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

Inherits:
Cop
  • Object
show all
Includes:
IfNode, 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

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, #length_in_modifier_form, #max_line_length

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?, #highlights, inherited, #initialize, #join_force?, lint?, match?, #messages, 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?, escape_string, first_part_of_call_chain, interpret_string_escapes, line_range, move_pos, needs_escaping?, 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 



54
55
56
 
# File 'lib/rubocop/cop/style/if_unless_modifier.rb', line 54

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

#message(keyword) ⇒ Object 



17
18
19
20
 
# File 'lib/rubocop/cop/style/if_unless_modifier.rb', line 17

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) 


49
50
51
52
 
# File 'lib/rubocop/cop/style/if_unless_modifier.rb', line 49

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

#on_if(node) ⇒ Object 



22
23
24
25
26
27
28
29
30
31
32
 
# File 'lib/rubocop/cop/style/if_unless_modifier.rb', line 22

def on_if(node)
  # discard ternary ops, if/else and modifier if/unless nodes
  return if ternary?(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)
  return if nested_conditional?(node)
  add_offense(node, :keyword, message(node.loc.keyword.source))
end

#parenthesize?(node) ⇒ Boolean

Returns:

  • (Boolean) 


34
35
36
37
38
39
40
41
42
43
44
45
46
47
 
# File 'lib/rubocop/cop/style/if_unless_modifier.rb', line 34

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