Class: RuboCop::Cop::Style::ConditionalAssignment

Inherits:

Base

• Object
• Base
• RuboCop::Cop::Style::ConditionalAssignment

Extended by:

AutoCorrector

Includes:

ConfigurableEnforcedStyle, ConditionalAssignmentHelper

Defined in:

lib/rubocop/cop/style/conditional_assignment.rb

Overview

Check for ‘if` and `case` statements where each branch is used for both the assignment and comparison of the same variable when using the return of the condition can be used instead.

Examples:

EnforcedStyle: assign_to_condition (default)

# bad
if foo
  bar = 1
else
  bar = 2
end

case foo
when 'a'
  bar += 1
else
  bar += 2
end

if foo
  some_method
  bar = 1
else
  some_other_method
  bar = 2
end

# good
bar = if foo
        1
      else
        2
      end

bar += case foo
       when 'a'
         1
       else
         2
       end

bar << if foo
         some_method
         1
       else
         some_other_method
         2
       end

EnforcedStyle: assign_inside_condition

# bad
bar = if foo
        1
      else
        2
      end

bar += case foo
       when 'a'
         1
       else
         2
       end

bar << if foo
         some_method
         1
       else
         some_other_method
         2
       end

# good
if foo
  bar = 1
else
  bar = 2
end

case foo
when 'a'
  bar += 1
else
  bar += 2
end

if foo
  some_method
  bar = 1
else
  some_other_method
  bar = 2
end

Constant Summary

MSG =

'Use the return of the conditional for variable assignment and comparison.'

ASSIGN_TO_CONDITION_MSG =

'Assign variables inside of conditionals.'

VARIABLE_ASSIGNMENT_TYPES =

%i[casgn cvasgn gvasgn ivasgn lvasgn].freeze

ASSIGNMENT_TYPES =

VARIABLE_ASSIGNMENT_TYPES + %i[and_asgn or_asgn op_asgn masgn].freeze

LINE_LENGTH =

'Layout/LineLength'

ENABLED =

'Enabled'

MAX =

'Max'

SINGLE_LINE_CONDITIONS_ONLY =

'SingleLineConditionsOnly'

Constants included from ConditionalAssignmentHelper

RuboCop::Cop::Style::ConditionalAssignmentHelper::ALIGN_WITH, RuboCop::Cop::Style::ConditionalAssignmentHelper::END_ALIGNMENT, RuboCop::Cop::Style::ConditionalAssignmentHelper::EQUAL, RuboCop::Cop::Style::ConditionalAssignmentHelper::KEYWORD

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary

• #assignment_type?(node) ⇒ Object

  The shovel operator ‘<<` does not have its own type.

• #on_case(node) ⇒ Object
• #on_case_match(node) ⇒ Object
• #on_if(node) ⇒ Object
• #on_send(node) ⇒ Object

Methods included from AutoCorrector

support_autocorrect?

Methods included from ConfigurableEnforcedStyle

#alternative_style, #alternative_styles, #ambiguous_style_detected, #correct_style_detected, #detected_style, #detected_style=, #no_acceptable_style!, #no_acceptable_style?, #opposite_style_detected, #style, #style_configured?, #style_detected, #style_parameter_name, #supported_styles, #unexpected_style_detected

Methods included from ConditionalAssignmentHelper

#end_with_eq?, #expand_elses, #expand_when_branches, #indent, #lhs, #tail

Methods inherited from Base

#active_support_extensions_enabled?, #add_global_offense, #add_offense, #always_autocorrect?, autocorrect_incompatible_with, badge, #begin_investigation, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #contextual_autocorrect?, #cop_config, cop_name, #cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, #inspect, joining_forces, lint?, match?, #message, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #parse, #parser_engine, #ready, #relevant_file?, requires_gem, #string_literals_frozen_by_default?, support_autocorrect?, support_multiple_source?, #target_rails_version, #target_ruby_version

Methods included from ExcludeLimit

#exclude_limit

Methods included from AutocorrectLogic

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

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

silence_warnings

Constructor Details

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

Instance Method Details

#assignment_type?(node) ⇒ Object

The shovel operator ‘<<` does not have its own type. It is a `send` type.

# File 'lib/rubocop/cop/style/conditional_assignment.rb', line 224

def_node_matcher :assignment_type?, <<~PATTERN
  {
    #{ASSIGNMENT_TYPES.join(' ')}
    (send _recv {:[]= :<< :=~ :!~ :<=> #end_with_eq? :< :>} ...)
  }
PATTERN

#on_case(node) ⇒ Object

# File 'lib/rubocop/cop/style/conditional_assignment.rb', line 260

def on_case(node)
  return unless style == :assign_to_condition
  return unless node.else_branch

  when_branches = expand_when_branches(node.when_branches)
  branches = [*when_branches, node.else_branch]

  check_node(node, branches)
end

#on_case_match(node) ⇒ Object

# File 'lib/rubocop/cop/style/conditional_assignment.rb', line 270

def on_case_match(node)
  return unless style == :assign_to_condition
  return unless node.else_branch

  in_pattern_branches = expand_when_branches(node.in_pattern_branches)
  branches = [*in_pattern_branches, node.else_branch]

  check_node(node, branches)
end

#on_if(node) ⇒ Object

# File 'lib/rubocop/cop/style/conditional_assignment.rb', line 246

def on_if(node)
  return unless style == :assign_to_condition
  return if node.elsif?

  else_branch = node.else_branch
  elsif_branches, else_branch = expand_elses(else_branch)

  return unless else_branch

  branches = [node.if_branch, *elsif_branches, else_branch]

  check_node(node, branches)
end

#on_send(node) ⇒ Object

# File 'lib/rubocop/cop/style/conditional_assignment.rb', line 240

def on_send(node)
  return unless assignment_type?(node)

  check_assignment_to_condition(node)
end