Class: RuboCop::Cop::Style::NilComparison

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

Overview

This cop checks for comparison of something with nil using `==` and `nil?`.

Supported styles are: predicate, comparison.

Examples:

EnforcedStyle: predicate (default)


# bad
if x == nil
end

# good
if x.nil?
end

EnforcedStyle: comparison


# bad
if x.nil?
end

# good
if x == nil
end

Constant Summary collapse

PREDICATE_MSG =
'Prefer the use of the `nil?` predicate.'
EXPLICIT_MSG =
'Prefer the use of the `==` comparison.'
RESTRICT_ON_SEND =
%i[== === nil?].freeze

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

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

#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

#nil_check?(node) ⇒ Object


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# File 'lib/rubocop/cop/style/nil_comparison.rb', line 44

def_node_matcher :nil_check?, '(send _ :nil?)'

#nil_comparison?(node) ⇒ Object


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# File 'lib/rubocop/cop/style/nil_comparison.rb', line 41

def_node_matcher :nil_comparison?, '(send _ {:== :===} nil)'

#on_send(node) ⇒ Object


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

def on_send(node)
  style_check?(node) do
    add_offense(node.loc.selector) do |corrector|
      new_code = if prefer_comparison?
                   node.source.sub('.nil?', ' == nil')
                 else
                   node.source.sub(/\s*={2,3}\s*nil/, '.nil?')
                 end

      corrector.replace(node, new_code)

      parent = node.parent
      corrector.wrap(node, '(', ')') if parent.respond_to?(:method?) && parent.method?(:!)
    end
  end
end