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

Inherits:
Base
  • Object
show all
Defined in:
lib/rubocop/cop/lint/non_local_exit_from_iterator.rb

Overview

This cop 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 collapse

MSG =
'Non-local exit from iterator, without return value. ' \
'`next`, `break`, `Array#find`, `Array#any?`, etc. ' \
'is preferred.'

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods inherited from Base

#add_global_offense, #add_offense, autocorrect_incompatible_with, badge, #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, joining_forces, lint?, match?, #message, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #ready, #relevant_file?, support_autocorrect?, support_multiple_source?, #target_rails_version, #target_ruby_version

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #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

#on_return(return_node) ⇒ Object


46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
# 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