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Class: RuboCop::Cop::Style::SelfAssignment

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, ::RuboCop::Cop::AutoCorrector, ::RuboCop::Cop::Base, ::RuboCop::ExcludeLimit, NodePattern::Macros, RuboCop::AST::Sexp
Instance Chain:
Inherits: RuboCop::Cop::Base
Defined in: lib/rubocop/cop/style/self_assignment.rb

Overview

Enforces the use the shorthand for self-assignment.

Examples:

# bad
x = x + 1

# good
x += 1

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

Class Attribute Summary

::RuboCop::Cop::AutoCorrector - Extended

::RuboCop::Cop::Base - Inherited

.gem_requirements, .lint?,
.support_autocorrect?

Returns if class supports autocorrect.

.support_multiple_source?

Override if your cop should be called repeatedly for multiple investigations Between calls to on_new_investigation and on_investigation_end, the result of processed_source will remain constant.

Class Method Summary

::RuboCop::Cop::Base - Inherited

.autocorrect_incompatible_with

List of cops that should not try to autocorrect at the same time as this cop.

.badge

Naming.

.callbacks_needed, .cop_name, .department,
.documentation_url

Returns an url to view this cops documentation online.

.exclude_from_registry

Call for abstract Cop classes.

.inherited,
.joining_forces

Override and return the Force class(es) you need to join.

.match?

Returns true if the cop name or the cop namespace matches any of the given names.

.new,
.requires_gem

Register a version requirement for the given gem name.

.restrict_on_send

::RuboCop::ExcludeLimit - Extended

exclude_limit

Sets up a configuration option to have an exclude limit tracked.

transform

Instance Attribute Summary

Instance Method Summary

::RuboCop::Cop::Base - Inherited

#add_global_offense

Adds an offense that has no particular location.

#add_offense

Adds an offense on the specified range (or node with an expression) Unless that offense is disabled for this range, a corrector will be yielded to provide the cop the opportunity to autocorrect the offense.

#begin_investigation

Called before any investigation.

#callbacks_needed,
#cop_config

Configuration Helpers.

#cop_name, #excluded_file?,
#external_dependency_checksum

This method should be overridden when a cop’s behavior depends on state that lives outside of these locations:

#inspect
#message

Gets called if no message is specified when calling add_offense or add_global_offense Cops are discouraged to override this; instead pass your message directly.

#name

Alias for Base#cop_name.

#offenses,
#on_investigation_end

Called after all on_…​

#on_new_investigation

Called before all on_…​

#on_other_file

Called instead of all on_…​

#parse

There should be very limited reasons for a Cop to do it’s own parsing.

#parser_engine,
#ready

Called between investigations.

#relevant_file?, #target_rails_version, #target_ruby_version, #annotate, #apply_correction, #attempt_correction,
#callback_argument

Reserved for Cop::Cop.

#complete_investigation

Called to complete an investigation.

#correct, #current_corrector,
#current_offense_locations

Reserved for Commissioner:

#current_offenses, #currently_disabled_lines, #custom_severity, #default_severity, #disable_uncorrectable, #enabled_line?, #file_name_matches_any?, #find_message, #find_severity, #range_for_original, #range_from_node_or_range,
#reset_investigation

Actually private methods.

#use_corrector

::RuboCop::Cop::AutocorrectLogic - Included

::RuboCop::Cop::IgnoredNode - Included

Constructor Details

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

Class Method Details

.autocorrect_incompatible_with

[ GitHub ]

  
# File 'lib/rubocop/cop/style/self_assignment.rb', line 21

def self.autocorrect_incompatible_with
  [Layout::SpaceAroundOperators]
end

Instance Method Details

#apply_autocorrect(corrector, node, rhs, operator, new_rhs) (private)

[ GitHub ]

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

def apply_autocorrect(corrector, node, rhs, operator, new_rhs)
  corrector.insert_before(node.loc.operator, operator)
  corrector.replace(rhs, new_rhs.source)
end

#autocorrect(corrector, node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/self_assignment.rb', line 74

def autocorrect(corrector, node)
  _var_name, rhs = *node

  if rhs.send_type?
    autocorrect_send_node(corrector, node, rhs)
  elsif rhs.operator_keyword?
    autocorrect_boolean_node(corrector, node, rhs)
  end
end

#autocorrect_boolean_node(corrector, node, rhs) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/self_assignment.rb', line 89

def autocorrect_boolean_node(corrector, node, rhs)
  _first_operand, second_operand = *rhs
  apply_autocorrect(corrector, node, rhs, rhs.loc.operator.source, second_operand)
end

#autocorrect_send_node(corrector, node, rhs) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/self_assignment.rb', line 84

def autocorrect_send_node(corrector, node, rhs)
  _receiver, method_name, args = *rhs
  apply_autocorrect(corrector, node, rhs, method_name.to_s, args)
end

#check(node, var_type) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/self_assignment.rb', line 39

def check(node, var_type)
  var_name, rhs = *node
  return unless rhs

  if rhs.send_type?
    check_send_node(node, rhs, var_name, var_type)
  elsif rhs.operator_keyword?
    check_boolean_node(node, rhs, var_name, var_type)
  end
end

#check_boolean_node(node, rhs, var_name, var_type) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/self_assignment.rb', line 62

def check_boolean_node(node, rhs, var_name, var_type)
  first_operand, _second_operand = *rhs

  target_node = s(var_type, var_name)
  return unless first_operand == target_node

  operator = rhs.loc.operator.source
  add_offense(node, message: format(MSG, method: operator)) do |corrector|
    autocorrect(corrector, node)
  end
end

#check_send_node(node, rhs, var_name, var_type) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/self_assignment.rb', line 50

def check_send_node(node, rhs, var_name, var_type)
  receiver, method_name, *_args = *rhs
  return unless OPS.include?(method_name)

  target_node = s(var_type, var_name)
  return unless receiver == target_node

  add_offense(node, message: format(MSG, method: method_name)) do |corrector|
    autocorrect(corrector, node)
  end
end

#on_cvasgn(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/self_assignment.rb', line 33

def on_cvasgn(node)
  check(node, :cvar)
end

#on_ivasgn(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/self_assignment.rb', line 29

def on_ivasgn(node)
  check(node, :ivar)
end

#on_lvasgn(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/self_assignment.rb', line 25

def on_lvasgn(node)
  check(node, :lvar)
end