FA-73940 / Feature flag rollout bucketing / Member archive

Prerequisite flag chain: Evaluation continues past an unmet prerequisite · case 05

The reported blocking prerequisite is the last failing one, and later broken references surface.

Member previewVariant 5 · 3 implementations · 8 checks per implementation

Case contract

flags maps key -> {on, off, serve, prereqs:[[key, required variation]]}. Missing flags yield [None, MISSING, key]; revisiting a flag on the current path yields [None, CYCLE, key] (checked before on/off). An off flag serves [off, OFF, None]. Prerequisites are evaluated in order; MISSING/CYCLE results propagate unchanged; the first prerequisite that is OFF or serves a different variation stops evaluation with [off, PREREQUISITE_FAILED, that prerequisite key]. A prerequisite that itself failed counts as serving its off variation. Otherwise [serve, ON, None].

Why this case matters

Prerequisite chains gate dependent features and must fail closed with an actionable reason.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
first unmet prerequisite stops evaluation	`["off", "PREREQUISITE_FAILED", "c"]`	`["off", "PREREQUISITE_FAILED", "b"]`	Failed

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