class RuboCop::Cop::Lint::SelfAssignment


= hash[foo]
# good (method calls possibly can return different results)
obj.attr = obj.attr2<br>hash = hash[‘bar’]
Foo = Bar
foo, bar = bar, foo
foo = bar
# good
obj.attr = obj.attr<br>hash = hash[‘foo’]
Foo = Foo
foo, bar = foo, bar
foo = foo
# bad
@example
Checks for self-assignments.

def handle_attribute_assignment(node) 

def handle_attribute_assignment(node)
  first_argument = node.first_argument
  return unless first_argument.respond_to?(:arguments) && first_argument.arguments.empty?
  if first_argument.call_type? &&
     node.receiver == first_argument.receiver &&
     first_argument.method_name.to_s == node.method_name.to_s.delete_suffix('=')
    add_offense(node)
  end
end

def handle_key_assignment(node) 

def handle_key_assignment(node)
  value_node = node.arguments[1]
  if value_node.send_type? && value_node.method?(:[]) &&
     node.receiver == value_node.receiver &&
     !node.first_argument.call_type? &&
     node.first_argument == value_node.first_argument
    add_offense(node)
  end
end

def multiple_self_assignment?(node) 

def multiple_self_assignment?(node)
  lhs = node.lhs
  rhs = node.rhs
  return false unless rhs.array_type?
  return false unless lhs.children.size == rhs.children.size
  lhs.children.zip(rhs.children).all? do |lhs_item, rhs_item|
    rhs_matches_lhs?(rhs_item, lhs_item)
  end
end

def on_casgn(node) 

def on_casgn(node)
  return unless node.rhs&.const_type?
  add_offense(node) if node.namespace == node.rhs.namespace &&
                       node.short_name == node.rhs.short_name
end

def on_lvasgn(node) 

def on_lvasgn(node)
  return unless node.rhs
  rhs_type = ASSIGNMENT_TYPE_TO_RHS_TYPE[node.type]
  add_offense(node) if node.rhs.type == rhs_type && node.rhs.source == node.lhs.to_s
end

def on_masgn(node) 

def on_masgn(node)
  add_offense(node) if multiple_self_assignment?(node)
end

def on_or_asgn(node) 

def on_or_asgn(node)
  add_offense(node) if rhs_matches_lhs?(node.rhs, node.lhs)
end

def on_send(node) 

def on_send(node)
  if node.method?(:[]=)
    handle_key_assignment(node) if node.arguments.size == 2
  elsif node.assignment_method?
    handle_attribute_assignment(node) if node.arguments.size == 1
  end
end

def rhs_matches_lhs?(rhs, lhs) 

def rhs_matches_lhs?(rhs, lhs)
  rhs.type == ASSIGNMENT_TYPE_TO_RHS_TYPE[lhs.type] &&
    rhs.children.first == lhs.children.first
end