Add FrozenChildObservationTests: live-vs-frozen observation contract#27
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Characterises why a non-live @model value silently fails to drive a SwiftUI view — the mechanism behind the "sub-view stuck at a child's birth state" symptom whose framework fix (optional/container same-id unanchored child) landed in #26. - A child read out of a live parent is itself live (context != nil, lifetime == .active) and tracks subsequent mutations — the normal read path never hands a frozen copy to a sub-view. - A frozen copy (same modelID, no context) does NOT participate in Apple's withObservationTracking (the iOS 17+ registrar path SwiftUI uses), so a view holding one never re-renders. Hence a non-live value must never reach an @ObservedModel. - Also covers reading per-instance identity via the public `modelID` (added in #26) when an explicit domain `id` shadows Identifiable.id. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
…bservation-tests # Conflicts: # CHANGELOG.md
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Summary
Follow-up to #26 (merged), which fixed the optional/container same-
idunanchored-child bug and exposedpublic var Model.modelID. This PR adds the regression/characterisation tests for the underlying observation contract — the why behind the "SwiftUI sub-view stuck at a child's birth state" field symptom. Tests only; no source changes.FrozenChildObservationTestspins down:context != nil,lifetime == .active) and tracks subsequent mutations — the normal read path never hands a frozen copy to a sub-view.modelID,context == nil) silently does not participate in Apple'swithObservationTracking— the iOS 17+ registrar path SwiftUI drives invalidation through — so a view holding one never re-renders. This is the precise mechanism that makes a non-live value render birth state forever, and the reason such a value must never reach an@ObservedModel.modelID(added in Fix unanchored optional/container child on same-id replace; expose modelID #26) distinguishes two distinct instances that reuse the same explicit domainid(whereIdentifiable.idalone cannot).Validation
scripts/test --filter SwiftModelTests.FrozenChildObservationTests— all 4 tests pass against currentmain(post-#26). No source changes, so no behavior risk.🤖 Generated with Claude Code