Stop using Utils.runAsync

[kzar]

Background

With #7338 we're no longer able to use some browser APIs from our background page. One thing we can no longer provide therefore is the Utils.runAsync function.

What to change

Stop using Utils.runAsync, namely in adblockpluscore/lib/downloader.js

Integration notes

Remove Utils.runAsync() from lib/utils.js in adblockpluschrome.

Hints for testers

Same as #7376.

[mjethani]

I have looked into this and I would like to suggest the following:

1. In the download() method in lib/downloader.js in adblockpluscore, we return a promise that resolves or rejects when the download is complete or has failed; this would make it asynchronous anyway
2. We modify lib/subscriptionInit.js in adblockpluschrome and messageResponder.js in adblockplusui to do what formerly Utils.runAsync() would do for the case when the document is not in the ready state; adblockplusui would check the ready state, while adblockpluschrome would do the same for now but later switch to using ​ServiceWorkerContainer.ready or whatever other extension API is appropriate

[mjethani]

Replying to mjethani:

1. In the download() method in lib/downloader.js in adblockpluscore, we return a promise that resolves or rejects when the download is complete or has failed; this would make it asynchronous anyway

Just to be clear, it doesn't have to return the promise for the purpose of resolving this issue. It could just keep the promise internal. In fact it could just use setTimeout() with a timeout of 0 as Utils.runAsync() does.

I have to point this out because returning a promise would entail further changes in the _download() method's implementation to make sure everything resolves/rejects correctly.

[sebastian]

For reference, the logic in Utils.runAsync() was a workaround that makes sure to call the callback not before all background scripts have been loaded/executed. There is a good chance that this workaround is no longer necessary, as most of our code is bundled together with webpack, and it might have been a browser bug in the first place that deferred loading of background scripts.

[abpbot]

A commit referencing this issue has landed:
​Issue 7406 - Replace Utils.runAsync() with promise