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Class: RuboCop::Cop::Style::UnlessLogicalOperators

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

Overview

Checks for the use of logical operators in an unless condition. It discourages such code, as the condition becomes more difficult to read and understand.

This cop supports two styles:

  • forbid_mixed_logical_operators (default)

  • forbid_logical_operators

forbid_mixed_logical_operators style forbids the use of more than one type of logical operators. This makes the unless condition easier to read because either all conditions need to be met or any condition need to be met in order for the expression to be truthy or falsey.

forbid_logical_operators style forbids any use of logical operator. This makes it even more easy to read the unless condition as there is only one condition in the expression.

Examples:

EnforcedStyle: forbid_mixed_logical_operators (default)

# bad
return unless a || b && c
return unless a && b || c
return unless a && b and c
return unless a || b or c
return unless a && b or c
return unless a || b and c

# good
return unless a && b && c
return unless a || b || c
return unless a and b and c
return unless a or b or c
return unless a?

EnforcedStyle: forbid_logical_operators

# bad
return unless a || b
return unless a && b
return unless a or b
return unless a and b

# good
return unless a
return unless a?

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

::RuboCop::Cop::ConfigurableEnforcedStyle - Included

SYMBOL_TO_STRING_CACHE

Class Attribute Summary

::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::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 Method Details

#and_with_or?(node)

[ GitHub ]

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

def_node_matcher :and_with_or?, <<~PATTERN
  (if (and <`or ...> ) ...)
PATTERN

#logical_operator?(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/unless_logical_operators.rb', line 67

def_node_matcher :logical_operator?, <<~PATTERN
  (if ({and or} ... ) ...)
PATTERN

#mixed_logical_operator?(node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/unless_logical_operators.rb', line 83

def mixed_logical_operator?(node)
  or_with_and?(node) ||
    and_with_or?(node) ||
    mixed_precedence_and?(node) ||
    mixed_precedence_or?(node)
end

#mixed_precedence_and?(node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/unless_logical_operators.rb', line 90

def mixed_precedence_and?(node)
  and_sources = node.condition.each_descendant(:and).map(&:operator)
  and_sources << node.condition.operator if node.condition.and_type?

  !(and_sources.all?('&&') || and_sources.all?('and'))
end

#mixed_precedence_or?(node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/unless_logical_operators.rb', line 97

def mixed_precedence_or?(node)
  or_sources = node.condition.each_descendant(:or).map(&:operator)
  or_sources << node.condition.operator if node.condition.or_type?

  !(or_sources.all?('||') || or_sources.all?('or'))
end

#on_if(node)

[ GitHub ]

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

def on_if(node)
  return unless node.unless?

  if style == :forbid_mixed_logical_operators && mixed_logical_operator?(node)
    add_offense(node, message: FORBID_MIXED_LOGICAL_OPERATORS)
  elsif style == :forbid_logical_operators && logical_operator?(node)
    add_offense(node, message: FORBID_LOGICAL_OPERATORS)
  end
end

#or_with_and?(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/unless_logical_operators.rb', line 57

def_node_matcher :or_with_and?, <<~PATTERN
  (if (or <`and ...> ) ...)
PATTERN