FA-34196 / Notification interfaces / Open access
Notification inbox reconnect recovery: connection-restored from offline-cached · case 01
The connection-restored event leaves a notification in live instead of reconciling.
ROOT CAUSE
Reconnection declares the cached inbox current before reconciliation.
THE FAILURE
Reconnection declares the cached inbox current before reconciliation.
Unsuccessful approach: Clearing the cache creates a needless empty inbox flash.
Case contract
Notification inbox reconnect recovery is a bounded visual-notification workflow with mutable policy state {'cached': ['old'], 'cursor': 8, 'preview': 'old', 'fresh': False}. Its default transition relation is {('live', 'connection-lost'): 'offline-cached', ('offline-cached', 'connection-restored'): 'reconciling', ('reconciling', 'snapshot-current'): 'live', ('reconciling', 'snapshot-failed'): 'offline-error', ('offline-error', 'retry-refresh'): 'reconciling', ('reconciling', 'connection-lost'): 'offline-cached', ('offline-cached', 'open-cached-item'): 'offline-preview', ('offline-preview', 'close-preview'): 'offline-cached', ('offline-preview', 'connection-restored'): 'reconciling-preview', ('reconciling-preview', 'snapshot-current'): 'live-preview'}; domain inputs can suppress or redirect transitions and update policy fields, as specified in solve. Different-generation events are inert. Batches apply in order. Optional observe returns the selected policy field alongside the phase.
Why this case matters
Visual notification lifecycle ordering can leave an inbox or toast showing the wrong actionable state even when transport succeeds.
1 / The failure
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(initial, events, generation, payload=None, observe=None):
table = {('live', 'connection-lost'): 'offline-cached', ('offline-cached', 'connection-restored'): 'live', ('reconciling', 'snapshot-current'): 'live', ('reconciling', 'snapshot-failed'): 'offline-error', ('offline-error', 'retry-refresh'): 'reconciling', ('reconciling', 'connection-lost'): 'offline-cached', ('offline-cached', 'open-cached-item'): 'offline-preview', ('offline-preview', 'close-preview'): 'offline-cached', ('offline-preview', 'connection-restored'): 'reconciling-preview', ('reconciling-preview', 'snapshot-current'): 'live-preview'}
data = json.loads(json.dumps({'cached': ['old'], 'cursor': 8, 'preview': 'old', 'fresh': False})) if payload is None else {**json.loads(json.dumps({'cached': ['old'], 'cursor': 8, 'preview': 'old', 'fresh': False})), **json.loads(json.dumps(payload))}
state = initial
for delivery in events:
event, event_generation = delivery[:2]
arg = delivery[2] if len(delivery) > 2 else {}
if event_generation == generation:
previous = state
if event == 'snapshot-current':
if arg.get('cursor',data['cursor']) < data['cursor']: event = 'unknown-event'
else:
data['cursor'] = arg.get('cursor',data['cursor'])
data['cached'] = arg.get('items',data['cached'])[:]
if event == 'connection-lost': data['fresh'] = False
state = table.get((state, event), state)
if state in ('live','live-preview'): data['fresh'] = True
if state == 'live-preview' and data['preview'] not in data['cached']: data['preview'] = None
if state == 'empty': data['cached'] = []
return {'phase': state, 'value': data[observe]} if observe else state
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('live / connection-lost', solve('live', [('connection-lost', N)], N), 'offline-cached')
check('offline-cached / connection-restored', solve('offline-cached', [('connection-restored', N)], N), 'reconciling')
check('reconciling / snapshot-current', solve('reconciling', [('snapshot-current', N)], N), 'live')
check('reconciling / snapshot-failed', solve('reconciling', [('snapshot-failed', N)], N), 'offline-error')
check('offline-error / retry-refresh', solve('offline-error', [('retry-refresh', N)], N), 'reconciling')
check('reconciling / connection-lost', solve('reconciling', [('connection-lost', N)], N), 'offline-cached')
check('offline-cached / open-cached-item', solve('offline-cached', [('open-cached-item', N)], N), 'offline-preview')
check('offline-preview / close-preview', solve('offline-preview', [('close-preview', N)], N), 'offline-cached')
check('offline-preview / connection-restored', solve('offline-preview', [('connection-restored', N)], N), 'reconciling-preview')
check('reconciling-preview / snapshot-current', solve('reconciling-preview', [('snapshot-current', N)], N), 'live-preview')
check('older notification incarnation', solve('live', [('connection-lost', N - 1)], N), 'live')
check('future notification incarnation', solve('live', [('connection-lost', N + 1)], N), 'live')
check('unknown event is inert', solve('live', [('unknown-event', N)], N), 'live')
