FA-4740 / Scoped mappings / Member archive

Chainmap parents drops exactly one scope · case 05

The operation returns a result or retained state that violates this contract: The parents view removes only the current first scope and retains remaining scope boundaries; an empty parent chain exposes one empty map.

Member previewVariant 5 · 3 implementations · 4 checks per implementation

Case scope

A controlled failure with recorded boundary checks.

Why this case matters

A controlled local-runtime regression for collection APIs, language semantics, or ownership wrappers. Fixtures include boundary and interaction cases.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
two scopes	`[{"a": 1}, {"a": 2}]`	`[{"a": 2}]`	Failed

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