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Class: RuboCop::Cop::Style::SoleNestedConditional

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/sole_nested_conditional.rb

Overview

If the branch of a conditional consists solely of a conditional node, its conditions can be combined with the conditions of the outer branch. This helps to keep the nesting level from getting too deep.

Examples:

# bad
if condition_a
  if condition_b
    do_something
  end
end

# bad
if condition_b
  do_something
end if condition_a

# good
if condition_a && condition_b
  do_something
end

AllowModifier: false (default)

# bad
if condition_a
  do_something if condition_b
end

# bad
if condition_b
  do_something
end if condition_a

AllowModifier: true

# good
if condition_a
  do_something if condition_b
end

# good
if condition_b
  do_something
end if condition_a

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.

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::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::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

Class Method Details

.autocorrect_incompatible_with

[ GitHub ]

  
# File 'lib/rubocop/cop/style/sole_nested_conditional.rb', line 55

def self.autocorrect_incompatible_with
  [Style::NegatedIf, Style::NegatedUnless]
end

Instance Attribute Details

#allow_modifier?Boolean (readonly, private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/sole_nested_conditional.rb', line 261

def allow_modifier?
  cop_config['AllowModifier']
end

Instance Method Details

#arguments_range(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/sole_nested_conditional.rb', line 233

def arguments_range(node)
  range_between(
    node.first_argument.source_range.begin_pos, node.last_argument.source_range.end_pos
  )
end

#assigned_variables(condition) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/sole_nested_conditional.rb', line 81

def assigned_variables(condition)
  assigned_variables = condition.assignment? ? [condition.children.first.to_s] : []

  assigned_variables + condition.descendants.select(&:assignment?).map do |node|
    node.children.first.to_s
  end
end

#autocorrect(corrector, node, if_branch) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/sole_nested_conditional.rb', line 98

def autocorrect(corrector, node, if_branch)
  if node.condition.or_type? || node.condition.assignment?
    corrector.wrap(node.condition, '(', ')')
  end

  if outer_condition_modify_form?(node, if_branch)
    autocorrect_outer_condition_modify_form(corrector, node, if_branch)
  else
    autocorrect_outer_condition_basic(corrector, node, if_branch)
  end
end

#autocorrect_outer_condition_basic(corrector, node, if_branch) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/sole_nested_conditional.rb', line 110

def autocorrect_outer_condition_basic(corrector, node, if_branch)
  correct_from_unless_to_if(corrector, node) if node.unless?

  outer_condition = node.condition
  correct_outer_condition(corrector, outer_condition)

  and_operator = if_branch.unless? ? ' && !' : ' && '
  if if_branch.modifier_form?
    correct_for_guard_condition_style(corrector, outer_condition, if_branch, and_operator)
  else
    correct_for_basic_condition_style(corrector, node, if_branch, and_operator)
    correct_for_comment(corrector, node, if_branch)
  end
end

#autocorrect_outer_condition_modify_form(corrector, node, if_branch) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/sole_nested_conditional.rb', line 125

def autocorrect_outer_condition_modify_form(corrector, node, if_branch)
  correct_from_unless_to_if(corrector, if_branch, is_modify_form: true) if if_branch.unless?
  correct_for_outer_condition_modify_form_style(corrector, node, if_branch)
end

#correct_for_basic_condition_style(corrector, node, if_branch, and_operator) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/sole_nested_conditional.rb', line 145

def correct_for_basic_condition_style(corrector, node, if_branch, and_operator)
  range = range_between(
    node.condition.source_range.end_pos, if_branch.condition.source_range.begin_pos
  )
  corrector.replace(range, and_operator)
  corrector.remove(range_by_whole_lines(node.loc.end, include_final_newline: true))

  wrap_condition(corrector, if_branch.condition)
end

#correct_for_comment(corrector, node, if_branch) (private)

[ GitHub ]

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

def correct_for_comment(corrector, node, if_branch)
  comments = processed_source.ast_with_comments[if_branch].select do |comment|
    comment.loc.line < if_branch.condition.first_line
  end
  comment_text = comments.map(&:text).join("\n") << "\n"

  corrector.insert_before(node.loc.keyword, comment_text) unless comments.empty?
end

#correct_for_guard_condition_style(corrector, outer_condition, if_branch, and_operator) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/sole_nested_conditional.rb', line 136

def correct_for_guard_condition_style(corrector, outer_condition, if_branch, and_operator)
  condition = if_branch.condition
  corrector.insert_after(outer_condition, "#{and_operator}#{replace_condition(condition)}")

  range = range_between(if_branch.loc.keyword.begin_pos, condition.source_range.end_pos)
  corrector.remove(range_with_surrounding_space(range, newlines: false))
  corrector.remove(if_branch.loc.keyword)
end

#correct_for_outer_condition_modify_form_style(corrector, node, if_branch) (private)

[ GitHub ]

