Class: RuboCop::Cop::Lint::EmptyBlock

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

Overview

Checks for blocks without a body. Such empty blocks are typically an oversight or we should provide a comment to clarify what we’re aiming for.

Empty lambdas and procs are ignored by default.

NOTE: For backwards compatibility, the configuration that allows/disallows empty lambdas and procs is called ‘AllowEmptyLambdas`, even though it also applies to procs.

Examples:

# bad
items.each { |item| }

# good
items.each { |item| puts item }

AllowComments: true (default)

# good
items.each do |item|
  # TODO: implement later (inner comment)
end

items.each { |item| } # TODO: implement later (inline comment)

AllowComments: false

# bad
items.each do |item|
  # TODO: implement later (inner comment)
end

items.each { |item| } # TODO: implement later (inline comment)

AllowEmptyLambdas: true (default)

# good
allow(subject).to receive(:callable).and_return(-> {})

placeholder = lambda do
end
(callable || placeholder).call

proc { }

Proc.new { }

AllowEmptyLambdas: false

# bad
allow(subject).to receive(:callable).and_return(-> {})

placeholder = lambda do
end
(callable || placeholder).call

proc { }

Proc.new { }

Constant Summary collapse

MSG = 
'Empty block detected.'

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

#active_support_extensions_enabled?, #add_global_offense, #add_offense, #always_autocorrect?, autocorrect_incompatible_with, badge, #begin_investigation, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #contextual_autocorrect?, #cop_config, cop_name, #cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, #inspect, joining_forces, lint?, match?, #message, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #parse, #parser_engine, #ready, #relevant_file?, requires_gem, #string_literals_frozen_by_default?, support_autocorrect?, support_multiple_source?, #target_rails_version, #target_ruby_version

Methods included from ExcludeLimit

#exclude_limit

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #autocorrect_with_disable_uncorrectable?, #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_block(node) ⇒ Object

rubocop:disable InternalAffairs/NumblockHandler



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# File 'lib/rubocop/cop/lint/empty_block.rb', line 66

def on_block(node) # rubocop:disable InternalAffairs/NumblockHandler
  return if node.body
  return if allow_empty_lambdas? && node.lambda_or_proc?
  return if cop_config['AllowComments'] && allow_comment?(node)

  add_offense(node)
end