Class: RuboCop::Cop::Style::GuardClause

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector
Includes:
MinBodyLength, RangeHelp, RuboCop::Cop::StatementModifier
Defined in:
lib/rubocop/cop/style/guard_clause.rb

Overview

Use a guard clause instead of wrapping the code inside a conditional expression

A condition with an elsif or else branch is allowed unless one of return, break, next, raise, or fail is used in the body of the conditional expression.

Note
 Autocorrect works in most cases except with if-else statements that contain logical operators such as foo || raise('exception')

Examples:

# bad
def test
  if something
    work
  end
end

# good
def test
  return unless something

  work
end

# also good
def test
  work if something
end

# bad
if something
  raise 'exception'
else
  ok
end

# good
raise 'exception' if something
ok

# bad
if something
  foo || raise('exception')
else
  ok
end

# good
foo || raise('exception') if something
ok

# bad
define_method(:test) do
  if something
    work
  end
end

# good
define_method(:test) do
  return unless something

  work
end

# also good
define_method(:test) do
  work if something
end

AllowConsecutiveConditionals: false (default)

# bad
def test
  if foo?
    work
  end

  if bar?  # <- reports an offense
    work
  end
end

AllowConsecutiveConditionals: true

# good
def test
  if foo?
    work
  end

  if bar?
    work
  end
end

# bad
def test
  if foo?
    work
  end

  do_something

  if bar?  # <- reports an offense
    work
  end
end

Constant Summary collapse

MSG = 
'Use a guard clause (`%<example>s`) instead of wrapping the ' \
'code inside a conditional expression.'

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Methods inherited from Base

#active_support_extensions_enabled?, #add_global_offense, #add_offense, autocorrect_incompatible_with, badge, #begin_investigation, 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, #inspect, joining_forces, lint?, match?, #message, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #parse, #ready, #relevant_file?, 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 Also known as: on_numblock 



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# File 'lib/rubocop/cop/style/guard_clause.rb', line 132

def on_block(node)
  return unless node.method?(:define_method) || node.method?(:define_singleton_method)

  on_def(node)
end

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



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

def on_def(node)
  body = node.body

  return unless body

  check_ending_body(body)
end

#on_if(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/guard_clause.rb', line 139

def on_if(node)
  return if accepted_form?(node)

  if (guard_clause = node.if_branch&.guard_clause?)
    kw = node.loc.keyword.source
    guard = :if
  elsif (guard_clause = node.else_branch&.guard_clause?)
    kw = node.inverse_keyword
    guard = :else
  else
    return
  end

  guard = nil if and_or_guard_clause?(guard_clause)

  register_offense(node, guard_clause_source(guard_clause), kw, guard)
end