check('empty delivery batch', solve('live', [], N), 'live')
check('N stale deliveries before current delivery', solve('live', [('connection-lost', N - 1)] * N + [('connection-lost', N)], N), 'offline-cached')
check('trace connection-lost then connection-restored', solve('live', [('connection-lost', N), ('connection-restored', N)], N), 'reconciling')
check('trace connection-lost then open-cached-item', solve('live', [('connection-lost', N), ('open-cached-item', N)], N), 'offline-preview')
check('trace connection-restored then snapshot-current', solve('offline-cached', [('connection-restored', N), ('snapshot-current', N)], N), 'live')
check('trace connection-restored then snapshot-failed', solve('offline-cached', [('connection-restored', N), ('snapshot-failed', N)], N), 'offline-error')
check('trace connection-restored then connection-lost', solve('offline-cached', [('connection-restored', N), ('connection-lost', N)], N), 'offline-cached')
check('trace snapshot-current then connection-lost', solve('reconciling', [('snapshot-current', N), ('connection-lost', N)], N), 'offline-cached')
check('trace snapshot-failed then retry-refresh', solve('reconciling', [('snapshot-failed', N), ('retry-refresh', N)], N), 'reconciling')
check('trace retry-refresh then snapshot-current', solve('offline-error', [('retry-refresh', N), ('snapshot-current', N)], N), 'live')
check('trace retry-refresh then snapshot-failed', solve('offline-error', [('retry-refresh', N), ('snapshot-failed', N)], N), 'offline-error')
check('trace retry-refresh then connection-lost', solve('offline-error', [('retry-refresh', N), ('connection-lost', N)], N), 'offline-cached')
check('trace connection-lost then connection-restored', solve('reconciling', [('connection-lost', N), ('connection-restored', N)], N), 'reconciling')
check('trace connection-lost then open-cached-item', solve('reconciling', [('connection-lost', N), ('open-cached-item', N)], N), 'offline-preview')
check('trace open-cached-item then close-preview', solve('offline-cached', [('open-cached-item', N), ('close-preview', N)], N), 'offline-cached')
check('trace open-cached-item then connection-restored', solve('offline-cached', [('open-cached-item', N), ('connection-restored', N)], N), 'reconciling-preview')
check('trace close-preview then connection-restored', solve('offline-preview', [('close-preview', N), ('connection-restored', N)], N), 'reconciling')
check('trace close-preview then open-cached-item', solve('offline-preview', [('close-preview', N), ('open-cached-item', N)], N), 'offline-preview')
check('trace connection-restored then snapshot-current', solve('offline-preview', [('connection-restored', N), ('snapshot-current', N)], N), 'live-preview')
check('domain state regression 1: cached', solve('reconciling', [('snapshot-current', N, {'cursor': 7, 'items': ['stale']})], N, {}, 'cached'), {'phase': 'reconciling', 'value': ['old']})
check('domain state regression 2: cached', solve('reconciling', [('snapshot-current', N, {'cursor': 9, 'items': ['new']})], N, {}, 'cached'), {'phase': 'live', 'value': ['new']})
check('domain state regression 3: cached', solve('live', [('connection-lost', N, {})], N, {'fresh': True}, 'cached'), {'phase': 'offline-cached', 'value': ['old']})
check('domain state regression 4: preview', solve('reconciling-preview', [('snapshot-current', N, {'items': ['new']})], N, {}, 'preview'), {'phase': 'live-preview', 'value': None})
check('domain state regression 5: preview', solve('reconciling-preview', [('snapshot-current', N, {'items': ['old', 'new']})], N, {}, 'preview'), {'phase': 'live-preview', 'value': 'old'})
check('domain state regression 6: fresh', solve('reconciling', [('snapshot-failed', N, {})], N, {}, 'fresh'), {'phase': 'offline-error', 'value': False})
check('domain state regression 7: preview', solve('offline-preview', [('connection-restored', N, {}), ('snapshot-current', N, {'cursor': 9, 'items': ['new']})], N, {}, 'preview'), {'phase': 'live-preview', 'value': None})
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| live / connection-lost | offline-cached | offline-cached | Passed |
| offline-cached / connection-restored | live | reconciling | Failed |
| reconciling / snapshot-current | live | live | Passed |
| reconciling / snapshot-failed | offline-error | offline-error | Passed |
| offline-error / retry-refresh | reconciling | reconciling | Passed |
| reconciling / connection-lost | offline-cached | offline-cached | Passed |
| offline-cached / open-cached-item | offline-preview | offline-preview | Passed |
| offline-preview / close-preview | offline-cached | offline-cached | Passed |
| offline-preview / connection-restored | reconciling-preview | reconciling-preview | Passed |
