Multiple useRequestPreSend: Should async event callbacks be awaited?

[leomelzer]

Hello!

Thanks for making and maintaining react-uploady, it's a joy to use!

I implemented signing with S3 parameters using useRequestPreSend and wanted to add client-side image compression to my pipeline. For that I simply created another useRequestPreSend before the signing one returning my altered items.

However it turned out my compressed images weren't being used for uploading...after some digging it turns out the registered events in life-events are in fact executed (or rather kicked-off) in sequence but the result not awaited.

Relevant code: https://github.com/rpldy/react-uploady/blob/master/packages/core/life-events/src/lifeEvents.js#L142-L166

I would have expected something like

results = regs.map(async (r: RegItem): any => {
            let result;

            if (r.once) {
                removeRegItem(this, name, r.cb);
			}

			if (packValue) {
                result = r.cb(...packValue);
            } else if (!args.length) {
				result = r.cb();
			} else {
				result = r.cb(...args);
			}

			return await result;
		})
			.filter((result: any): any => !isUndefined(result))
			.map((result: any): Promise<any> => isPromise(result) ? result : Promise.resolve(result));

I can see both sides so unsure whether this is in fact a bug or rather a conscious design decision.

For now I'll roll my code into one useRequestPreSend which is completely fine. I just figured I share this for future readers.

Thank you!

[yoavniran]

thanks @leomelzer
Indeed this was a design decision regarding how to handle pub/sub within Uploady.

And as you mentioned, a single callback to handle these two aspects is the recommended way.