Class: RuboCop::Cop::Style::RedundantBegin

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector
Includes:
RangeHelp
Defined in:
lib/rubocop/cop/style/redundant_begin.rb

Overview

Checks for redundant ‘begin` blocks.

Currently it checks for code like this:

Examples:


# bad
def redundant
  begin
    ala
    bala
  rescue StandardError => e
    something
  end
end

# good
def preferred
  ala
  bala
rescue StandardError => e
  something
end

# bad
begin
  do_something
end

# good
do_something

# bad
# When using Ruby 2.5 or later.
do_something do
  begin
    something
  rescue => ex
    anything
  end
end

# good
# In Ruby 2.5 or later, you can omit `begin` in `do-end` block.
do_something do
  something
rescue => ex
  anything
end

# good
# Stabby lambdas don't support implicit `begin` in `do-end` blocks.
-> do
  begin
    foo
  rescue Bar
    baz
  end
end

Constant Summary collapse

MSG = 
'Redundant `begin` block detected.'

Constants included from RangeHelp

RangeHelp::BYTE_ORDER_MARK, RangeHelp::NOT_GIVEN

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Class Method Summary collapse

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Methods inherited from Base

#active_support_extensions_enabled?, #add_global_offense, #add_offense, #always_autocorrect?, 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_gem_version, #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

Class Method Details

.autocorrect_incompatible_with ⇒ Object 



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# File 'lib/rubocop/cop/style/redundant_begin.rb', line 71

def self.autocorrect_incompatible_with
  [Style::BlockDelimiters]
end

Instance Method Details

#offensive_kwbegins(node) ⇒ Object 



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

def_node_search :offensive_kwbegins, <<~PATTERN
  [(kwbegin ...) !#allowable_kwbegin?]
PATTERN

#on_block(node) ⇒ Object Also known as: on_numblock, on_itblock 



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# File 'lib/rubocop/cop/style/redundant_begin.rb', line 111

def on_block(node)
  return if target_ruby_version < 2.5
  return if node.send_node.lambda_literal?
  return if node.braces?
  return unless node.body&.kwbegin_type?

  register_offense(node.body)
end

#on_case(node) ⇒ Object Also known as: on_case_match 



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# File 'lib/rubocop/cop/style/redundant_begin.rb', line 94

def on_case(node)
  inspect_branches(node)
end

#on_def(node) ⇒ Object Also known as: on_defs 



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

def on_def(node)
  return unless node.body&.kwbegin_type?
  return if node.endless?

  register_offense(node.body)
end

#on_if(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/redundant_begin.rb', line 88

def on_if(node)
  return if node.modifier_form?

  inspect_branches(node)
end

#on_kwbegin(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/redundant_begin.rb', line 123

def on_kwbegin(node)
  return unless (target_node = offensive_kwbegins(node).to_a.last)

  register_offense(target_node)
end

#on_while(node) ⇒ Object Also known as: on_until 



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# File 'lib/rubocop/cop/style/redundant_begin.rb', line 99

def on_while(node)
  return if node.modifier_form?

  body = node.body

  return unless body&.kwbegin_type?
  return if body.rescue_node || body.ensure_node

  register_offense(body)
end