Jaco Greeff
d4491aeb7f
* Small cleanups, u8aConcat oprimizations * Cleanup * Pre-allocate arrays * Don't recreate PREFIX
34 lines
1.2 KiB
TypeScript
34 lines
1.2 KiB
TypeScript
// Copyright 2017-2020 @polkadot/util authors & contributors
|
|
// This software may be modified and distributed under the terms
|
|
// of the Apache-2.0 license. See the LICENSE file for details.
|
|
|
|
/**
|
|
* @name promisify
|
|
* @summary Wraps an async callback into a `Promise`
|
|
* @description
|
|
* Wraps the supplied async function `fn` that has a standard JS callback `(error: Error, result: any)` into a `Promise`, passing the supplied parameters. When `error` is set, the Promise is rejected, else the Promise resolves with the `result` value.
|
|
* @example
|
|
* <BR>
|
|
*
|
|
* ```javascript
|
|
* const { promisify } from '@polkadot/util';
|
|
*
|
|
* await promisify(null, ((a, cb) => cb(null, a), true); // resolves with `true`
|
|
* await promisify(null, (cb) => cb(new Error('error!'))); // rejects with `error!`
|
|
* ```
|
|
*/
|
|
// eslint-disable-next-line @typescript-eslint/no-explicit-any
|
|
export default function promisify <R = any> (self: unknown, fn: (...params: any) => any, ...params: any[]): Promise<R> {
|
|
return new Promise((resolve, reject): void => {
|
|
const handler = (error: Error | null, result?: R): void => {
|
|
if (error) {
|
|
reject(error);
|
|
} else {
|
|
resolve(result);
|
|
}
|
|
};
|
|
|
|
fn.apply(self, params.concat(handler));
|
|
});
|
|
}
|