PromiseQueue stopping when a promise is rejected.

[jayther]

I started using the utils/Async.PromiseQueue for an extension I'm creating (mostly for myself but will be available on GitHub when it's done). PromiseQueue is great, except when a promise in the queue is rejected, and then all of the potential promises in the queue are stuck and not run.

I took a look in the master branch code to look for the issue and indeed, in src/utils/Async in line 490, the PromiseQueue only attaches on the resolved state of the current promise ( .done() ). According to the JSDoc comment on top of .add(), the queue is supposed to go to the next promise regardless if the state of the current promise is resolved or rejected, meaning it should add itself to the current promise's .always().

For a quick fix in my extension, I extended the PromiseQueue to override the .add() function to use .always() instead of .done().

[njx]

Good catch - I think I wrote this code and have only ever used it in situations where promises are never rejected. Would you be interested in submitting a PR to fix it (and add tests for these cases in Async-test)? If not, no problem - we can take a look at it later.

[jayther]

Sure, I'll submit a PR to fix it tonight.

[njx]

Fixed by filer, closing.