (default)

# bad
def foo(arg)
  return nil if arg
end

# good
def foo(arg)
  return if arg
end

EnforcedStyle: return_nil

# bad
def foo(arg)
  return if arg
end

# good
def foo(arg)
  return nil if arg
end

Constant Summary collapse

RETURN_MSG = 
'Use `return` instead of `return nil`.'
RETURN_NIL_MSG = 
'Use `return nil` instead of `return`.'

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source, #project_index

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Methods included from ConfigurableEnforcedStyle

#alternative_style, #alternative_styles, #ambiguous_style_detected, #correct_style_detected, #detected_style, #detected_style=, #no_acceptable_style!, #no_acceptable_style?, #opposite_style_detected, #style, #style_configured?, #style_detected, #style_parameter_name, #supported_styles, #unexpected_style_detected

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?, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #parse, #parser_engine, #ready, #relevant_file?, requires_gem, #string_literals_frozen_by_default?, support_autocorrect?, support_multiple_source?, #target_gem_version, #target_rails_version, #target_ruby_version

Methods included from ExcludeLimit

cop_dir_for, #exclude_limit, read_limits

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

#on_return(node) ⇒ Object 



48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
 
# File 'lib/rubocop/cop/style/return_nil.rb', line 48

def on_return(node)
  # Check Lint/NonLocalExitFromIterator first before this cop
  node.each_ancestor(:block, :any_def) do |n|
    break if scoped_node?(n)

    send_node, args_node, _body_node = *n

    # if a proc is passed to `Module#define_method` or
    # `Object#define_singleton_method`, `return` will not cause a
    # non-local exit error
    break if define_method?(send_node)

    next if args_node.children.empty?

    return nil if chained_send?(send_node)
  end

  return if correct_style?(node)

  add_offense(node) do |corrector|
    corrected = style == :return ? 'return' : 'return nil'

    corrector.replace(node, corrected)
  end
end

#return_nil_node?(node) ⇒ Object 



46
 
# File 'lib/rubocop/cop/style/return_nil.rb', line 46

def_node_matcher :return_nil_node?, '(return nil)'

#return_node?(node) ⇒ Object 



43
 
# File 'lib/rubocop/cop/style/return_nil.rb', line 43

def_node_matcher :return_node?, '(return)'