FA-42188 / Listener lifecycle / Member archive

Disposed invalidation observer retains dirty field names · case 03

Disposed invalidation observer retains dirty field names; the returned lifecycle plan violates the stated transition contract.

Member previewVariant 3 · 3 implementations · 8 checks per implementation

Case contract

Plan a listener invalidation accumulator. Dirty field names form an insertion-ordered set; repeated invalidation keeps first order. Exactly one microtask is requested while dirty and unscheduled. A flush atomically detaches the current fields, so dirt arriving during callbacks becomes a later batch. Full invalidation supersedes field names. Disposed observers drop both batches. 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: fields = list(dict.fromkeys(s['dirty']+([s['incoming']] if s['incoming'] is not None else []))); schedule = bool(s['dirty'] or s['incoming'] is not None or s['full']) and not s['scheduled'] and not s['disposed']; flush_fields = list(dict.fromkeys(s['dirty'])) if s['flush'] and not s['disposed'] and not s['full'] else []; next_batch = list(dict.fromkeys(s['during'])) if s['flush'] and not s['disposed'] else []; full = s['full'] and s['flush'] and not s['disposed']; version = s['version']+int(s['flush'] and bool(s['dirty'] or s['full']) and not s['disposed']); scheduled_after = bool(s['during']) if s['flush'] else s['scheduled']; stale = s['delivered']<s['version']; reentrant = s['flush'] and s['running']; retained = [] if s['disposed'] else list(dict.fromkeys(s['dirty']))

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	`{"fields": ["c", "a"], "flush_fields": [], "full": false, "next_batch": [], "reentrant": true, "retained": ["c", "a"], "schedule": false, "scheduled_after": true, "stale": false, "version": 0}`	`{"fields": ["c", "a"], "flush_fields": [], "full": false, "next_batch": [], "reentrant": true, "retained": [], "schedule": false, "scheduled_after": true, "stale": false, "version": 0}`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.