Class: RuboCop::Cop::VariableForce::Variable Private

Inherits:
Object
  • Object
show all
Extended by:
Macros
Defined in:
lib/rubocop/cop/variable_force/variable.rb

Overview

This class is part of a private API. You should avoid using this class if possible, as it may be removed or be changed in the future.

A Variable represents existence of a local variable. This holds a variable declaration node and some states of the variable.

Constant Summary collapse

VARIABLE_DECLARATION_TYPES =

This constant is part of a private API. You should avoid using this constant if possible, as it may be removed or be changed in the future. 

(VARIABLE_ASSIGNMENT_TYPES + ARGUMENT_DECLARATION_TYPES).freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, declaration_node, scope) ⇒ Variable

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a new instance of Variable.



17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
 
# File 'lib/rubocop/cop/variable_force/variable.rb', line 17

def initialize(name, declaration_node, scope)
  unless VARIABLE_DECLARATION_TYPES.include?(declaration_node.type)
    raise ArgumentError,
          "Node type must be any of #{VARIABLE_DECLARATION_TYPES}, " \
          "passed #{declaration_node.type}"
  end

  @name = name.to_sym
  @declaration_node = declaration_node
  @scope = scope

  @assignments = []
  @references = []
  @captured_by_block = false
end

Instance Attribute Details

#assignments ⇒ Object (readonly)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



13
14
15
 
# File 'lib/rubocop/cop/variable_force/variable.rb', line 13

def assignments
  @assignments
end

#captured_by_block ⇒ Object (readonly) Also known as: captured_by_block?

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



13
14
15
 
# File 'lib/rubocop/cop/variable_force/variable.rb', line 13

def captured_by_block
  @captured_by_block
end

#declaration_node ⇒ Object (readonly)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



13
14
15
 
# File 'lib/rubocop/cop/variable_force/variable.rb', line 13

def declaration_node
  @declaration_node
end

#name ⇒ Object (readonly)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



13
14
15
 
# File 'lib/rubocop/cop/variable_force/variable.rb', line 13

def name
  @name
end

#references ⇒ Object (readonly)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



13
14
15
 
# File 'lib/rubocop/cop/variable_force/variable.rb', line 13

def references
  @references
end

#scope ⇒ Object (readonly)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



13
14
15
 
# File 'lib/rubocop/cop/variable_force/variable.rb', line 13

def scope
  @scope
end

Instance Method Details

#argument? ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



110
111
112
 
# File 'lib/rubocop/cop/variable_force/variable.rb', line 110

def argument?
  ARGUMENT_DECLARATION_TYPES.include?(@declaration_node.type)
end

#assign(node) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



33
34
35
36
37
38
39
 
# File 'lib/rubocop/cop/variable_force/variable.rb', line 33

def assign(node)
  assignment = Assignment.new(node, self)

  mark_last_as_reassigned!(assignment)

  @assignments << assignment
end

#block_argument? ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



118
119
120
 
# File 'lib/rubocop/cop/variable_force/variable.rb', line 118

def block_argument?
  argument? && @scope.node.block_type?
end

#candidate_condition?(node) ⇒ Object 



49
 
# File 'lib/rubocop/cop/variable_force/variable.rb', line 49

def_node_matcher :candidate_condition?, '[{if case case_match when}]'

#capture_with_block! ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



90
91
92
 
# File 'lib/rubocop/cop/variable_force/variable.rb', line 90

def capture_with_block!
  @captured_by_block = true
end

#explicit_block_local_variable? ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



126
127
128
 
# File 'lib/rubocop/cop/variable_force/variable.rb', line 126

def explicit_block_local_variable?
  @declaration_node.shadowarg_type?
end

#in_modifier_conditional?(assignment) ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

rubocop:enable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity



82
83
84
85
86
87
88
 
# File 'lib/rubocop/cop/variable_force/variable.rb', line 82

def in_modifier_conditional?(assignment)
  parent = assignment.node.parent
  parent = parent.parent if parent&.begin_type?
  return false if parent.nil?

  parent.type?(:if, :while, :until) && parent.modifier_form?
end

#keyword_argument? ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



122
123
124
 
# File 'lib/rubocop/cop/variable_force/variable.rb', line 122

def keyword_argument?
  %i[kwarg kwoptarg].include?(@declaration_node.type)
end

#mark_last_as_reassigned!(assignment) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



41
42
43
44
45
46
 
# File 'lib/rubocop/cop/variable_force/variable.rb', line 41

def mark_last_as_reassigned!(assignment)
  return if captured_by_block?
  return if candidate_condition?(assignment.node.parent)

  @assignments.last&.reassigned!
end

#method_argument? ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



114
115
116
 
# File 'lib/rubocop/cop/variable_force/variable.rb', line 114

def method_argument?
  argument? && %i[def defs].include?(@scope.node.type)
end

#reference!(node) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

rubocop:disable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity



56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
 
# File 'lib/rubocop/cop/variable_force/variable.rb', line 56

def reference!(node)
  reference = Reference.new(node, @scope)
  @references << reference
  consumed_branches = nil

  @assignments.reverse_each do |assignment|
    next if consumed_branches&.include?(assignment.branch)

    assignment.reference!(node) unless assignment.run_exclusively_with?(reference)

    # Modifier if/unless conditions are special. Assignments made in
    # them do not put the assigned variable in scope to the left of the
    # if/unless keyword. A preceding assignment is needed to put the
    # variable in scope. For this reason we skip to the next assignment
    # here.
    next if in_modifier_conditional?(assignment)

    break if !assignment.branch || assignment.branch == reference.branch

    unless assignment.branch.may_run_incompletely?
      (consumed_branches ||= Set.new) << assignment.branch
    end
  end
end

#referenced? ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



51
52
53
 
# File 'lib/rubocop/cop/variable_force/variable.rb', line 51

def referenced?
  !@references.empty?
end

#should_be_unused? ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



106
107
108
 
# File 'lib/rubocop/cop/variable_force/variable.rb', line 106

def should_be_unused?
  name.to_s.start_with?('_')
end

#used? ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

This is a convenient way to check whether the variable is used in its entire variable lifetime. For more precise usage check, refer Assignment#used?.

Once the variable is captured by a block, we have no idea when, where, and how many times the block would be invoked. This means we cannot track the usage of the variable. So we consider it’s used to suppress false positive offenses.



102
103
104
 
# File 'lib/rubocop/cop/variable_force/variable.rb', line 102

def used?
  @captured_by_block || referenced?
end