class RuboCop::Cop::Lint::SelfAssignment

def multiple_self_assignment?(node)
  lhs, rhs = *node
  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)
  lhs_scope, lhs_name, rhs = *node
  return unless rhs&.const_type?
  rhs_scope, rhs_name = *rhs
  add_offense(node) if lhs_scope == rhs_scope && lhs_name == rhs_name
end

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

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

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

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