Steps to reproduce the problem

1. Run the function clearStorageArtefacts() (see implementation below)

2. Check if storage is restored correctly.

3. Some users experience data loss, but the exact conditions remain unclear.

Problem Description

After deploying an update to our Chrome extension, we received reports from users—primarily on Windows—indicating that their extension storage was wiped out after executing the following function which we introduced in a latest update:

export async function clearStorageArtefacts() {
  const everything = await browser.storage.local.get(null);
  await browser.storage.local.clear(); // this removes local extension files
  await browser.storage.local.set(everything); // store everything back
}

This function was introduced in order to clear storage state snapshot from the 000003.log file

This function was tested internally and worked as expected, preserving storage data after clearing and resetting. However, post-release, some users experienced permanent data loss, suggesting that either browser.storage.local.get(null) might not have retrieved all stored data or that the line after clear failed to execute. Or another hypothesis is that the prev version of the service worker interfered with the execution of the new one.

Expected Behavior: Storage data should be restored after the clearing operation.

Actual Behavior: Some users (primarily on Windows) reported that their storage was wiped out and not restored.

We could not reproduce the issue internally on Windows 11, making this a difficult issue to isolate. Could this be filesystem-related on Windows (e.g., permission issues, delayed writes)?

I would appreciate any investigation into this issue, as it has resulted in user data loss for some affected users.

Additional Comments

I will try to collect Chrome versions from the users who are reporting this

Summary

Unexpected Data Loss when clearing and restoring Extension Storage

Custom Questions

Which component does this fall under?

Not sure - I don't know

Does this work in other browsers?

Not sure - I don't know

Additional Data

Category: API
Chrome Channel: Stable
Regression: N/A