Update CancelableOperation test to not assume completion happens synchronously.
#203
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natebosch
reviewed
Mar 4, 2022
| @@ -460,8 +460,10 @@ void main() { | |||
| var operation = runThen(); | |||
| var workCompleter = Completer<int>(); | |||
| originalCompleter.complete(workCompleter.future); | |||
| originalCompleter.operation.cancel(); | |||
| var cancelation = originalCompleter.operation.cancel(); | |||
| expect(originalCompleter.isCanceled, true); | |||
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How does isCanceled become true synchronously here while we had to add the await above?
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The isCanceled of the operation you cancel gets set immediately.
Then the cancellation propagates asynchronously to .then listeners, which is what the other test checks (operation.isCanceled vs originalCompleter.operation.isCanceled.)
natebosch
approved these changes
Mar 8, 2022
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A bug in
Completer.completecould allow the completion to happen synchronously, even on a non-synchronous completer.That is being fixed in the SDK.
That affects
AsyncMemoizer, which uses a pattern which could trigger the bug.The
CancelableOperationcompleter uses such a memoizer and that would cause acancelto trigger.thenlisteners synchronusly.With that no longer being the case, two tests needed to insert delays to wait for the cancellation to be propagated to the listner.