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30-seconds-of-code/snippets/promisify.md
2017-12-13 10:33:39 +00:00

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### Promisify
Creates a promisified version of the given callback-style function. In Node 8+, you
can use [`util.promisify`](https://nodejs.org/api/util.html#util_util_promisify_original)
```js
const promisify = func =>
(...args) =>
new Promise((resolve, reject) =>
func(...args, (err, result) =>
err
? reject(err)
: resolve(result))
)
// const stat = promisify(fs.stat)
// stat('foo.txt') -> Promise resolves if `foo.txt` exists, otherwise rejects
```