| reconciling-preview / snapshot-current | live-preview | live-preview | Passed |
| older notification incarnation | live | live | Passed |
| future notification incarnation | live | live | Passed |
| unknown event is inert | live | live | Passed |
| empty delivery batch | live | live | Passed |
| N stale deliveries before current delivery | offline-cached | offline-cached | Passed |
| trace connection-lost then connection-restored | live | reconciling | Failed |
| trace connection-lost then open-cached-item | offline-preview | offline-preview | Passed |
| trace connection-restored then snapshot-current | live | live | Passed |
| trace connection-restored then snapshot-failed | live | offline-error | Failed |
| trace connection-restored then connection-lost | offline-cached | offline-cached | Passed |
| trace snapshot-current then connection-lost | offline-cached | offline-cached | Passed |
| trace snapshot-failed then retry-refresh | reconciling | reconciling | Passed |
| trace retry-refresh then snapshot-current | live | live | Passed |
| trace retry-refresh then snapshot-failed | offline-error | offline-error | Passed |
| trace retry-refresh then connection-lost | offline-cached | offline-cached | Passed |
| trace connection-lost then connection-restored | live | reconciling | Failed |
| trace connection-lost then open-cached-item | offline-preview | offline-preview | Passed |
| trace open-cached-item then close-preview | offline-cached | offline-cached | Passed |
| trace open-cached-item then connection-restored | reconciling-preview | reconciling-preview | Passed |
| trace close-preview then connection-restored | live | reconciling | Failed |
| trace close-preview then open-cached-item | offline-preview | offline-preview | Passed |
| trace connection-restored then snapshot-current | live-preview | live-preview | Passed |
| domain state regression 1: cached | {'phase': 'reconciling', 'value': ['old']} | {'phase': 'reconciling', 'value': ['old']} | Passed |
| domain state regression 2: cached | {'phase': 'live', 'value': ['new']} | {'phase': 'live', 'value': ['new']} | Passed |
| domain state regression 3: cached | {'phase': 'offline-cached', 'value': ['old']} | {'phase': 'offline-cached', 'value': ['old']} | Passed |
| domain state regression 4: preview | {'phase': 'live-preview', 'value': None} | {'phase': 'live-preview', 'value': None} | Passed |
| domain state regression 5: preview | {'phase': 'live-preview', 'value': 'old'} | {'phase': 'live-preview', 'value': 'old'} | Passed |
| domain state regression 6: fresh | {'phase': 'offline-error', 'value': False} | {'phase': 'offline-error', 'value': False} | Passed |
| domain state regression 7: preview | {'phase': 'live-preview', 'value': None} | {'phase': 'live-preview', 'value': None} | Passed |
SHA-256 / bb49aa5c9d25af12a569a0255a826f075b3e5225b324414063632d71c771da47
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(initial, events, generation, payload=None, observe=None):
table = {('live', 'connection-lost'): 'offline-cached', ('offline-cached', 'connection-restored'): 'empty', ('reconciling', 'snapshot-current'): 'live', ('reconciling', 'snapshot-failed'): 'offline-error', ('offline-error', 'retry-refresh'): 'reconciling', ('reconciling', 'connection-lost'): 'offline-cached', ('offline-cached', 'open-cached-item'): 'offline-preview', ('offline-preview', 'close-preview'): 'offline-cached', ('offline-preview', 'connection-restored'): 'reconciling-preview', ('reconciling-preview', 'snapshot-current'): 'live-preview'}
data = json.loads(json.dumps({'cached': ['old'], 'cursor': 8, 'preview': 'old', 'fresh': False})) if payload is None else {**json.loads(json.dumps({'cached': ['old'], 'cursor': 8, 'preview': 'old', 'fresh': False})), **json.loads(json.dumps(payload))}
state = initial
for delivery in events:
event, event_generation = delivery[:2]
arg = delivery[2] if len(delivery) > 2 else {}
if event_generation == generation:
previous = state
if event == 'snapshot-current':
if arg.get('cursor',data['cursor']) < data['cursor']: event = 'unknown-event'
else:
data['cursor'] = arg.get('cursor',data['cursor'])
data['cached'] = arg.get('items',data['cached'])[:]
if event == 'connection-lost': data['fresh'] = False
state = table.get((state, event), state)
if state in ('live','live-preview'): data['fresh'] = True
if state == 'live-preview' and data['preview'] not in data['cached']: data['preview'] = None
if state == 'empty': data['cached'] = []
return {'phase': state, 'value': data[observe]} if observe else state
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('live / connection-lost', solve('live', [('connection-lost', N)], N), 'offline-cached')
check('offline-cached / connection-restored', solve('offline-cached', [('connection-restored', N)], N), 'reconciling')
