[ECO-5149] Implement lifecycle contributor precedence

[lawrence-forooghian]

Implements spec points CHA-RC2e and CHA-RL10.

Resolves #153.

Summary by CodeRabbit

• New Features

  • Enhanced error handling for room features, ensuring clarity when accessing properties without enabled features.
  • Reintroduction of the typing feature in the room feature set.

• Bug Fixes

  • Improved initialization process for room contributors, ensuring correct order of feature processing.

• Tests

  • Added a new test to verify the order of contributors in the DefaultRoom when all features are enabled, enhancing test coverage.

[coderabbitai]

Walkthrough

The pull request introduces modifications to the Room protocol and its implementations, enhancing the handling of room features and their dependencies. Notable changes include the introduction of error handling mechanisms for accessing properties without enabled features, updates to the initialization process in DefaultRoom, and the addition of a new static method in RoomFeature. A new test method is also introduced to verify the order of contributors in the RoomLifecycleManager, ensuring compliance with specified requirements.

Changes

File	Change Summary
Sources/AblyChat/Room.swift	Updated Room protocol and DefaultRoom class; refined feature handling and error management.
Sources/AblyChat/RoomFeature.swift	Modified RoomFeature enum to conform to CaseIterable; added method for precedence checking.
Tests/AblyChatTests/DefaultRoomTests.swift	Added lifecycleContributorOrder() test method to validate contributor order in lifecycle.

Assessment against linked issues

Objective	Addressed	Explanation
Implement lifecycle contributor precedence (#153)	✅

Possibly related PRs

• Add an “all features enabled” room option #170: Introduces a new static property allFeaturesEnabled in RoomOptions, enhancing the usability of room configurations related to feature handling.
• [ECO-5148] Implement “async room get” spec points #171: Modifies error handling and room state management, aligning with improvements in handling room features and dependencies.

Suggested reviewers

• umair-ably
• maratal
• AndyTWF

Poem

In the room where features play,
Order reigns, come what may.
With typing back, and reactions too,
The lifecycle flows, all bright and new.
Errors caught, no more dismay,
Hooray for changes, hip-hip-hooray! 🐇✨

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[coderabbitai]

Actionable comments posted: 2

🧹 Outside diff range and nitpick comments (1)

Sources/AblyChat/RoomFeature.swift (1)

4-8: Consider Assigning Explicit Raw Values to Enum Cases

Relying on the order of enum cases for precedence can lead to maintenance issues if the order is changed unintentionally. Assigning explicit raw values to RoomFeature cases will make the precedence explicit and the code more robust.

Apply this diff to assign explicit raw values:

-import Ably

/// The features offered by a chat room.
-internal enum RoomFeature: CaseIterable {
+internal enum RoomFeature: Int, CaseIterable {
    // This list MUST be kept in the same order as the list in CHA-RC2e, in order for the implementation of `areInPrecedenceListOrder` to work.
-   case messages
-   case presence
-   case typing
-   case reactions
-   case occupancy
+   case messages = 0
+   case presence = 1
+   case typing = 2
+   case reactions = 3
+   case occupancy = 4

And update areInPrecedenceListOrder:

/// Returns a `Bool` indicating whether `first` and `second` are in the same order as the list given in CHA-RC2e.
 internal static func areInPrecedenceListOrder(_ first: Self, _ second: Self) -> Bool {
-    let allCases = Self.allCases
-    let indexOfFirst = allCases.firstIndex(of: first)!
-    let indexOfSecond = allCases.firstIndex(of: second)!
-    return indexOfFirst < indexOfSecond
+    return first.rawValue < second.rawValue
 }

📜 Review details

Configuration used: CodeRabbit UI
Review profile: CHILL

📥 Commits

Reviewing files that changed from the base of the PR and between 2b2bfc0 and 90f436b.

📒 Files selected for processing (3)

• Sources/AblyChat/Room.swift (2 hunks)
• Sources/AblyChat/RoomFeature.swift (2 hunks)
• Tests/AblyChatTests/DefaultRoomTests.swift (1 hunks)

🔇 Additional comments (1)

Sources/AblyChat/Room.swift (1)

Line range hint 215-250: Ensure Correct Ordering of Features According to Precedence

The sorting logic in createFeatureChannelPartialDependencies uses RoomFeature.areInPrecedenceListOrder to determine the order of contributors. Please verify that the comparison function correctly implements the precedence as per the CHA-RC2e specification. This ensures that features are processed in the intended sequence, preventing potential unintended behavior.

[maratal]

LGTM