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

def correct_for_outer_condition_modify_form_style(corrector, node, if_branch)
  condition = if_branch.condition
  corrector.insert_before(condition,
                          "#{'!' if node.unless?}#{replace_condition(node.condition)} && ")

  corrector.remove(node.condition)
  corrector.remove(range_with_surrounding_space(node.loc.keyword, newlines: false))
  corrector.replace(if_branch.loc.keyword, 'if')
end

#correct_from_unless_to_if(corrector, node, is_modify_form: false) (private)

[ GitHub ]

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

def correct_from_unless_to_if(corrector, node, is_modify_form: false)
  corrector.replace(node.loc.keyword, 'if')

  insert_bang(corrector, node, is_modify_form)
end

#correct_outer_condition(corrector, condition) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/sole_nested_conditional.rb', line 190

def correct_outer_condition(corrector, condition)
  return unless require_parentheses?(condition)

  end_pos = condition.loc.selector.end_pos
  begin_pos = condition.first_argument.source_range.begin_pos
  return if end_pos > begin_pos

  range = range_between(end_pos, begin_pos)
  corrector.remove(range)
  corrector.insert_after(range, '(')
  corrector.insert_after(condition.last_argument, ')')
end

#insert_bang(corrector, node, is_modify_form) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/sole_nested_conditional.rb', line 203

def insert_bang(corrector, node, is_modify_form)
  condition = node.condition

  if (condition.send_type? && condition.comparison_method? && !condition.parenthesized?) ||
     (is_modify_form && wrap_condition?(condition))
    corrector.wrap(node.condition, '!(', ')')
  elsif condition.and_type?
    insert_bang_for_and(corrector, node)
  else
    corrector.insert_before(condition, '!')
  end
end

#insert_bang_for_and(corrector, node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/sole_nested_conditional.rb', line 216

def insert_bang_for_and(corrector, node)
  lhs, rhs = *node

  if lhs.and_type?
    insert_bang_for_and(corrector, lhs)
    corrector.insert_before(rhs, '!') if rhs
  else
    corrector.insert_before(lhs, '!')
    corrector.insert_before(rhs, '!')
  end
end

#offending_branch?(node, branch) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/sole_nested_conditional.rb', line 89

def offending_branch?(node, branch)
  return false unless branch

  branch.if_type? &&
    !branch.else? &&
    !branch.ternary? &&
    !((node.modifier_form? || branch.modifier_form?) && allow_modifier?)
end

#on_if(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/sole_nested_conditional.rb', line 59

def on_if(node)
  return if node.ternary? || node.else? || node.elsif?

  if_branch = node.if_branch
  return if use_variable_assignment_in_condition?(node.condition, if_branch)
  return unless offending_branch?(node, if_branch)

  message = format(MSG, conditional_type: node.keyword)
  add_offense(if_branch.loc.keyword, message: message) do |corrector|
    autocorrect(corrector, node, if_branch)
  end
end

#outer_condition_modify_form?(node, if_branch) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/sole_nested_conditional.rb', line 265

def outer_condition_modify_form?(node, if_branch)
  node.condition.source_range.begin_pos > if_branch.condition.source_range.begin_pos
end

#parenthesized_method_arguments(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/sole_nested_conditional.rb', line 254

def parenthesized_method_arguments(node)
  method_call = node.source_range.begin.join(node.loc.selector.end).source
  arguments = node.first_argument.source_range.begin.join(node.source_range.end).source

  "#{method_call}(#{arguments})"
end

#replace_condition(condition) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/sole_nested_conditional.rb', line 244

def replace_condition(condition)
  return condition.source unless wrap_condition?(condition)

  if condition.call_type?
    parenthesized_method_arguments(condition)
  else
    "(#{condition.source})"
  end
end

#require_parentheses?(condition) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/sole_nested_conditional.rb', line 228

def require_parentheses?(condition)
  condition.call_type? && !condition.arguments.empty? && !condition.parenthesized? &&
    !condition.comparison_method?
end

#use_variable_assignment_in_condition?(condition, if_branch) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/sole_nested_conditional.rb', line 74

def use_variable_assignment_in_condition?(condition, if_branch)
  assigned_variables = assigned_variables(condition)

  assigned_variables && if_branch&.if_type? &&
    assigned_variables.include?(if_branch.condition.source)
end

#wrap_condition(corrector, condition) (private)

[ GitHub ]

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

def wrap_condition(corrector, condition)
  # Handle `send` and `block` nodes that need to be wrapped in parens
  # FIXME: autocorrection prevents syntax errors by wrapping the entire node in parens,
  #        but wrapping the argument list would be a more ergonomic correction.
  node_to_check = condition&.block_type? ? condition.send_node : condition
  return unless wrap_condition?(node_to_check)

  if condition.call_type?
    source = parenthesized_method_arguments(condition)

    corrector.replace(condition, source)
  else
    corrector.wrap(condition, '(', ')')
  end
end

#wrap_condition?(node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/sole_nested_conditional.rb', line 239

def wrap_condition?(node)
  node.and_type? || node.or_type? ||
    (node.call_type? && node.arguments.any? && !node.parenthesized?)
end