I'm using a library called sqs-consumer to process SQS messages. The library is expecting the message handler to look like:
handleMessage: (message, done) => {
// do some work with `message`
done();
}
On the other hand though I have async code
async function sendEmail() {
return await ...
}
Is there a good way to run the sendEmail within handleMessage, wait for it to finish, and then to call done?
You can use your promise-based code inside a callback like this:
handleMessage: (message, done) => {
// do some work with `message`
sendEmail().then(done).catch(...);
}
In some cases, you could also make a new method for handleMessage() that actually expects a promise to be returned and works with that promise directly rather than using a plain callback at all.
Also, not that there is no point to using return await ... at the end of your function. You can just return the promise directly:
So, instead of:
async function sendEmail() {
// other code here
return await someFuncThatReturnsPromise();
}
You can just do:
async function sendEmail() {
// other code here
return someFuncThatReturnsPromise();
}
That extra await adds no value or utility.
As long as the library doesn't care what you return from handleMessage you can also use async/await in the handlerMessage function directly:
handleMessage: async (message, done) => {
await sendEmail();
done();
}
return awaitis pretty pointless if that's the onlyawaityou're using in the function - just use a standard function instead, and you can simplyreturnthe plainPromise