관리-도구

편집 파일: reject.js

import {
  noop,
  reject as _reject
} from '../-internal';

/**
  `Promise.reject` returns a promise rejected with the passed `reason`.
  It is shorthand for the following:

```javascript
  let promise = new Promise(function(resolve, reject){
    reject(new Error('WHOOPS'));
  });

promise.then(function(value){
    // Code here doesn't run because the promise is rejected!
  }, function(reason){
    // reason.message === 'WHOOPS'
  });
  ```

Instead of writing the above, your code now simply becomes the following:

```javascript
  let promise = Promise.reject(new Error('WHOOPS'));

promise.then(function(value){
    // Code here doesn't run because the promise is rejected!
  }, function(reason){
    // reason.message === 'WHOOPS'
  });
  ```

@method reject
  @static
  @param {Any} reason value that the returned promise will be rejected with.
  Useful for tooling.
  @return {Promise} a promise rejected with the given `reason`.
*/
export default function reject(reason) {
  /*jshint validthis:true */
  let Constructor = this;
  let promise = new Constructor(noop);
  _reject(promise, reason);
  return promise;
}