Fix strong reference cycle between RoomProxy and RoomTimelineProvider

[Johennes]

Fixes: #216

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Codecov Report

Base: 11.79% // Head: 11.79% // No change to project coverage 👍

Coverage data is based on head (fe37775) compared to base (98de776).
Patch has no changes to coverable lines.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop     #217   +/-   ##
========================================
  Coverage    11.79%   11.79%           
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  Files          213      213           
  Lines        14359    14359           
  Branches      6974     6974           
========================================
  Hits          1693     1693           
  Misses       12623    12623           
  Partials        43       43           

Impacted Files	Coverage Δ
ElementX/Sources/Services/Room/MockRoomProxy.swift	0.00% <ø> (ø)
...entX/Sources/Services/Room/RoomProxyProtocol.swift	0.00% <ø> (ø)
...urces/Services/Timeline/RoomTimelineProvider.swift	0.00% <ø> (ø)

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[stefanceriu]

I'm not quite sure I follow this one: the roomProxy is a direct dependency of the TimelineProvider and should be strongly retained by it. If there's a cycle it should be handled another way.

LE: I had a closer look at it, we need to take the timelineProvider out of the roomProxy and create it when needed in the AppCoordinatorUserSessionFlowCoordinator. The timelineProvider can register itself as a listener on its own roomProxy dependency.

[Johennes]

I'm not quite sure I follow this one: the roomProxy is a direct dependency of the TimelineProvider and should be strongly retained by it. If there's a cycle it should be handled another way.

Johannes tries to get weird retain cycle context from last night back into his head. 😅

I think they're mutual dependencies, right? The reason I made the reference in RoomTimelineProvider the weak one is that RoomTimelineProvider seems to only ever be created (and retained) in RoomProxy. RommProxy, on the other hand, is created and returned in ClientProxy so I assumed this was the object the caller would retain.

LE: I had a closer look at it, we need to take the timelineProvider out of the roomProxy and create it when needed in the AppCoordinatorUserSessionFlowCoordinator. The timelineProvider can register itself as a listener on its own roomProxy dependency.

That might be a better solution altogether. I'll have to return to this after hours.

[stefanceriu]

Yeah, the RoomProxy used to create the timelineProvider and retain it itself. I fixed it here if you want to have a look /pull/220

[Johennes]

Discarding this over #220.