fix: messages not being sent, waiting forever for decryption to finish - WPB-17866

[jullianm]

WPB-17866 [iOS] Not able to send messages on mobile data

Issue

Context: Messages are stuck forever in a sending state, no way to recover. Next messages can't be sent as well, stuck in same state.

We introduced in this PR a mechanism that waits for pending events to be decrypted before proceeding to message sending.

Specifically in MessageSender, we await for incrementalSyncObserver.waitUntilCanSendMessage() and it only gets through when finishing decrypting the pending events and setting the decryptionState to done at the IncrementalSyncObserver level.

Causes: The decryption state might never gets updated to .done hence blocking the message sender to proceed the message which can lead to the bugs mentioned here and here.

What happens after is that if we try to send a message again we'll be stuck in a loop in try await messageDependencyResolver.waitForDependenciesToResolve(for: message) where the dependencies never resolve specifically dependentObjectNeedingUpdateBeforeProcessing (code doc below) will never be nil, probably because the initial message was never really processed and it blocks the next messages.

/// Other entities which has to complete an update before this entity can be processed, i.e. another message /// needs to be sent first because it was scheduled for sending before this message.

Solution: Update the sync state whenever the sync is suspended or when an error occurs while pulling (and decrypting) pending events so we ensure the decryption state is changed to done so the MessageSender method is "unlocked" and the messages are sent or at least attempted to be sent.

Testing

Tested internally

• Comment out the code where the sync state is updated so the MessageSender gets stuck and the message not sent.
• try to send message again and again
• messages shows up as in sending state just like the screenshots from the Jira tickets

Checklist

• Title contains a reference JIRA issue number like [WPB-XXX].
• Description is filled and free of optional paragraphs.
• Adds/updates automated tests.

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UI accessibility checklist

If your PR includes UI changes, please utilize this checklist:

• Make sure you use the API for UI elements that support large fonts.
• All colors are taken from WireDesign.ColorTheme or constructed using WireDesign.BaseColorPalette.
• New UI elements have Accessibility strings for VoiceOver.

[github-actions]

Test Results

3 525 tests   3 499 ✅  4m 3s ⏱️
  564 suites     26 💤
    4 files        0 ❌

Results for commit 72c4951.

♻️ This comment has been updated with latest results.

[samwyndham]

Nice work!

[datadog-wireapp]

Datadog Report

Branch report: fix/messages-not-being-sent
Commit report: e5871c7
Test service: wire-ios-mono

✅ 0 Failed, 3497 Passed, 26 Skipped, 2m 4.59s Total Time

[netbe]

left a question and wonder if a unit test can be added

[jullianm]

added some UTs in last commit @netbe , merging the PR