import { reduce } from './reduce';
import { OperatorFunction } from '../types';
import { operate } from '../util/lift';
const arrReducer = (arr: any[], value: any) => (arr.push(value), arr);
/**
* Collects all source emissions and emits them as an array when the source completes.
*
* Get all values inside an array when the source completes
*
* 
*
* `toArray` will wait until the source Observable completes before emitting
* the array containing all emissions. When the source Observable errors no
* array will be emitted.
*
* ## Example
* ```ts
* import { interval } from 'rxjs';
* import { toArray, take } from 'rxjs/operators';
*
* const source = interval(1000);
* const example = source.pipe(
* take(10),
* toArray()
* );
*
* const subscribe = example.subscribe(val => console.log(val));
*
* // output: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
* ```
*
* @return A function that returns an Observable that emits an array of items
* emitted by the source Observable when source completes.
*/
export function toArray(): OperatorFunction {
// Because arrays are mutable, and we're mutating the array in this
// reducer process, we have to escapulate the creation of the initial
// array within this `operate` function.
return operate((source, subscriber) => {
reduce(arrReducer, [] as T[])(source).subscribe(subscriber)
});
}