StreamGroup.merge([1st ,2nd]) doesn't merge the two streams. but instead returns the 2nd stream about async HOT 5 CLOSED

We have a test covering this - there is not problem in general merging two streams.

Perhaps your stream is a broadcast Stream? Those events are explicitly not buffered and so any events that come through before you have a listener on the group's stream will be lost.

You might find the SingleSubscriptionStreamTransformer useful to convert a broadcast Stream to a single subscription stream and buffer events until there is a listener.

from async.

this this stackoverflow tracks the issue https://stackoverflow.com/questions/51214217/combine-streams-from-firestore-in-flutter

from async.

Turns out that this issue also affects the RX Observable
https://stackoverflow.com/questions/51368676/flutter-stream-builder-does-not-work-correctly-when-it-is-fed-with-observable1/52843628#52843628

from async.

Turns out that this issue also affects the RX Observable

Note that package:rxdart does not depend on package:async and has a completely independent implementation. If there were a bug here it would not impact that package. This is another signal that the problem is coming from the input streams, not the merging.

from async.

Update, Observable did pass both stream contents to the function as tested with
streamGroup.map((convert){ convert.documents.forEach((f){print(f.data["name"]);});}).listen(print);
however the Flutter streamBuilder widget failed to update the UI with both values.
Conclusion issue is not in the stream merging, but in displaying the content to the UI.
Thanks @natebosch for your timely response.

from async.