message: BigInt not serializing issue
diff: @@ -7,7 +7,7 @@ export default function (name = 'BigInt') {
  name,
  description:
  'The `BigInt` scalar type represents non-fractional signed whole numeric values.',
  - serialize: BigInt,
  + serialize: val => val.toString(),
  parseValue: BigInt,
  parseLiteral(ast) {
  if (ast.kind === Kind.INT || ast.kind === Kind.FLOAT || ast.kind === Kind.STRING) {
  