Class: RuboCop::Cop::Style::NumericPredicate

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

Overview

This cop checks for usage of comparison operators (`==`, `>`, `<`) to test numbers as zero, positive, or negative. These can be replaced by their respective predicate methods. The cop can also be configured to do the reverse.

The cop disregards `#nonzero?` as its value is truthy or falsey, but not `true` and `false`, and thus not always interchangeable with `!= 0`.

The cop ignores comparisons to global variables, since they are often populated with objects which can be compared with integers, but are not themselves `Integer` polymorphic.

Examples:

EnforcedStyle: predicate (default)

# bad

foo == 0
0 > foo
bar.baz > 0

# good

foo.zero?
foo.negative?
bar.baz.positive?

EnforcedStyle: comparison

# bad

foo.zero?
foo.negative?
bar.baz.positive?

# good

foo == 0
0 > foo
bar.baz > 0

Constant Summary collapse

MSG = 
'Use `%<prefer>s` instead of `%<current>s`.'
REPLACEMENTS = 
{
  'zero?' => '==',
  'positive?' => '>',
  'negative?' => '<'
}.freeze
RESTRICT_ON_SEND = 
%i[== > < positive? negative? zero?].freeze

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Methods included from IgnoredMethods

#ignored_method?, #ignored_methods, included

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?, #message, #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 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

#on_send(node) ⇒ Object 


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# File 'lib/rubocop/cop/style/numeric_predicate.rb', line 59

def on_send(node)
  numeric, replacement = check(node)
  return unless numeric

  return if ignored_method?(node.method_name) ||
            node.each_ancestor(:send, :block).any? do |ancestor|
              ignored_method?(ancestor.method_name)
            end

  message = format(MSG, prefer: replacement, current: node.source)
  add_offense(node, message: message) do |corrector|
    corrector.replace(node, replacement)
  end
end