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Class: RuboCop::Cop::Style::MissingElse

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/missing_else.rb

Overview

Checks for if expressions that do not have an else branch.

Note
Pattern matching is allowed to have no else branch because unlike if and case, it raises NoMatchingPatternError if the pattern doesn’t match and without having else.

Supported styles are: if, case, both.

Examples:

EnforcedStyle: both (default)

# warn when an `if` or `case` expression is missing an `else` branch.

# bad
if condition
  statement
end

# bad
case var
when condition
  statement
end

# good
if condition
  statement
else
  # the content of `else` branch will be determined by Style/EmptyElse
end

# good
case var
when condition
  statement
else
  # the content of `else` branch will be determined by Style/EmptyElse
end

EnforcedStyle: if

# warn when an `if` expression is missing an `else` branch.

# bad
if condition
  statement
end

# good
if condition
  statement
else
  # the content of `else` branch will be determined by Style/EmptyElse
end

# good
case var
when condition
  statement
end

# good
case var
when condition
  statement
else
  # the content of `else` branch will be determined by Style/EmptyElse
end

EnforcedStyle: case

# warn when a `case` expression is missing an `else` branch.

# bad
case var
when condition
  statement
end

# good
case var
when condition
  statement
else
  # the content of `else` branch will be determined by Style/EmptyElse
end

# good
if condition
  statement
end

# good
if condition
  statement
else
  # the content of `else` branch will be determined by Style/EmptyElse
end

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

::RuboCop::Cop::ConfigurableEnforcedStyle - Included

SYMBOL_TO_STRING_CACHE

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.

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

Returns an url to view this cops documentation online.

.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::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

Actually private methods.

#use_corrector

::RuboCop::Cop::AutocorrectLogic - Included

::RuboCop::Cop::IgnoredNode - Included

Constructor Details

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

Instance Attribute Details

#case_style?Boolean (readonly, private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/missing_else.rb', line 159

def case_style?
  style == :case
end

#empty_else_cop_enabled?Boolean (readonly, private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/missing_else.rb', line 171

def empty_else_cop_enabled?
  empty_else_config.fetch('Enabled')
end

#if_style?Boolean (readonly, private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/missing_else.rb', line 155

def if_style?
  style == :if
end

#unless_else_cop_enabled?Boolean (readonly, private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/missing_else.rb', line 163

def unless_else_cop_enabled?
  unless_else_config.fetch('Enabled')
end

Instance Method Details

#autocorrect(corrector, node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/missing_else.rb', line 146

def autocorrect(corrector, node)
  case empty_else_style
  when :empty
    corrector.insert_before(node.loc.end, 'else; nil; ')
  when :nil
    corrector.insert_before(node.loc.end, 'else; ')
  end
end

#check(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/missing_else.rb', line 127

def check(node)
  return if node.else?

  add_offense(node, message: format(message_template, type: node.type)) do |corrector|
    autocorrect(corrector, node)
  end
end

#empty_else_config (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/missing_else.rb', line 181

def empty_else_config
  config.for_cop('Style/EmptyElse')
end

#empty_else_style (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/missing_else.rb', line 175

def empty_else_style
  return unless empty_else_config.key?('EnforcedStyle')

  empty_else_config['EnforcedStyle'].to_sym
end

#message_template (private)

[ GitHub ]

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

def message_template
  case empty_else_style
  when :empty
    MSG_NIL
  when :nil
    MSG_EMPTY
  else
    MSG
  end
end

#on_case(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/missing_else.rb', line 115

def on_case(node)
  return if if_style?

  check(node)
end

#on_case_match(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/missing_else.rb', line 121

def on_case_match(node)
  # do nothing.
end

#on_normal_if_unless(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/missing_else.rb', line 108

def on_normal_if_unless(node)
  return if case_style?
  return if unless_else_cop_enabled? && node.unless?

  check(node)
end

#unless_else_config (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/missing_else.rb', line 167

def unless_else_config
  config.for_cop('Style/UnlessElse')
end