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Class: RuboCop::Cop::Lint::NonLocalExitFromIterator

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

Overview

Checks for non-local exits from iterators without a return value. It registers an offense under these conditions:

  • No value is returned,

  • the block is preceded by a method chain,

  • the block has arguments,

  • the method which receives the block is not define_method or define_singleton_method,

  • the return is not contained in an inner scope, e.g. a lambda or a method definition.

Examples:

class ItemApi
  rescue_from ValidationError do |e| # non-iteration block with arg
    return { message: 'validation error' } unless e.errors # allowed
    error_array = e.errors.map do |error| # block with method chain
      return if error.suppress? # warned
      return "#{error.param}: invalid" unless error.message # allowed
      "#{error.param}: #{error.message}"
    end
    { message: 'validation error', errors: error_array }
  end

  def update_items
    transaction do # block without arguments
      return unless update_necessary? # allowed
      find_each do |item| # block without method chain
        return if item.stock == 0 # false-negative...
        item.update!(foobar: true)
      end
    end
  end
end

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

Class Attribute Summary

::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

#chained_send?(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/non_local_exit_from_iterator.rb', line 77

def_node_matcher :chained_send?, '(send !nil? ...)'

#define_method?(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/non_local_exit_from_iterator.rb', line 80

def_node_matcher :define_method?, <<~PATTERN
  (send _ {:define_method :define_singleton_method} _)
PATTERN

#on_return(return_node)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/non_local_exit_from_iterator.rb', line 46

def on_return(return_node)
  return if return_value?(return_node)

  return_node.each_ancestor(:block, :def, :defs) do |node|
    break if scoped_node?(node)

    # if a proc is passed to `Module#define_method` or
    # `Object#define_singleton_method`, `return` will not cause a
    # non-local exit error
    break if define_method?(node.send_node)

    next unless node.arguments?

    if chained_send?(node.send_node)
      add_offense(return_node.loc.keyword)
      break
    end
  end
end

#return_value?(return_node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/non_local_exit_from_iterator.rb', line 72

def return_value?(return_node)
  !return_node.children.empty?
end

#scoped_node?(node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/non_local_exit_from_iterator.rb', line 68

def scoped_node?(node)
  node.def_type? || node.defs_type? || node.lambda?
end