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Class: RuboCop::Cop::Style::DataInheritance

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
Instance Chain:
Inherits: RuboCop::Cop::Base
Defined in: lib/rubocop/cop/style/data_inheritance.rb

Overview

Checks for inheritance from Data.define to avoid creating the anonymous parent class. Inheriting from Data.define adds a superfluous level in inheritance tree.

Examples:

# bad
class Person < Data.define(:first_name, :last_name)
  def age
    42
  end
end

Person.ancestors
# => [Person, #<Class:0x000000010b4e14a0>, Data, (...)]

# good
Person = Data.define(:first_name, :last_name) do
  def age
    42
  end
end

Person.ancestors
# => [Person, Data, (...)]

Cop Safety Information:

  • Autocorrection is unsafe because it will change the inheritance tree (e.g. return value of Module#ancestors) of the constant.

    It is also unsafe because constants that the class body resolves through its ancestors (e.g. one provided by an included module) fall out of scope inside the block.

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

::RuboCop::Cop::RangeHelp - Included

BYTE_ORDER_MARK, NOT_GIVEN

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::TargetRubyVersion - Extended

::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 a 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

Reserved for Commissioner.

::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::RangeHelp - Included

#add_range,
#arguments_range

A range containing the first to the last argument of a method call or method definition.

#column_offset_between,
#contents_range

A range containing only the contents of a literal with delimiters (e.g.

#directions,
#effective_column

Returns the column attribute of the range, except if the range is on the first line and there’s a byte order mark at the beginning of that line, in which case 1 is subtracted from the column value.

#final_pos

rubocop:disable-next Metrics/ParameterLists.

#move_pos, #move_pos_str, #range_between, #range_by_whole_lines, #range_with_comments, #range_with_comments_and_lines, #range_with_surrounding_comma, #range_with_surrounding_space, #source_range

::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

 — grouped under the Commissioner heading above.

#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_gem_version

Returns a gems locked versions (i.e.

#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, #covering_disabled_range, #current_corrector,
#current_offense_locations

Reserved for Commissioner:

#current_offenses, #currently_disabled_lines, #custom_severity, #default_severity, #disable_uncorrectable, #enabled_line?,
#enabled_lines?

A multi-line offense is suppressed by a directive on any line of its range, not only its first line, matching the intuition that the directive is attached to the offending code.

#file_name_matches_any?, #find_message, #find_severity, #matches_absolute_include_pattern?, #range_for_original, #range_from_node_or_range,
#reset_investigation

Actually private methods.

#suppression_reason

The -- reason on the directive that suppresses offenses on this range, or nil when the directive carries none.

#use_corrector

::RuboCop::Cop::AutocorrectLogic - Included

::RuboCop::Cop::IgnoredNode - Included

Constructor Details

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

Instance Method Details

#correct_parent(parent, corrector) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/data_inheritance.rb', line 76

def correct_parent(parent, corrector)
  if parent.block_type?
    # Convert a brace block to `do`, so the class's own `end` closes it
    # once the closing delimiter is removed; otherwise a dangling `{` is
    # left behind, producing invalid Ruby.
    corrector.replace(parent.loc.begin, 'do') if parent.braces?
    corrector.remove(range_with_surrounding_space(parent.loc.end, newlines: false))
  elsif (class_node = parent.parent).body.nil?
    corrector.remove(range_for_empty_class_body(class_node, parent))
  else
    corrector.insert_after(parent, ' do')
  end
end

#data_define?(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/data_inheritance.rb', line 60

def_node_matcher :data_define?, <<~PATTERN
  {(send (const {nil? cbase} :Data) :define ...)
   (block (send (const {nil? cbase} :Data) :define ...) ...)}
PATTERN

#defines_constants?(class_body) ⇒ Boolean (private)

Constants, including nested classes and modules, are scoped to the class when they are defined in a class body, but leak into the enclosing namespace once moved into a Data.define block, so such a class cannot be rewritten as an assignment.

[ GitHub ]

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

def defines_constants?(class_body)
  return false unless class_body

  class_body.each_node(:casgn, :class, :module).any?
end

#on_class(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/data_inheritance.rb', line 47

def on_class(node)
  return unless data_define?(node.parent_class)
  return if defines_constants?(node.body)

  add_offense(node.parent_class) do |corrector|
    corrector.remove(range_with_surrounding_space(node.loc.keyword, newlines: false))
    corrector.replace(node.loc.operator, '=')

    correct_parent(node.parent_class, corrector)
  end
end

#range_for_empty_class_body(class_node, data_define) (private)

[ GitHub ]

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

def range_for_empty_class_body(class_node, data_define)
  if class_node.single_line?
    range_between(data_define.source_range.end_pos, class_node.source_range.end_pos)
  else
    range_by_whole_lines(class_node.loc.end, include_final_newline: true)
  end
end