@nozbe/watermelondb/src/utils/common/ensureSync/index.js

Build powerful React Native and React web apps that scale from hundreds to tens of thousands of records and remain fast

// @flow

import invariant from '../invariant'

// Throws if passed value is a Promise
// Otherwise, returns the passed value as-is.
//
// Use to ensure API users aren't passing async functions

export default function ensureSync<T>(value: T): T {
  invariant(
    !(value instanceof Promise),
    'Unexpected Promise. Passed function should be synchronous.',
  )

  return value
}