如何正确处理打字稿中的 promisifyAll？

Question

考虑以下代码：

import redis = require('redis');  //Has ambient declaration from DT
import bluebird = require('bluebird');  //Has ambient declaration from DT

bluebird.promisifyAll((<any>redis).RedisClient.prototype);
bluebird.promisifyAll((<any>redis).Multi.prototype);

const client = redis.createClient();

client.getAsync('foo').then(function(res) {
    console.log(res);
});

getAsync 会出错，因为它是动态创建的，没有在任何 .d.ts 文件中定义。那么处理这个问题的正确方法是什么？

此外，即使我为 redis 加载了 .d.ts 文件，我仍然需要将 redis 转换为 any 以用于 promisifyAll。否则会溢出error:

Property 'RedisClient' does not exist on type 'typeof "redis"'

输入 any 是唯一简单的方法吗？

Answer 1

我正在通过 declaration merging setAsync 和 getAsync 方法解决这个问题。我在自己的自定义 .d.ts 文件中添加了以下代码。

declare module "redis" {

    export interface RedisClient extends NodeJS.EventEmitter {
        setAsync(key:string, value:string): Promise<void>;
        getAsync(key:string): Promise<string>;
    }

}

Answer 2

只是添加到 Dave 的答案中，根据我的需要，我必须添加 Multi 以进行原子操作。

declare module 'redis' {
    export interface RedisClient extends NodeJS.EventEmitter {
        execAsync(...args: any[]): Promise<any>;
        hgetallAsync(...args: any[]): Promise<any>;
        // add other methods here
    }
    export interface Multi extends Commands<Multi> {
        execAsync(...args: any[]): Promise<any>;
        // add other methods here
    }
}

Answer 3

另一种需要较少代码的方法是像这样扩展 Redis 对象：

import { promisify } from 'util';
import { ClientOpts, RedisClient } from 'redis';

class AsyncRedis extends RedisClient {
  public readonly getAsync = promisify(this.get).bind(this);
  public readonly setAsync = promisify(this.set).bind(this);
  public readonly quitAsync = promisify(this.quit).bind(this);
  public readonly rpushAsync: (list: string, item: string) => Promise<number> = promisify(
    this.rpush
  ).bind(this);
  public readonly blpopAsync: (
    list: string,
    timeout: number
  ) => Promise<[string, string]> = promisify(this.blpop).bind(this);
  public readonly flushdbAsync = promisify(this.flushdb).bind(this);
}

请注意，并非所有方法签名都能正确覆盖，因此您必须稍微帮助打字稿。

现在您可以使用这个增强的 class 通过使用您的选项创建它，例如：

new AsyncRedis({
  host: process.env.REDIS_HOST || '127.0.0.1',
  password: process.env.REDIS_PASSWORD || 'whatever',
 });

Answer 4

这个解决方案对我来说很好用：

import { promisifyAll } from 'bluebird'; // import here works only if @types/bluebird is installed
import redis, { RedisClient, Multi } from 'redis'; // import here works only if @types/redis is installed

// Convert Redis client API to use promises, to make it usable with async/await syntax
const MultiAsync: any = promisifyAll(Multi.prototype);
const RedisClientAsync: any = promisifyAll(RedisClient.prototype);
const redisAsync = { ...redis, Multi: MultiAsync, RedisClient: RedisClientAsync };

const client: typeof RedisClientAsync = redisAsync.createClient();
// now you can use client async methods, i.e. client.getAsync, client.hgetAsync, client.hsetAsync, client.expireAsync...

如何正确处理打字稿中的 promisifyAll？

How to properly deal with promisifyAll in typescript?

javascript

promise

typescript

bluebird