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Demand is consumed for callbacks that were never delivered · case 04

Demand is consumed for callbacks that were never delivered; the returned lifecycle plan violates the stated transition contract.

Member previewVariant 4 · 3 implementations · 8 checks per implementation

Case contract

Plan local observer demand credit, not a network queue. A positive request adds credit up to a configured cap; nonpositive requests are rejected without consuming credit. Unlimited mode bypasses credit checks but not cancellation. A delivery consumes one credit only if delivered; buffered callbacks count against pending capacity, not demand. Cancellation clears outstanding demand. For the request-batch projection only, -1 is an explicit unlimited sentinel and the normalized result is None, otherwise positive requests saturate at cap. Inputs are finite state snapshots, including transitional and stale states; output fields are the exact independent actions/metadata defined by the corrected expression table. Numeric fixture capacities and counts vary with N. Field definitions, each independently computed from the input snapshot: grant = min(s['cap'],s['credit']+max(0,s['request'])); invalid = s['request']<=0; allow = s['has_value'] and not s['cancel'] and (s['unlimited'] or s['credit']>0); consume = max(0,s['credit']-int(s['delivered'] and not s['unlimited'])); cancel_credit = None if -1 in s['requests'] else min(s['cap'],sum(max(0,x) for x in s['requests'])); buffer_space = max(0,s['capacity']-s['pending']); backpressured = s['has_value'] and not s['unlimited'] and s['credit']==0 and not s['cancel']; terminal_wait = s['complete'] and s['pending']>0 and not s['cancel']; request_upstream = max(0,s['request']) if not s['cancel'] and not s['complete'] else 0; saturation = s['credit']>=s['cap']

Why this case matters

Observer implementations need to preserve this state while subscriptions enter, execute, and leave their lifecycle.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
transition 0	`{"allow": false, "backpressured": false, "buffer_space": 0, "cancel_credit": null, "consume": 15, "grant": 8, "invalid": false, "request_upstream": 0, "saturation": true, "terminal_wait": false}`	`{"allow": false, "backpressured": false, "buffer_space": 0, "cancel_credit": null, "consume": 16, "grant": 8, "invalid": false, "request_upstream": 0, "saturation": true, "terminal_wait": false}`	Failed

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