1826390 - Persistent state and prefs (e.g. extensions.webextensions.uuids) from generated test extensions are not cleaned up at extension.unload()

Status: RESOLVED FIXED

(WebExtensions :: General, defect, P2)

Description

[Rob Wu [:robwu]]

Ordinarily (outside of tests), when an extension is uninstalled, any remaining state is cleaned up in ExtensionAddonObserver.onUninstalled. This is triggered by the AddonManager internals.

In tests, when ExtensionTestUtils.loadExtension is used without useAddonManager, a bare Extension instance is created without the AddonManager. Consequently, the cleanup logic never runs. As a result, persistent state is never cleaned up:

• extensions.webextensions.uuids will continuously accumulate values for every new extension (bug 1363464).
  This is particularly problematic in mochitests, because eventually a ceiling will be reached on the permitted length of the pref value, e.g.: https://bugzilla.mozilla.org/show_bug.cgi?id=1611913#c1
• ExtensionPermissions is not cleared.
• Extension API state is not cleaned up (storage API, scripting API, DNR API).
• DOM state (cache, storage, permissions, service workers)

This can easily be observed when you run a mochitest with the --compare-preferences flag, as shown in https://bugzilla.mozilla.org/show_bug.cgi?id=1825953#c5 . This flag is enabled by default on TV builds.

Comment 1

[Rob Wu [:robwu]]

Attachment: Bug 1826390 - Make sure that post-uninstall cleanup runs for generated extensions in mochitests

Comment 2

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:willdurand, could you have a look please?

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Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:rpl, could you have a look please?

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Comment 4

[BugBot [:suhaib / :marco/ :calixte]]

There is an r+ patch which didn't land and no activity in this bug for 2 weeks.
:robwu, could you have a look please?
If you still have some work to do, you can add an action "Plan Changes" in Phabricator.
For more information, please visit BugBot documentation.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/707620083346
Make sure that post-uninstall cleanup runs for generated extensions in mochitests r=zombie

Comment 6

[Aron Cseh]

https://hg.mozilla.org/mozilla-central/rev/707620083346