Class: RuboCop::Cop::Style::IfUnlessModifier

Inherits:
Cop
  • Object
show all
Includes:
RuboCop::Cop::StatementModifier
Defined in:
lib/rubocop/cop/style/if_unless_modifier.rb

Overview

Checks for if and unless statements that would fit on one line if written as a modifier if/unless. The maximum line length is configurable.

Constant Summary collapse

ASSIGNMENT_TYPES = 
[:lvasgn, :casgn, :cvasgn,
:gvasgn, :ivasgn, :masgn].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 RuboCop::Cop::StatementModifier

#body_has_comment?, #body_length, #comment_lines, #end_keyword_has_comment?, #fit_within_line_as_modifier_form?, #length, #max_line_length

Methods included from IfNode

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

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?, 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, ternary_op?, to_string_literal, to_symbol_literal, within_node?

Methods included from PathUtil

absolute?, hidden?, issue_deprecation_warning, 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/if_unless_modifier.rb', line 52

def autocorrect(node)
  cond, body, _else = if_node_parts(node)

  oneline =
    "#{body.source} #{node.loc.keyword.source} " + cond.source
  first_line_comment = processed_source.comments.find do |c|
    c.loc.line == node.loc.line
  end
  if first_line_comment
    oneline << ' ' << first_line_comment.loc.expression.source
  end
  oneline = "(#{oneline})" if parenthesize?(node)

  ->(corrector) { corrector.replace(node.source_range, oneline) }
end

#message(keyword) ⇒ Object 



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# File 'lib/rubocop/cop/style/if_unless_modifier.rb', line 16

def message(keyword)
  "Favor modifier `#{keyword}` usage when having a single-line body." \
  ' Another good alternative is the usage of control flow `&&`/`||`.'
end

#method_uses_parens?(node, limit) ⇒ Boolean

Returns:

  • (Boolean) 


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

def method_uses_parens?(node, limit)
  source = node.source_range.source_line[0...limit.loc.column]
  source =~ /\s*\(\s*$/
end

#on_if(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/if_unless_modifier.rb', line 21

def on_if(node)
  # discard ternary ops, if/else and modifier if/unless nodes
  return if ternary_op?(node)
  return if modifier_if?(node)
  return if elsif?(node)
  return if if_else?(node)
  return if node.chained?
  return unless fit_within_line_as_modifier_form?(node)
  add_offense(node, :keyword, message(node.loc.keyword.source))
end

#parenthesize?(node) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rubocop/cop/style/if_unless_modifier.rb', line 32

def parenthesize?(node)
  # Parenthesize corrected expression if changing to modifier-if form
  # would change the meaning of the parent expression
  # (due to the low operator precedence of modifier-if)
  return false if node.parent.nil?
  return true if ASSIGNMENT_TYPES.include?(node.parent.type)

  if node.parent.send_type?
    _receiver, _name, *args = *node.parent
    return !method_uses_parens?(node.parent, args.first)
  end

  false
end