dart-lang
collect_coverage errors when isolates are spawned by the Dart script
I have a Dart library that does code generation that I am unable to reliably gather coverage from. The library has tests that rely on the output of an isolate spawned during the testing process.
The tests work as follows
- Run code generation step
- Spawn isolate which executes tests on the generated code which verifies they are working correctly.
- If isolate returns without error the code generation worked, if there's an error then the code generation failed.
It appears that when running dart --observe=8000 tests/all.dart that the isolate being spawned by the test is waiting for a connection to the observe port before exiting.
Running pub global run coverage:collect_coverage --port=8000 -o coverage.json then causes the test to complete but then the following error occurs
JsonRpcError: VM must be paused (101)
dart:async _Completer.completeError
package:coverage/src/devtools.dart 227 _Connection._handleResponse
===== asynchronous gap ===========================
dart:io _WebSocketImpl.listen
package:coverage/src/devtools.dart 184 _Connection._Connection
package:coverage/src/devtools.dart 191 _Connection.connect.<async>
===== asynchronous gap ===========================
dart:async _asyncThenWrapperHelper
package:coverage/src/devtools.dart _Connection.connect
package:coverage/src/devtools.dart 93 VMService.connectToVMWebsocket.<async>
===== asynchronous gap ===========================
dart:async Future.Future.microtask
package:coverage/src/devtools.dart VMService.connectToVMWebsocket
package:coverage/src/devtools.dart 89 VMService.connect.<async>
===== asynchronous gap ===========================
dart:async Future.Future.microtask
package:coverage/src/devtools.dart VMService.connect
package:coverage/src/collect.dart 17 collect.<async>.<fn>
package:coverage/src/util.dart 38 retry.<async>.<fn>.<async>
===== asynchronous gap ===========================
package:coverage retry.<async>.<fn>
package:coverage/src/util.dart 17 retry.<async>._withTimeout
package:coverage/src/util.dart 35 retry.<async>
===== asynchronous gap ===========================
dart:async Future.Future.microtask
package:coverage/src/util.dart retry
package:coverage/src/collect.dart 16 collect.<async>
===== asynchronous gap ===========================
dart:async Future.Future.microtask
package:coverage/src/collect.dart collect
http://localhost:50032/collect_coverage.dart 21 main.<async>.<fn>.<async>
===== asynchronous gap ===========================
package:stack_trace Chain.capture
http://localhost:50032/collect_coverage.dart 20 main.<async>
After running the command multiple times the coverage.json appears to be generated.
I'm not sure if this is a problem due to how dart is invoked or if coverage should be doing something different.
My setup is
sdk 1.14.0-dev.6.0
coverage 0.7.2
Windows 7
The repository I stumbled upon the issue is https://github.com/dogma-dart/dogma-codegen/.
A smaller use case is https://github.com/dogma-dart/dogma-codegen-test which is used by the above project to do this workflow. It has a set of tests as well that will not work with the coverage library.
I did have success with this environment for other projects so I think this just revolves around the isolate handling.
@kevmoo
I can give it a go locally. I actually moved away from doing things this way because I migrated to build and because the bug was sitting here.
