test(replay): De-flake mutationLimit large-mutations test - #24784
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The `replay.mutations` breadcrumb is created asynchronously (once rrweb's
MutationObserver fires), while the incremental snapshots and `ui.click`
breadcrumb are buffered synchronously on the click. With the test's
`forceFlushReplay()` racing the force-flush from `stop({ reason:
'mutationLimit' })`, these can land in separate replay envelopes.
The test waited for the first request containing snapshots and asserted it
held both breadcrumbs, which failed whenever the mutation breadcrumb landed in
a later flush. Aggregate recording snapshots across requests via
`collectReplayRequests` until the mutation breadcrumb arrives instead.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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… envelope `collectReplayRequests` starts listening right after the setup `forceFlushReplay()`, which only awaits the in-page dispatch and not the resulting network request. A leftover in-flight envelope from the `#noop` setup click can therefore land in the collected set and re-deliver its `ui.click` breadcrumb, duplicating the category and breaking the exact-equality assertion. Assert on the unique categories instead. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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The
replay.mutationsbreadcrumb is created asynchronously — only once rrweb'sMutationObserverfires — whereas the incremental snapshots and theui.clickbreadcrumb are buffered synchronously on the click. Because the test'sforceFlushReplay()races the force-flush triggered bystop({ reason: 'mutationLimit' }), those events can be split across two separate replay envelopes.The test waited for the first request containing snapshots and asserted that single request held both
replay.mutationsandui.click. Whenever the mutation breadcrumb landed in the second flush, that first request only carried['ui.click'], producing the CI flake. The fix aggregates recording snapshots across requests via the existingcollectReplayRequestshelper, resolving once the mutation breadcrumb has arrived, so the assertions no longer depend on the flush split. Sinceui.clickis always buffered before the async mutation breadcrumb, it's guaranteed present in the aggregated set by then.Root cause: flush-ordering race between the test's manual flush and replay's stop-triggered force-flush.