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Class: RuboCop::Cop::Style::ParenthesesAroundCondition

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/parentheses_around_condition.rb

Overview

Checks for the presence of superfluous parentheses around the condition of if/unless/while/until.

AllowSafeAssignment option for safe assignment. By safe assignment we mean putting parentheses around an assignment to indicate "I know I’m using an assignment as a condition. It’s not a mistake."

Examples:

# bad
x += 1 while (x < 10)
foo unless (bar || baz)

if (x > 10)
elsif (x < 3)
end

# good
x += 1 while x < 10
foo unless bar || baz

if x > 10
elsif x < 3
end

AllowSafeAssignment: true (default)

# good
foo unless (bar = baz)

AllowSafeAssignment: false

# bad
foo unless (bar = baz)

AllowInMultilineConditions: false (default)

# bad
if (x > 10 &&
   y > 10)
end

# good
 if x > 10 &&
    y > 10
 end

AllowInMultilineConditions: true

# good
if (x > 10 &&
   y > 10)
end

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

::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::Parentheses - Included

::RuboCop::Cop::SafeAssignment - 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

#allow_multiline_conditions?Boolean (readonly, private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/parentheses_around_condition.rb', line 130

def allow_multiline_conditions?
  cop_config['AllowInMultilineConditions']
end

Instance Method Details

#control_op_condition(node) (private)

[ GitHub ]

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

def_node_matcher :control_op_condition, <<~PATTERN
  (begin $_ $...)
PATTERN

#message(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/parentheses_around_condition.rb', line 118

def message(node)
  kw = node.parent.keyword
  article = kw == 'while' ? 'a' : 'an'
  "Don't use parentheses around the condition of #{article} `#{kw}`."
end

#modifier_op?(node) ⇒ Boolean (private)

[ GitHub ]

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

def modifier_op?(node)
  return false if node.if_type? && node.ternary?
  return true if node.rescue_type?

  node.basic_conditional? && node.modifier_form?
end

#on_if(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/parentheses_around_condition.rb', line 62

def on_if(node)
  return if node.ternary?

  process_control_op(node)
end

#on_until(node)

Alias for #on_while.

[ GitHub ]

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

alias on_until on_while

#on_while(node) Also known as: #on_until

[ GitHub ]

  
# File 'lib/rubocop/cop/style/parentheses_around_condition.rb', line 68

def on_while(node)
  process_control_op(node)
end

#parens_allowed?(node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/parentheses_around_condition.rb', line 124

def parens_allowed?(node)
  parens_required?(node) ||
    (safe_assignment?(node) && safe_assignment_allowed?) ||
    (node.multiline? && allow_multiline_conditions?)
end

#process_control_op(node) (private)

[ GitHub ]

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

def process_control_op(node)
  cond = node.condition

  control_op_condition(cond) do |first_child, rest_children|
    return if require_parentheses?(node, first_child)
    return if semicolon_separated_expressions?(first_child, rest_children)
    return if modifier_op?(first_child)
    return if parens_allowed?(cond)

    message = message(cond)
    add_offense(cond, message: message) do |corrector|
      ParenthesesCorrector.correct(corrector, cond)
    end
  end
end

#require_parentheses?(node, condition_body) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/parentheses_around_condition.rb', line 96

def require_parentheses?(node, condition_body)
  return false if !node.while_type? && !node.until_type?
  return false if !condition_body.block_type? && !condition_body.numblock_type?

  condition_body.send_node.block_literal? && condition_body.keywords?
end

#semicolon_separated_expressions?(first_exp, rest_exps) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/parentheses_around_condition.rb', line 103

def semicolon_separated_expressions?(first_exp, rest_exps)
  return false unless (second_exp = rest_exps.first)

  range = range_between(first_exp.source_range.end_pos, second_exp.source_range.begin_pos)

  range.source.include?(';')
end