Task 11. Companion to Task 10, covering the intents held by
SiteReplicationActorTests and SfBufferResyncPredicateTests.
N1 Critical is re-expressed, not ported literally (D2). SfBufferResyncPredicate
existed because ReplaceAllAsync was a destructive DELETE-then-INSERT, so a
wrong-direction resync wiped a live buffer and the code needed an oldest-Up
predicate to decide authority. LocalDb's snapshot resync merges per row under
LWW and never deletes, so this asserts the property the guard protected — no
node loses rows to a peer's snapshot — with no directional-authority assertion,
because there is no active/standby asymmetry left to enforce. The setup is the
wipe scenario made concrete: each node writes rows the other never sees while
partitioned, plus a contended row, then they resync.
DEVIATION on the zero-fetch assertion. The plan asked for a fetcher test double
recording zero invocations; this harness has no actor system, no central and no
IDeploymentConfigFetcher in the graph, so the double would record zero calls
whether or not the fetch path still existed. An assertion that cannot fail is
worse than none, so the test proves the positive half — config reaches B over
replication alone — and the file records that the negative half is proved by
Task 15 deleting the code and the build still passing. It also records the D1
scope note: SiteReconciliationActor survives and legitimately fetches at
startup, so 'the standby never fetches, ever' would be false.
Non-vacuity verified by unregistering deployed_configurations: all 4 fail.
Claude-Session: https://claude.ai/code/session_01BL2Vu1ESDQ9SCN4gVKkdts
Joseph Doherty