Add CRDT clock and convergence coverage

[hahn-kev-bot]

---

AI-generated summary

Adds direct coverage for the CRDT correctness guarantees that previously had none — the second batch from the test-suite review.

Hybrid clock (HybridDateTimeProviderTests, new file). Every other test injects a MockTimeProvider that stubs out the real clock logic, so HybridDateTimeProvider had zero coverage. New tests use a settable TimeProvider to exercise:

• a forward wall clock resets the counter;
• a backward/equal wall clock reuses the newer timestamp and increments the counter (staying monotonic across repeated calls);
• TakeLatestTime advances local time past the newest received commit and ignores older ones.

HybridDateTime ordering (HybridDateTimeTests). Added the comparison operators (<, >, <=, >=) and the counter tie-break on equal instants, which drive the clock's counter-increment decision and were untested.

Sync convergence (SyncTests). Existing multi-client tests only edited different entities or the same entity with strictly-increasing timestamps, so the tie-break path never ran. Added:

• concurrent edits to the same entity at the same instant converge to one deterministic winner on both replicas;
• later-timestamp-wins for concurrent same-entity edits;
• SyncWith idempotency (a second sync transfers nothing);
• the ShouldSync/IsSynced short-circuit via NullSyncable (IsSynced was never asserted anywhere before).

Test-only; no production code changed.

Test plan

• dotnet test on the affected tests passes (23/23 locally, including pre-existing HybridDateTimeTests).

[coderabbitai]

Warning

Review limit reached

@hahn-kev, you've reached your PR review limit, so we couldn't start this review.

Next review available in: 56 minutes

You've used all free OSS reviews for now. Wait for the free limit to reset to keep reviewing this public repository.

How can I continue?

After more reviews become available, a review can be triggered using the @coderabbitai review command as a PR comment. Alternatively, push new commits to this PR.

To avoid repeated limits, reduce automatic review volume by pausing incremental auto-reviews earlier, using label-based review opt-in, excluding WIP or generated PR titles, or requesting reviews manually when the PR is ready. If your team needs uninterrupted high-volume reviews, an organization admin can enable usage-based reviews.

How do review limits work?

CodeRabbit enforces per-developer PR review limits for each organization. Most developers receive the normal plan review availability.

For paid Pro and Pro+ PR reviews, CodeRabbit uses adaptive limits for sustained high-volume activity. When a developer's recent PR review activity reaches the 95th percentile or higher among CodeRabbit users, additional reviews become available more gradually as earlier reviews age out of the rolling window.

Please refer docs for additional details.

Review details

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 9eebee24-9422-4b79-8885-44ab4f505c2d

📥 Commits

Reviewing files that changed from the base of the PR and between 03f609f and e698f73.

📒 Files selected for processing (3)

• src/SIL.Harmony.Tests/Core/HybridDateTimeProviderTests.cs
• src/SIL.Harmony.Tests/Core/HybridDateTimeTests.cs
• src/SIL.Harmony.Tests/SyncTests.cs

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[hahn-kev]

@coderabbitai review

[coderabbitai]

⚠️ Action not completed

Review rate limited.

Note: CodeRabbit is an incremental review system and does not re-review already reviewed commits. This command is applicable only when automatic reviews are paused.

[hahn-kev]

@coderabbitai review

[coderabbitai]

⚠️ Action not completed

Review rate limited.

Note: CodeRabbit is an incremental review system and does not re-review already reviewed commits. This command is applicable only when automatic reviews are paused.