require("espree").parse('(a = 1) = 2', {sourceType: 'module', ecmaVersion: 2019}).body[0].expression
Node {
  type: 'AssignmentExpression',
  start: 0,
  end: 11,
  operator: '=',
  left: Node {
    type: 'AssignmentPattern',
    start: 1,
    end: 6,
    left: Node { type: 'Identifier', start: 1, end: 2, name: 'a' },
    right: Node { type: 'Literal', start: 5, end: 6, value: 1, raw: '1' }
  },
  right: Node { type: 'Literal', start: 10, end: 11, value: 2, raw: '2' }
}