How do I get the input type for `type`?

export function validateEnv<T extends Record<string, unknown>>(
  def: ?,
) {
  const schema = type(def)
  const envVars = Object.fromEntries(
    Object.keys(schemaDefinition).map((key) => [key, process.env[key]]),
  )
  const result = schema(envVars)

  if (result instanceof type.errors) {
    throw new TypeError(result.summary)
  }

  return result
}

validateEnv({
  DATABASE_URL: 'string'
})

export function validateEnv<T extends Record<string, unknown>>(
  def: ?,
) {
  const schema = type(def)
  const envVars = Object.fromEntries(
    Object.keys(schemaDefinition).map((key) => [key, process.env[key]]),
  )
  const result = schema(envVars)

  if (result instanceof type.errors) {
    throw new TypeError(result.summary)
  }

  return result
}

validateEnv({
  DATABASE_URL: 'string'
})