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Class: RuboCop::Cop::Style::EmptyElse

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

Overview

Checks for empty else-clauses, possibly including comments and/or an explicit nil depending on the EnforcedStyle.

Examples:

EnforcedStyle: both (default)

# warn on empty else and else with nil in it

# bad
if condition
  statement
else
  nil
end

# bad
if condition
  statement
else
end

# good
if condition
  statement
else
  statement
end

# good
if condition
  statement
end

EnforcedStyle: empty

# warn only on empty else

# bad
if condition
  statement
else
end

# good
if condition
  statement
else
  nil
end

# good
if condition
  statement
else
  statement
end

# good
if condition
  statement
end

EnforcedStyle: nil

# warn on else with nil in it

# bad
if condition
  statement
else
  nil
end

# good
if condition
  statement
else
end

# good
if condition
  statement
else
  statement
end

# good
if condition
  statement
end

AllowComments: false (default)

# bad
if condition
  statement
else
  # something comment
  nil
end

# bad
if condition
  statement
else
  # something comment
end

AllowComments: true

# good
if condition
  statement
else
  # something comment
  nil
end

# good
if condition
  statement
else
  # something comment
end

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

::RuboCop::Cop::ConfigurableEnforcedStyle - Included

SYMBOL_TO_STRING_CACHE

::RuboCop::Cop::RangeHelp - Included

BYTE_ORDER_MARK, NOT_GIVEN

Class Attribute Summary

::RuboCop::Cop::AutoCorrector - Extended

::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.

.builtin?

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

Cops (other than builtin) are encouraged to implement this.

.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::RangeHelp - Included

#add_range, #column_offset_between,
#contents_range

A range containing only the contents of a literal with delimiters (e.g.

#directions,
#effective_column

Returns the column attribute of the range, except if the range is on the first line and there’s a byte order mark at the beginning of that line, in which case 1 is subtracted from the column value.

#final_pos, #move_pos, #move_pos_str, #range_between, #range_by_whole_lines, #range_with_comments, #range_with_comments_and_lines, #range_with_surrounding_comma, #range_with_surrounding_space, #source_range

::RuboCop::Cop::ConfigurableEnforcedStyle - Included

::RuboCop::Cop::OnNormalIfUnless - Included

::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, #use_corrector

::RuboCop::Cop::AutocorrectLogic - Included

::RuboCop::Cop::IgnoredNode - Included

Constructor Details

This class inherits a constructor from RuboCop::Cop::Base

Instance Attribute Details

#empty_style?Boolean (readonly, private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/empty_else.rb', line 156

def empty_style?
  style == :empty || style == :both
end

#nil_style?Boolean (readonly, private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/empty_else.rb', line 152

def nil_style?
  style == :nil || style == :both
end

Instance Method Details

#autocorrect(corrector, node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/empty_else.rb', line 172

def autocorrect(corrector, node)
  return false if autocorrect_forbidden?(node.type.to_s)
  return false if comment_in_else?(node.loc)

  end_pos = base_node(node).loc.end.begin_pos
  corrector.remove(range_between(node.loc.else.begin_pos, end_pos))
end

#autocorrect_forbidden?(type) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/empty_else.rb', line 193

def autocorrect_forbidden?(type)
  [type, 'both'].include?(missing_else_style)
end

#base_node(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/empty_else.rb', line 186

def base_node(node)
  return node if node.case_type?
  return node unless node.elsif?

  node.each_ancestor(:if, :case, :when).find(-> { node }) { |parent| parent.loc.end }
end

#check(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/empty_else.rb', line 145

def check(node)
  return if cop_config['AllowComments'] && comment_in_else?(node.loc)

  empty_check(node) if empty_style?
  nil_check(node) if nil_style?
end

#comment_in_else?(loc) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/empty_else.rb', line 180

def comment_in_else?(loc)
  return false if loc.else.nil? || loc.end.nil?

  processed_source.contains_comment?(loc.else.join(loc.end))
end

#empty_check(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/empty_else.rb', line 160

def empty_check(node)
  return unless node.else? && !node.else_branch

  add_offense(node.loc.else) { |corrector| autocorrect(corrector, node) }
end

#missing_else_style (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/empty_else.rb', line 197

def missing_else_style
  missing_cfg = config.for_cop('Style/MissingElse')
  missing_cfg.fetch('Enabled') ? missing_cfg['EnforcedStyle'] : nil
end

#nil_check(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/empty_else.rb', line 166

def nil_check(node)
  return unless node.else_branch&.nil_type?

  add_offense(node.loc.else) { |corrector| autocorrect(corrector, node) }
end

#on_case(node)

[ GitHub ]

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

def on_case(node)
  check(node)
end

#on_normal_if_unless(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/empty_else.rb', line 135

def on_normal_if_unless(node)
  check(node)
end