You signed in with another tab or window. Reload to refresh your session.You signed out in another tab or window. Reload to refresh your session.You switched accounts on another tab or window. Reload to refresh your session.Dismiss alert
Introduces proper handling for Bazel's JUnit tests runner suite events by:
Removing the previous temporary solution of lazy starting suites.
Introduces a new instrumentation for fireTestSuiteStarted and fireTestSuiteFinished methods to unwrap the notifiers and propagate the firing to our tracing listener.
Motivation
Bazel's default JUnit4 configuration for running test suites introduces changes that mess with our instrumentation:
Bazel's JUnit entry-point is through BazelTestRunner.main(), which builds a JUnit4Runner (does not inherit org.junit.runner.Runner) and calls run().
JUnit4Runner.run() instantiates JUnitCore, registers its run listeners and calls core.run(cancellableRequest).
JUnitCore creates a fresh RunNotifier (from now on A) and registers the listeners on it.
The request is run with a custom CancellableRunner (extends org.junit.runner.Runner). Its run(A) does currentNotifier = new ThreadSafeRunNotifier(A); delegate.run(currentNotifier);.
ThreadSafeRunNotifier extends RunNotifierWrapper extends RunNotifier, so currentNotifier (from now on B) has its own private inherited listeners field.
The real runner.run(B) executes.
Our instrumentation modifies the call to do B.addListener(tracingListener), but Bs implementation overrides the method to call delegate.addListener(tracingListener); so our listener lands on A.listeners.
The real runner fires events such as test suite starts with B.fireTestSuiteStarted(...).
The wrapper does not override test suite methods, so it is resolved as RunNotifier.fireTestSuiteStarted(...) invoked with this = B. This iterates over B.listeners, which is empty.
The wrapper does forward regular test events with delegate.fireTest...(...) by overriding the methods
Note:Once your PR is ready to merge, add it to the merge queue by commenting /merge./merge -c cancels the queue request. /merge -f --reason "reason" skips all merge queue checks; please use this judiciously, as some checks do not run at the PR-level. For more information, see this doc.
daniel-mohedano
changed the title
fix: proper handling of bazel test runner suite events
Update JUnit4 instrumentation to fire test suite events for Bazel
May 11, 2026
2026-05-12 07:20:26 UTC ℹ️ Start processing command /merge
2026-05-12 07:20:36 UTC ℹ️ MergeQueue: waiting for PR to be ready
This pull request is not mergeable according to GitHub. Common reasons include pending required checks, missing approvals, or merge conflicts — but it could also be blocked by other repository rules or settings.
It will be added to the queue as soon as checks pass and/or get approvals. View in MergeQueue UI. Note: if you pushed new commits since the last approval, you may need additional approval.
You can remove it from the waiting list with /remove command.
2026-05-12 07:49:22 UTC⚠️MergeQueue: This merge request was unqueued
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
daniel-mohedano
added
type: bug
What Does This Do
fireTestSuiteStartedandfireTestSuiteFinishedmethods to unwrap the notifiers and propagate the firing to our tracing listener.Motivation
Bazel's default JUnit4 configuration for running test suites introduces changes that mess with our instrumentation:
BazelTestRunner.main(), which builds aJUnit4Runner(does not inheritorg.junit.runner.Runner) and callsrun().JUnit4Runner.run()instantiatesJUnitCore, registers its run listeners and callscore.run(cancellableRequest).JUnitCorecreates a freshRunNotifier(from now on A) and registers the listeners on it.CancellableRunner(extendsorg.junit.runner.Runner). Itsrun(A)doescurrentNotifier = new ThreadSafeRunNotifier(A); delegate.run(currentNotifier);.ThreadSafeRunNotifier extends RunNotifierWrapper extends RunNotifier, socurrentNotifier(from now on B) has its own private inheritedlistenersfield.runner.run(B)executes.B.addListener(tracingListener), butBs implementation overrides the method to calldelegate.addListener(tracingListener);so our listener lands onA.listeners.B.fireTestSuiteStarted(...).RunNotifier.fireTestSuiteStarted(...)invoked withthis = B. This iterates overB.listeners, which is empty.delegate.fireTest...(...)by overriding the methodsAll this caused test suite events to be dropped.
Additional Notes
test-environment-trigger: skip
Contributor Checklist
type:and (comp:orinst:) labels in addition to any other useful labelsclose,fix, or any linking keywords when referencing an issueUse
solvesinstead, and assign the PR milestone to the issueJira ticket: [PROJ-IDENT]
Note: Once your PR is ready to merge, add it to the merge queue by commenting
/merge./merge -ccancels the queue request./merge -f --reason "reason"skips all merge queue checks; please use this judiciously, as some checks do not run at the PR-level. For more information, see this doc.