Class: RuboCop::Cop::Style::YodaCondition

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

Overview

Enforces or forbids Yoda conditions, i.e. comparison operations where the order of expression is reversed. eg. 5 == x

Examples:

EnforcedStyle: forbid_for_all_comparison_operators (default)

# bad
99 == foo
"bar" != foo
42 >= foo
10 < bar
99 == CONST

# good
foo == 99
foo == "bar"
foo <= 42
bar > 10
CONST == 99
"#{interpolation}" == foo
/#{interpolation}/ == foo

EnforcedStyle: forbid_for_equality_operators_only

# bad
99 == foo
"bar" != foo

# good
99 >= foo
3 < a && a < 5

EnforcedStyle: require_for_all_comparison_operators

# bad
foo == 99
foo == "bar"
foo <= 42
bar > 10

# good
99 == foo
"bar" != foo
42 >= foo
10 < bar

EnforcedStyle: require_for_equality_operators_only

# bad
99 >= foo
3 < a && a < 5

# good
99 == foo
"bar" != foo

Cop Safety Information:

  • This cop is unsafe because comparison operators can be defined differently on different classes, and are not guaranteed to have the same result if reversed.

    For example:

    class MyKlass
  def ==(other)
    true
  end
end

obj = MyKlass.new
obj == 'string'   #=> true
'string' == obj   #=> false

Constant Summary collapse

MSG = 
'Reverse the order of the operands `%<source>s`.'
REVERSE_COMPARISON = 
{ '<' => '>', '<=' => '>=', '>' => '<', '>=' => '<=' }.freeze
EQUALITY_OPERATORS = 
%i[== !=].freeze
NONCOMMUTATIVE_OPERATORS = 
%i[===].freeze
PROGRAM_NAMES = 
%i[$0 $PROGRAM_NAME].freeze
RESTRICT_ON_SEND = 
RuboCop::AST::Node::COMPARISON_OPERATORS

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

#active_support_extensions_enabled?, #add_global_offense, #add_offense, autocorrect_incompatible_with, badge, #begin_investigation, 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, #inspect, 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?, #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

#file_constant_equal_program_name?(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/yoda_condition.rb', line 90

def_node_matcher :file_constant_equal_program_name?, <<~PATTERN
  (send #source_file_path_constant? {:== :!=} (gvar #program_name?))
PATTERN

#on_send(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/yoda_condition.rb', line 94

def on_send(node)
  return unless yoda_compatible_condition?(node)
  return if (equality_only? && non_equality_operator?(node)) ||
            file_constant_equal_program_name?(node) ||
            valid_yoda?(node)

  add_offense(node) do |corrector|
    corrector.replace(actual_code_range(node), corrected_code(node))
  end
end