fix(replay): Ensure replays contain canvas rendering when resumed after inactivity #18714
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inactivity Replays of apps that use canvas elements that are resumed after a long period of inactivity (for example when navigating away and back to a tab after 5 minutes) were previously broken. Replays contained all DOM elements, including the canvas, but the canvas would not have any of its rendering captured. This happens because before resuming from inactivity, `getCanvasManager` creates a new `CanvasManager` that is then passed to a promise resolve function that was already resolved beforehand. That leads to the new canvas manager not actually being used when returning from inactivity and thus having all rendering attempted to be captured from the previous canvas manager instead of the new one. For backwards compatibility, I kept the promise based approach around and added a second storage variable for the canvas manager. I attempted to create integration tests but was not able to reproduce this issue in an integration test so I opted for just a basic unit test. I did reproduce this issue in a sample app locally and captured two replays: 1) The [first replay](https://sentry-sdks.sentry.io/explore/replays/26cd46702dc448148c0c887edaa10aec/?playlistEnd=2026-01-07T13%3A05%3A52&playlistStart=2026-01-07T12%3A05%3A52&project=4507937458552832&query=&referrer=replayList) uses our CDN bundles and shows canvas rendering captured at first but missing towards the end of the replay. 2) The [second replay](https://sentry-sdks.sentry.io/explore/replays/765c4b98474242b0a0e690e16b59ab7f/?playlistEnd=2026-01-07T13%3A13%3A23&playlistStart=2026-01-07T12%3A13%3A23&project=4507937458552832&query=&referrer=replayList) uses bundles built from this PR and shows canvas rendering continues towards the end of the replay. Closes: #18682
This was referenced Jan 9, 2026
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Replays of apps that use canvas elements that are resumed after a long period of inactivity (for example when navigating away and back to a tab after 5 minutes) were previously broken.
Replays contained all DOM elements, including the canvas, but the canvas would not have any of its rendering captured.
This happens because before resuming from inactivity,
getCanvasManagercreates a newCanvasManagerthat is then passed to a promise resolve function that was already resolved beforehand. That leads to the new canvas manager not actually being used when returning from inactivity and thus having all rendering attempted to be captured from the previous canvas manager instead of the new one.For backwards compatibility, I kept the promise based approach around and added a second storage variable for the canvas manager.
I attempted to create integration tests but was not able to reproduce this issue in an integration test so I opted for just a basic unit test.
I did reproduce this issue in a sample app locally and captured two replays:
The first replay uses our CDN bundles and shows canvas rendering captured at first but missing towards the end of the replay.
The second replay uses bundles built from this PR and shows canvas rendering continues towards the end of the replay.
Closes: #18682