[stable20] Sharing acceptance tests failing quite consistently due to missing notification

[PVince81]

I've seen the sharing acceptance test fail on the same one in different PRs:

• [stable20] Make user list pagination more tolerant #25475
• [stable20] Fix duplicate tag info view registration #25477
• [stable20] Remove stray compiled assets #25480
• https://drone.nextcloud.com/nextcloud/server/1935/55/4

This is the result:

  Scenario: share a file with another user that needs to accept shares        # /drone/src/tests/acceptance/features/app-files-sharing.feature:23
    Given I act as John                                                       # ActorContext::iActAs()
    And I am logged in as the admin                                           # LoginPageContext::iAmLoggedInAsTheAdmin()
    And I act as Jane                                                         # ActorContext::iActAs()
    And I am logged in                                                        # LoginPageContext::iAmLoggedIn()
    And I visit the settings page                                             # SettingsMenuContext::iVisitTheSettingsPage()
    And I open the "Sharing" section                                          # AppNavigationContext::iOpenTheSection()
    And I disable accepting the shares by default                             # SettingsContext::iDisableAcceptingTheSharesByDefault()
    And I see that shares are not accepted by default                         # SettingsContext::iSeeThatSharesAreNotAcceptedByDefault()
    And I act as John                                                         # ActorContext::iActAs()
    And I rename "welcome.txt" to "farewell.txt"                              # FileListContext::iRenameTo()
    And I see that the file list contains a file named "farewell.txt"         # FileListContext::iSeeThatTheFileListContainsAFileNamed()
    When I share "farewell.txt" with "user0"                                  # FilesAppSharingContext::iShareWith()
    And I see that the file is shared with "user0"                            # FilesAppSharingContext::iSeeThatTheFileIsSharedWith()
    And I act as Jane                                                         # ActorContext::iActAs()
    And I open the Files app                                                  # FilesAppContext::iOpenTheFilesApp()
    And I see that the file list does not contain a file named "farewell.txt" # FileListContext::iSeeThatTheFileListDoesNotContainAFileNamed()
    And I accept the share for "/farewell.txt" in the notifications           # NotificationsContext::iAcceptTheShareForInTheNotifications()
      Notifications button in the header could not be found after 100 seconds (NoSuchElementException)
    And I open the Files app                                                  # FilesAppContext::iOpenTheFilesApp()
    Then I see that the file list contains a file named "farewell.txt"        # FileListContext::iSeeThatTheFileListContainsAFileNamed()
    And I open the details view for "farewell.txt"                            # FileListContext::iOpenTheDetailsViewFor()
    And I see that the details view is open                                   # FilesAppContext::iSeeThatTheDetailsViewIsOpen()
    And I open the "Sharing" tab in the details view                          # FilesAppContext::iOpenTheTabInTheDetailsView()
    And I see that the "Sharing" tab in the details view is eventually loaded # FilesAppContext::iSeeThatTheTabInTheDetailsViewIsEventuallyLoaded()
    And I see that the file is shared with me by "admin"                      # FilesAppSharingContext::iSeeThatTheFileIsSharedWithMeBy()

It seems the notification / button never appears.
Either the timeout is too low or there's something wrong with the notifications app or notification testing on stable20.

[PVince81]

• check if notifications app is properly installed and enabled by CI

[PVince81]

PR is here: #25492

I've also checked stable21 but there the branch is already adjusted.