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Class: RuboCop::Cop::Style::OrAssignment

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/or_assignment.rb

Overview

Checks for potential usage of the ||= operator.

Examples:

# bad
name = name ? name : 'Bozhidar'

# bad
name = if name
         name
       else
         'Bozhidar'
       end

# bad
unless name
  name = 'Bozhidar'
end

# bad
name = 'Bozhidar' unless name

# good - set name to 'Bozhidar', only if it's nil or false
name ||= 'Bozhidar'

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

Instance Method Details

#autocorrect(corrector, node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/or_assignment.rb', line 70

def autocorrect(corrector, node)
  if ternary_assignment?(node)
    variable, default = take_variable_and_default_from_ternary(node)
  else
    variable, default = take_variable_and_default_from_unless(node)
  end

  corrector.replace(node, "#{variable} ||= #{default.source}")
end

#on_cvasgn(node)

Alias for #on_lvasgn.

[ GitHub ]

  
# File 'lib/rubocop/cop/style/or_assignment.rb', line 65

alias on_cvasgn on_lvasgn

#on_gvasgn(node)

Alias for #on_lvasgn.

[ GitHub ]

  
# File 'lib/rubocop/cop/style/or_assignment.rb', line 66

alias on_gvasgn on_lvasgn

#on_if(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/or_assignment.rb', line 51

def on_if(node)
  return unless unless_assignment?(node)

  add_offense(node) { |corrector| autocorrect(corrector, node) }
end

#on_ivasgn(node)

Alias for #on_lvasgn.

[ GitHub ]

  
# File 'lib/rubocop/cop/style/or_assignment.rb', line 64

alias on_ivasgn on_lvasgn

#on_lvasgn(node) Also known as: #on_ivasgn, #on_cvasgn, #on_gvasgn

[ GitHub ]

  
# File 'lib/rubocop/cop/style/or_assignment.rb', line 57

def on_lvasgn(node)
  return unless (else_branch = ternary_assignment?(node))
  return if else_branch.if_type?

  add_offense(node) { |corrector| autocorrect(corrector, node) }
end

#take_variable_and_default_from_ternary(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/or_assignment.rb', line 80

def take_variable_and_default_from_ternary(node)
  variable, if_statement = *node
  [variable, if_statement.else_branch]
end

#take_variable_and_default_from_unless(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/or_assignment.rb', line 85

def take_variable_and_default_from_unless(node)
  if node.if_branch
    variable, default = *node.if_branch
  else
    variable, default = *node.else_branch
  end

  [variable, default]
end

#ternary_assignment?(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/or_assignment.rb', line 35

def_node_matcher :ternary_assignment?, <<~PATTERN
  ({lvasgn ivasgn cvasgn gvasgn} _var
    (if
      ({lvar ivar cvar gvar} _var)
      ({lvar ivar cvar gvar} _var)
      $_))
PATTERN

#unless_assignment?(node)

[ GitHub ]

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

def_node_matcher :unless_assignment?, <<~PATTERN
  (if
    ({lvar ivar cvar gvar} _var) nil?
    ({lvasgn ivasgn cvasgn gvasgn} _var
      _))
PATTERN