Users have seen event being sent *during* the `listen` call
to the underlying stream. This caught the `StreamIterator`
in an unanticipated state (subscription wasn't available yet).
Sending events during a `listen` call can currently happen
using a synchronous broadcast stream controller adding
events in the `onListen` callback.
That should be fixed so that broadcast stream subscriptions
are treated as paused during the `onListen` call like
single-subscription streams already are.
This change hardens the class against that particular malpratice,
but it's still possible to get into inconsistent states if the
`listen` call somehow manages to call back into the same
stream-iterator again. So, don't do that.
(The class also assumes that no stream will send events/call callbacks
* while paused.
* after cancelling
* after a done event
* while delivering another event.
If a stream does so, things will still crash.
It is believed that no platform stream will do any of these.)
Fixes#43779.
BUG= http://dartbug.com/43779
Change-Id: If47065cfa9a1115425fdf51b147f2ed7154fef99
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/167800
Reviewed-by: Nate Bosch <nbosch@google.com>
Reviewed-by: Lasse R.H. Nielsen <lrn@google.com>
Commit-Queue: Lasse R.H. Nielsen <lrn@google.com>
This allows to break a circular dependency between package:expect and
package:async_helper, which will simplify the support for modular tests using
package:modular_test.
Change-Id: Ie48723d3f35d51a8fbe622e0158450e8104fe3f5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/102140
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Add simplified unittest replacement to package:expect.
(It is used in multi-tests, so it needs to be in an accessible place without using ".." in its path).
Change-Id: I60aa212ed67ffbdda17ca18fce1cdff16237f4fe
Reviewed-on: https://dart-review.googlesource.com/65700
Commit-Queue: Lasse R.H. Nielsen <lrn@google.com>
Reviewed-by: Jenny Messerly <jmesserly@google.com>
Since unittest is known to work with test.dart as a test runner and is
strong mode clean, it's a safer bet than test.
Change-Id: Id120d4f871827b1f131dff2a5ef2f7efb15a8382
Reviewed-on: https://dart-review.googlesource.com/12125
Reviewed-by: Terry Lucas <terry@google.com>
Lasse R.H. Nielsen