How to make a http request in a flutter widget test?
If the cause of the issue is timeouts as you've mentioned, I suggest trying a different network during tests. WidgetTester shouldn't cause issues on HTTP Requests in Flutter Unit Tests. I tried the repro provided, but it worked fine on my tests.
For reference, here's the version of Flutter I'm running on: Flutter version 1.26.0-2.0.pre.281