`dart pub global run coverage:test_with_coverage` sometimes never terminates with tests that use async

[benthillerkus]

Running dart pub global run coverage:test_with_coverage on this package https://github.com/benthillerkus/db_migrations_with_multiverse_time_travel/tree/main/packages/sqflite does not terminate.
The tests run through and the success message is displayed, but the process never stops and the coverage files are not being written to disk.
The problem is only with this package, with the other two packages the test runner finishes as expected. The only differentiator of this package is that it uses async in the tests.

This has caused me to write some convoluted code to not have the CI job fail, but it would be great if this just wasn't a problem.

I can reproduce this on my local Windows machine aswell as the Ubuntu CI runners

[liamappelbe]

How flaky is this issue? How often does it reproduce?
Also, what version of package:coverage are you using?

[benthillerkus]

How flaky is this issue? How often does it reproduce?

Always. Just clone the repo and run tests in the sqflite subfolder.

Also, what version of package:coverage are you using?

Newest, so coverage: ^1.11.1

---

git clone https://github.com/benthillerkus/db_migrations_with_multiverse_time_travel.git
cd db_migrations_with_multiverse_time_travel
dart pub get
dart pub global install coverage
cd packages/sqflite
dart pub global run coverage:test_with_coverage

[liamappelbe]

When I run the tests I get this error: Failed to load dynamic library 'libsqlite3.so'. Is there a setup command to build that library or something? I tried running sudo apt install sqlite3 but that didn't help.

I'm able to reproduce the hanging behavior either way, but do you expect the tests to pass otherwise?

[liamappelbe]

Actually, playing with the test a bit, I think the fact that the setUp function is throwing might be important. When I comment out all the lines that are reporting errors, the test completes successfully, regardless of which of the functions are marked async.

[benthillerkus]

When I run the tests I get this error: Failed to load dynamic library 'libsqlite3.so'. Is there a setup command to build that library or something? I tried running sudo apt install sqlite3 but that didn't help.

No, in theory sudo apt install sqlite3 should be enough

I'd expect the tests to pass, and they do pass; the hanging comes for me after the tests have passed.

[liamappelbe]

Looks like sqflite_common_ffi starts a helper isolate and never shuts it down. Package coverage is hanging and waiting for the background isolate to complete and enter a paused state so that it can collect coverage for that isolate.

In standalone Dart programs, helper isolates like that aren't an issue because the VM shuts down when the main isolate shuts down. So all background isolates are effectively terminated when the main isolate terminates. Maybe the fix is to adopt the same behavior in package:coverage? When the main isolate enters a paused state, collect its coverage and exit, ignoring all remaining isolates. Seems risky, so I'll need to think about the edge cases. Need to make sure we're not missing any coverage collections.