puppeteer/packages/puppeteer-core/src/util/AsyncIterableUtil.ts

57 lines
1.5 KiB
TypeScript

/**
* Copyright 2023 Google Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import {type AwaitableIterable} from '../common/types.js';
/**
* @internal
*/
export class AsyncIterableUtil {
static async *map<T, U>(
iterable: AwaitableIterable<T>,
map: (item: T) => Promise<U>
): AsyncIterable<U> {
for await (const value of iterable) {
yield await map(value);
}
}
static async *flatMap<T, U>(
iterable: AwaitableIterable<T>,
map: (item: T) => AwaitableIterable<U>
): AsyncIterable<U> {
for await (const value of iterable) {
yield* map(value);
}
}
static async collect<T>(iterable: AwaitableIterable<T>): Promise<T[]> {
const result = [];
for await (const value of iterable) {
result.push(value);
}
return result;
}
static async first<T>(
iterable: AwaitableIterable<T>
): Promise<T | undefined> {
for await (const value of iterable) {
return value;
}
return;
}
}