class RuboCop::Cop::Lint::DisjunctiveAssignmentInConstructor

end
@x = 1
def initialize
# good
end
@x ||= 1
def initialize
# bad
@example
the value for ‘@config`.
Without the disjunctive assignment, `Derived` will be unable to override
—-
end
end
super
@config = ’derived’
def initialize
class Derived < Base
end
end
@config ||= ‘base’
def initialize
class Base
—-
[source,ruby]

method is redefined in a subclass that calls super. For example:
This cop is unsafe because it can register a false positive when a
@safety
disjunction is unnecessary. A plain assignment has the same effect.
In ruby, an instance variable is nil until a value is assigned, so the
instance variables.
So far, this cop is only concerned with disjunctive assignment of
be plain assignments.
Checks constructors for disjunctive assignments (‘||=`) that should

def check(node)

Parameters:
  • node (DefNode) -- a constructor definition 
def check(node)
  return unless node.method?(:initialize)
  check_body(node.body)
end

def check_body(body) 

def check_body(body)
  return if body.nil?
  case body.type
  when :begin
    check_body_lines(body.child_nodes)
  else
    check_body_lines([body])
  end
end

def check_body_lines(lines)

Parameters:
  • lines (Array) -- the logical lines of the constructor 
def check_body_lines(lines)
  lines.each do |line|
    case line.type
    when :or_asgn
      check_disjunctive_assignment(line)
    else
      # Once we encounter something other than a disjunctive
      # assignment, we cease our investigation, because we can't be
      # certain that any future disjunctive assignments are offensive.
      # You're off the case, detective!
      break
    end
  end
end

def check_disjunctive_assignment(node)

Parameters:
  • node (Node) -- a disjunctive assignment 
def check_disjunctive_assignment(node)
  lhs = node.child_nodes.first
  return unless lhs.ivasgn_type?
  add_offense(node.loc.operator) do |corrector|
    corrector.replace(node.loc.operator, '=')
  end
end

def on_def(node) 

def on_def(node)
  check(node)
end