wynn/ts/scratch/test.ts

import { ArkErrors, type } from 'arktype'

const tupleType = type(['number', 'string'])
const tupleArrayType = tupleType.array()
const unionType = tupleType.or(tupleArrayType)

// good
tupleType.assert([1, '2'])
// good
tupleArrayType.assert([[1, '2']])

// no good!
const resp = unionType([[1, '2']])
if (resp instanceof ArkErrors) {
  const err = resp[0]
  console.log(err.data)
  console.log(err.problem)
  console.log(err.message)
  console.log(err.path)
}