Flaky test: ComposeMaskingOptionsTest "when sentry-unmask modifier is set unmasks the node"

[runningcode]

Summary

ComposeMaskingOptionsTest > when sentry-unmask modifier is set unmasks the node fails intermittently on main with:

java.lang.AssertionError: Node with text null should be masked
    at io.sentry.android.replay.viewhierarchy.ComposeMaskingOptionsTest.kt:238

(:sentry-android-replay:testReleaseUnitTest, Java 17 build job.)

Evidence it's flaky, not a regression

• Same test, same assertion failed on two unrelated commits while commits in between passed:
  • Jun 22, commit 0c118e90 — https://github.com/getsentry/sentry-java/actions/runs/27941528687/job/82675843497
  • Jun 18, commit f6192aac — https://github.com/getsentry/sentry-java/actions/runs/27750608535
• Both failures are preceded by a JVM instrumentation-agent error in the same run:
  *** java.lang.instrument ASSERTION FAILED ***: "!errorOutstanding" ... transform method call failed at .../JPLISAgent.c line: 876

Likely mechanism

In ComposeViewHierarchyNode.fromComposeNode (ComposeViewHierarchyNode.kt:178-189), masking is gated on visibility:

val isVisible =
  !SentryLayoutNodeHelper.isTransparent(node) &&
    (semantics == null || !semantics.contains(InvisibleToUser)) &&
    visibleRect.height > 0 && visibleRect.width > 0
...
val shouldMask = isVisible && semantics.shouldMask(isImage = false, options)

visibleRect comes from node.coordinates.boundsInWindow(...). If a node's bounds resolve to empty (width/height == 0), isVisible is false and the node is not masked even with maskAllText = true — exactly the failing assertion (the activity-title node, whose layout isn't a ComposeTextLayout, hence text == null).

Under Robolectric, Compose layout/coordinate resolution after shadowOf(Looper.getMainLooper()).idle() is timing-sensitive; when layout hasn't fully settled (occasionally perturbed by the instrumentation-agent transform failures above), boundsInWindow returns empty bounds → isVisible = false → node not masked → intermittent failure.

Possible fixes

• Await/assert non-empty bounds for the laid-out nodes before running the masking assertions.
• Make the masking assertions robust to the non-Compose activity-title node.
• Investigate the java.lang.instrument transform failure, which may be aggravating layout timing.

Unrelated to the MediaMuxer leak tracked in #5584 / PR #5583.

[linear-code]

JAVA-581

[runningcode]

I've created a reproduction for this issue: getsentry/repro#51

A key finding: the test passes 100% of the time when run in isolation, but flakes (~10% in my runs) when the whole ComposeMaskingOptionsTest class runs — so the flake is driven by test-interaction / Robolectric layout-timing within the class, consistent with the boundsInWindow → empty bounds → isVisible = false mechanism described above.

The repro is a loop runner (sentry-java/5585/run-repro.sh) that runs the full class N times with --rerun-tasks and tallies PASS/FAIL. Reproduced on a50df631e0 (main) with JDK 17, e.g. PASS=7 FAIL=1 (of 8).

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