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Class: RuboCop::Cop::Lint::EmptyConditionalBody

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:
self, ::RuboCop::Cop::RangeHelp, ::RuboCop::Cop::CommentsHelp, ::RuboCop::Cop::Base, ::RuboCop::Cop::AutocorrectLogic, ::RuboCop::Cop::IgnoredNode, ::RuboCop::Util, RuboCop::AST::Sexp
Inherits: RuboCop::Cop::Base
Defined in: lib/rubocop/cop/lint/empty_conditional_body.rb

Overview

Checks for the presence of if, elsif and unless branches without a body.

Note
 empty else branches are handled by Style/EmptyElse.

Examples:

# bad
if condition
end

# bad
unless condition
end

# bad
if condition
  do_something
elsif other_condition
end

# good
if condition
  do_something
end

# good
unless condition
  do_something
end

# good
if condition
  do_something
elsif other_condition
  do_something_else
end

AllowComments: true (default)

# good
if condition
  do_something
elsif other_condition
  # noop
end

AllowComments: false

# bad
if condition
  do_something
elsif other_condition
  # noop
end

Cop Safety Information:

  • Autocorrection for this cop is not safe. The conditions for empty branches that the autocorrection removes may have side effects, or the logic in subsequent branches may change due to the removal of a previous condition.

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

::RuboCop::Cop::RangeHelp - Included

BYTE_ORDER_MARK, NOT_GIVEN

Class Attribute Summary

::RuboCop::Cop::AutoCorrector - Extended

support_autocorrect?

::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 a 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

::RuboCop::Cop::Base - Inherited

#active_support_extensions_enabled?, #always_autocorrect?, #config, #config_to_allow_offenses, #config_to_allow_offenses=, #contextual_autocorrect?, #processed_source, #string_literals_frozen_by_default?, #target_satisfies_all_gem_version_requirements?

::RuboCop::Cop::AutocorrectLogic - Included

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #autocorrect_with_disable_uncorrectable?, #correctable?, #disable_uncorrectable?, #safe_autocorrect?

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::CommentsHelp - Included

#comments_contain_disables?, #comments_in_range, #contains_comments?, #source_range_with_comment, #begin_pos_with_comment, #buffer, #end_position_for,
#find_end_line

Returns the end line of a node, which might be a comment and not part of the AST End line is considered either the line at which another node starts, or the line at which the parent node ends.
#start_line_position

::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

#disable_offense, #disable_offense_at_end_of_line, #disable_offense_before_and_after, #disable_offense_with_eol_or_surround_comment, #max_line_length,
#range_by_lines

Expand the given range to include all of any lines it covers.
#range_of_first_line, #range_overlaps_offense?, #string_continuation, #string_continuation?, #surrounding_heredoc, #surrounding_percent_array

::RuboCop::Cop::IgnoredNode - Included

#ignore_node, #ignored_node?, #part_of_ignored_node?, #ignored_nodes

Constructor Details

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

Instance Method Details

#all_branches_body_missing?(node) ⇒ Boolean (private)

[ GitHub ] 

  


# File 'lib/rubocop/cop/lint/empty_conditional_body.rb', line 177



def all_branches_body_missing?(node)
  return false unless node.parent&.if_type?

  node.parent.branches.compact.empty?
end


  








  

    #autocorrect(corrector, node)   (private)
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/empty_conditional_body.rb', line 95



def autocorrect(corrector, node)
  remove_comments(corrector, node)
  remove_empty_branch(corrector, node)
  correct_other_branches(corrector, node)
end


  








  

    #branch_range(node)   (private)
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/empty_conditional_body.rb', line 163



def branch_range(node)
  if empty_if_branch?(node) && else_branch?(node)
    node.source_range.with(end_pos: node.loc.else.begin_pos)
  elsif node.loc.else
    node.source_range.with(end_pos: node.condition.source_range.end_pos)
  elsif all_branches_body_missing?(node)
    if_node = node.ancestors.detect(&:if?)
    node.source_range.join(if_node.loc.end.end)
  else
    node.source_range
  end
end


  








  

    #correct_other_branches(corrector, node)   (private)
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/empty_conditional_body.rb', line 125



def correct_other_branches(corrector, node)
  return unless require_other_branches_correction?(node)

  if node.else_branch&.if_type? && !node.else_branch.modifier_form?
    # Replace an orphaned `elsif` with `if`
    corrector.replace(node.else_branch.loc.keyword, 'if')
  else
    # Flip orphaned `else`
    corrector.replace(node.loc.else, "#{node.inverse_keyword} #{node.condition.source}")
  end
end


  








  

    #deletion_range(range)   (private)
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/empty_conditional_body.rb', line 183



def deletion_range(range)
  # Collect a range between the start of the `if` node and the next relevant node,
  # including final new line.
  # Based on `RangeHelp#range_by_whole_lines` but allows the `if` to not start
  # on the first column.
  buffer = @processed_source.buffer

  last_line = buffer.source_line(range.last_line)
  end_offset = last_line.length - range.last_column + 1

  range.adjust(end_pos: end_offset).intersect(buffer.source_range)
end


  








  

    #else_branch?(node)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/empty_conditional_body.rb', line 158



def else_branch?(node)
  node.else_branch && !node.else_branch.if_type?
end


  








  

    #empty_elsif_branch?(node)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/empty_conditional_body.rb', line 152



def empty_elsif_branch?(node)
  return false unless (else_branch = node.else_branch)

  else_branch.if_type? && !else_branch.body
end


  








  

    #empty_if_branch?(node)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/empty_conditional_body.rb', line 144



def empty_if_branch?(node)
  return false unless (parent = node.parent)
  return true unless parent.if_type?
  return true unless (if_branch = parent.if_branch)

  if_branch.if_type? && !if_branch.body
end


  








  

    #offense_range(node)   (private)
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/empty_conditional_body.rb', line 87



def offense_range(node)
  if node.loc.else
    node.source_range.begin.join(node.loc.else.begin)
  else
    node.source_range
  end
end


  








  

    #on_if(node)  
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/empty_conditional_body.rb', line 71



def on_if(node)
  return if node.body || same_line?(node.loc.begin, node.loc.end)
  return if cop_config['AllowComments'] && contains_comments?(node)

  range = offense_range(node)

  add_offense(range, message: format(MSG, keyword: node.keyword)) do |corrector|
    next if node.parent&.call_type?

    autocorrect(corrector, node)
  end
end


  








  

    #remove_comments(corrector, node)   (private)
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/empty_conditional_body.rb', line 101



def remove_comments(corrector, node)
  comments_in_range(node).each do |comment|
    range = range_by_whole_lines(comment.source_range, include_final_newline: true)
    corrector.remove(range)
  end
end


  








  

    #remove_empty_branch(corrector, node)   (private)
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/empty_conditional_body.rb', line 109



def remove_empty_branch(corrector, node)
  range = if empty_if_branch?(node) && else_branch?(node)
            branch_range(node)
          elsif same_line?(node, else_kw_loc = node.loc.else)
            node.source_range.begin.join(else_kw_loc.begin)
          elsif node.parent&.loc.respond_to?(:end) &&
                same_line?(node, end_loc = node.parent.loc.end)
            node.source_range.begin.join(end_loc.begin)
          else
            deletion_range(branch_range(node))
          end

  corrector.remove(range)
end


  








  

    #require_other_branches_correction?(node)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/empty_conditional_body.rb', line 137



def require_other_branches_correction?(node)
  return false unless node.if_type? && node.else?
  return false if !empty_if_branch?(node) && node.elsif?

  !empty_elsif_branch?(node)
end