Class: RuboCop::Cop::Style::NestedModifier

Inherits:
Cop
  • Object
show all
Includes:
IfNode
Defined in:
lib/rubocop/cop/style/nested_modifier.rb

Overview

This cop checks for nested use of if, unless, while and until in their modifier form.

Examples:


# bad
something if a if b

# good
something if b && a

Constant Summary collapse

MSG = 
'Avoid using nested modifiers.'.freeze

Constants included from Util

Util::ASGN_NODES, Util::BYTE_ORDER_MARK, Util::EQUALS_ASGN_NODES, Util::LITERAL_REGEX, Util::OPERATOR_METHODS, Util::SHORTHAND_ASGN_NODES, Util::STRING_ESCAPES, Util::STRING_ESCAPE_REGEX

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

Methods included from IfNode

#elsif?, #if_else?, #if_node_parts, #modifier_if?, #ternary?

Methods inherited from Cop

#add_offense, all, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, cop_name, #cop_name, cop_type, #correct, #debug?, #details, #display_cop_names?, #display_style_guide?, #excluded_file?, #extra_details?, inherited, #initialize, #join_force?, lint?, match?, #message, non_rails, #parse, qualified_cop_name, #reference_url, #relevant_file?, #style_guide_url, #target_ruby_version

Methods included from Sexp

#s

Methods included from NodePattern::Macros

#def_node_matcher, #def_node_search, #node_search_body

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #support_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

begins_its_line?, block_length, comment_line?, directions, double_quotes_acceptable?, double_quotes_required?, effective_column, ends_its_line?, first_part_of_call_chain, interpret_string_escapes, line_range, move_pos, numeric_range_size, on_node, operator?, parentheses?, parenthesized_call?, range_with_surrounding_comma, range_with_surrounding_space, source_range, strip_quotes, to_string_literal, to_symbol_literal, within_node?

Methods included from PathUtil

absolute?, match_path?, relative_path

Constructor Details

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

Instance Method Details

#autocorrect(node) ⇒ Object 



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

def autocorrect(node)
  return unless node.if_type?

  ancestor = node.ancestors.first
  return unless ancestor.if_type?

  autocorrect_if_unless(ancestor, node)
end

#autocorrect_if_unless(outer_node, inner_node) ⇒ Object 



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# File 'lib/rubocop/cop/style/nested_modifier.rb', line 66

def autocorrect_if_unless(outer_node, inner_node)
  outer_cond, = *outer_node

  range =
    Parser::Source::Range.new(inner_node.source_range.source_buffer,
                              inner_node.loc.keyword.begin_pos,
                              outer_cond.source_range.end_pos)

  lambda do |corrector|
    corrector.replace(range, new_expression(outer_node, inner_node))
  end
end

#check(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/nested_modifier.rb', line 34

def check(node)
  return if part_of_ignored_node?(node)
  return unless modifier?(node)

  ancestor = node.ancestors.first
  return unless ancestor &&
                [:if, :while, :until].include?(ancestor.type) &&
                modifier?(ancestor)

  add_offense(node, :keyword)
  ignore_node(node)
end

#modifier?(node) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rubocop/cop/style/nested_modifier.rb', line 47

def modifier?(node)
  modifier_if?(node) || modifier_while_or_until?(node)
end

#modifier_while_or_until?(node) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rubocop/cop/style/nested_modifier.rb', line 51

def modifier_while_or_until?(node)
  node.loc.respond_to?(:keyword) &&
    %w(while until).include?(node.loc.keyword.source) &&
    node.loc.respond_to?(:end) && node.loc.end.nil?
end

#new_expression(outer_node, inner_node) ⇒ Object 



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# File 'lib/rubocop/cop/style/nested_modifier.rb', line 79

def new_expression(outer_node, inner_node)
  outer_cond, = *outer_node
  inner_cond, = *inner_node

  outer_keyword = outer_node.loc.keyword.source
  inner_keyword = inner_node.loc.keyword.source

  operator = outer_keyword == 'if'.freeze ? '&&'.freeze : '||'.freeze

  outer_expr = outer_cond.source
  outer_expr = "(#{outer_expr})" if outer_cond.or_type? &&
                                    operator == '&&'.freeze
  inner_expr = inner_cond.source

  inner_expr = "(#{inner_expr})" if requires_parens?(inner_cond)
  inner_expr = "!#{inner_expr}" unless outer_keyword == inner_keyword

  "#{outer_node.loc.keyword.source} " \
  "#{outer_expr} #{operator} #{inner_expr}"
end

#on_if(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/nested_modifier.rb', line 30

def on_if(node)
  check(node)
end

#on_until(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/nested_modifier.rb', line 26

def on_until(node)
  check(node)
end

#on_while(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/nested_modifier.rb', line 22

def on_while(node)
  check(node)
end

#requires_parens?(node) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rubocop/cop/style/nested_modifier.rb', line 100

def requires_parens?(node)
  node.or_type? ||
    !(RuboCop::Node::COMPARISON_OPERATORS & node.children).empty?
end