具有async/await样式功能的async.queue [英] async.queue with async/await style functions

问题描述

我正在尝试创建一个函数，该函数从对象数组构建队列，然后通过调用多个函数来处理每个对象.

处理功能是异步功能，在需要排队之前，我已经使用async/await模式实现了.我认为这是必要的，因为每个人都依赖于前一个的输出，并且我不想有大量的嵌套承诺.

即以前我有:

await Promise.all(messages.map(async(message) => {
    let activity = await activityController.getActivity(message.activityId);
    let url = await SMSController.getUrl(message.Token);
    let smsSendResult = await SMSController.sendSMS(messageString, activity.mobileNo);
    // etc...
}

现在我想做的是:

let queue = async.queue((message, done) => {
     let activity = await activityController.getActivity(message.activityId);
     let smsSendResult = await SMSController.sendSMS(messageString, activity.mobileNo);
    // etc...
}

messages.forEach((message) => {
    queue.push(message);
})

我有一个问题，尽管这样会导致

SyntaxError: await is only valid in async function

而且我似乎不太了解如何克服这个问题.

解决方案

我在async模块中找到了asyncify函数，该函数允许我执行以下操作:

var queue = async.queue(async.asyncify(async (message, done) => {
    let url = await SMSController.getUrl(message.token);
    // etc...
}

I'm trying to create a function that builds a queue from an array of objects and then processes each object by calling a number of functions.

The processing functions are asynchronous functions which, prior to needing to queue, I'd implemented using the async/await pattern. I think this is necessary as each relies on the output of the previous and I don't want to have a tonne of nested promise.then's

i.e. previously I had:

await Promise.all(messages.map(async(message) => {
    let activity = await activityController.getActivity(message.activityId);
    let url = await SMSController.getUrl(message.Token);
    let smsSendResult = await SMSController.sendSMS(messageString, activity.mobileNo);
    // etc...
}

Now what I want to be able to do is:

let queue = async.queue((message, done) => {
     let activity = await activityController.getActivity(message.activityId);
     let smsSendResult = await SMSController.sendSMS(messageString, activity.mobileNo);
    // etc...
}

messages.forEach((message) => {
    queue.push(message);
})

I have the problem though that this results in

SyntaxError: await is only valid in async function

And I can't seem to quite get my head around how to get past this.

解决方案

I found the asyncify function in the async module which allows me to do this:

var queue = async.queue(async.asyncify(async (message, done) => {
    let url = await SMSController.getUrl(message.token);
    // etc...
}

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