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fix(replay): Distinguish worker load failures from page-teardown aborts - #22378
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billyvg wants to merge 1 commit into
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fix(replay): Distinguish worker load failures from page-teardown aborts#22378billyvg wants to merge 1 commit into
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The "Failed to load Replay compression worker: Unknown error" message is captured across Chrome, Edge and Firefox as well as Safari. On those engines the blob MIME type is irrelevant — the error comes from the worker fetch being aborted when the page navigates away or is backgrounded while the worker is still loading. `WorkerHandler.ensureReady()` now routes the worker `error` event through a helper that distinguishes an aborted load (document hidden/unloading) from a genuine load failure, so the captured message is accurate instead of always blaming CSP/network.
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size-limit report 📦
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billyvg
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Jul 20, 2026
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dont think this is needed |
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Summary
Follow-up to #22377 (the Safari MIME fix). This addresses the cross-browser occurrences of the same captured error:
The MIME fix only explains the Safari subset. The
browser.namebreakdown on the dogfood issue shows the error is cross-engine:Blink/Gecko don't reject the blob MIME type, so those events have a different cause: the worker fetch is aborted when the page navigates away / is backgrounded while the worker is still loading. The breadcrumbs consistently show
fetchaborts (status: None) plusTypeError: Load failed(Safari) /can't access dead object(Firefox) right before the failure — the signature of navigation-time teardown.WorkerHandler.ensureReady()'serrorhandler now routes through_getWorkerLoadError(), which distinguishes:ErrorEventwith a message → use it verbatim,This is a handled error (recording already falls back to the uncompressed buffer), so there's no behavior change beyond a more accurate captured message.
Risk
Higher than #22377 — it changes the error message for some genuine load failures that happen while a tab is hidden (they'll now read "page was hidden or unloaded" instead of the CSP/network catch-all). The hidden-document case is overwhelmingly teardown, but flagging for reviewer judgment. If we'd rather keep capturing those unchanged and only relabel navigation aborts, that's a small tweak.
Testing
ensureReadycases inWorkerHandler.test.tscover theErrorEvent.message, hidden-document (teardown), and visible-document (generic) branches.oxlint+oxfmtclean; eventBuffer suite (28) passes.