check('reconciling / snapshot-current', solve('reconciling', [('snapshot-current', N)], N), 'live')
check('reconciling / snapshot-failed', solve('reconciling', [('snapshot-failed', N)], N), 'offline-error')
check('offline-error / retry-refresh', solve('offline-error', [('retry-refresh', N)], N), 'reconciling')
check('reconciling / connection-lost', solve('reconciling', [('connection-lost', N)], N), 'offline-cached')
check('offline-cached / open-cached-item', solve('offline-cached', [('open-cached-item', N)], N), 'offline-preview')
check('offline-preview / close-preview', solve('offline-preview', [('close-preview', N)], N), 'offline-cached')
check('offline-preview / connection-restored', solve('offline-preview', [('connection-restored', N)], N), 'reconciling-preview')
check('reconciling-preview / snapshot-current', solve('reconciling-preview', [('snapshot-current', N)], N), 'live-preview')
check('older notification incarnation', solve('live', [('connection-lost', N - 1)], N), 'live')
check('future notification incarnation', solve('live', [('connection-lost', N + 1)], N), 'live')
check('unknown event is inert', solve('live', [('unknown-event', N)], N), 'live')
check('empty delivery batch', solve('live', [], N), 'live')
check('N stale deliveries before current delivery', solve('live', [('connection-lost', N - 1)] * N + [('connection-lost', N)], N), 'offline-cached')
check('trace connection-lost then connection-restored', solve('live', [('connection-lost', N), ('connection-restored', N)], N), 'reconciling')
check('trace connection-lost then open-cached-item', solve('live', [('connection-lost', N), ('open-cached-item', N)], N), 'offline-preview')
check('trace connection-restored then snapshot-current', solve('offline-cached', [('connection-restored', N), ('snapshot-current', N)], N), 'live')
check('trace connection-restored then snapshot-failed', solve('offline-cached', [('connection-restored', N), ('snapshot-failed', N)], N), 'offline-error')
check('trace connection-restored then connection-lost', solve('offline-cached', [('connection-restored', N), ('connection-lost', N)], N), 'offline-cached')
check('trace snapshot-current then connection-lost', solve('reconciling', [('snapshot-current', N), ('connection-lost', N)], N), 'offline-cached')
check('trace snapshot-failed then retry-refresh', solve('reconciling', [('snapshot-failed', N), ('retry-refresh', N)], N), 'reconciling')
check('trace retry-refresh then snapshot-current', solve('offline-error', [('retry-refresh', N), ('snapshot-current', N)], N), 'live')
check('trace retry-refresh then snapshot-failed', solve('offline-error', [('retry-refresh', N), ('snapshot-failed', N)], N), 'offline-error')
check('trace retry-refresh then connection-lost', solve('offline-error', [('retry-refresh', N), ('connection-lost', N)], N), 'offline-cached')
check('trace connection-lost then connection-restored', solve('reconciling', [('connection-lost', N), ('connection-restored', N)], N), 'reconciling')
check('trace connection-lost then open-cached-item', solve('reconciling', [('connection-lost', N), ('open-cached-item', N)], N), 'offline-preview')
check('trace open-cached-item then close-preview', solve('offline-cached', [('open-cached-item', N), ('close-preview', N)], N), 'offline-cached')
check('trace open-cached-item then connection-restored', solve('offline-cached', [('open-cached-item', N), ('connection-restored', N)], N), 'reconciling-preview')
check('trace close-preview then connection-restored', solve('offline-preview', [('close-preview', N), ('connection-restored', N)], N), 'reconciling')
check('trace close-preview then open-cached-item', solve('offline-preview', [('close-preview', N), ('open-cached-item', N)], N), 'offline-preview')
check('trace connection-restored then snapshot-current', solve('offline-preview', [('connection-restored', N), ('snapshot-current', N)], N), 'live-preview')
check('domain state regression 1: cached', solve('reconciling', [('snapshot-current', N, {'cursor': 7, 'items': ['stale']})], N, {}, 'cached'), {'phase': 'reconciling', 'value': ['old']})
check('domain state regression 2: cached', solve('reconciling', [('snapshot-current', N, {'cursor': 9, 'items': ['new']})], N, {}, 'cached'), {'phase': 'live', 'value': ['new']})
check('domain state regression 3: cached', solve('live', [('connection-lost', N, {})], N, {'fresh': True}, 'cached'), {'phase': 'offline-cached', 'value': ['old']})
check('domain state regression 4: preview', solve('reconciling-preview', [('snapshot-current', N, {'items': ['new']})], N, {}, 'preview'), {'phase': 'live-preview', 'value': None})
check('domain state regression 5: preview', solve('reconciling-preview', [('snapshot-current', N, {'items': ['old', 'new']})], N, {}, 'preview'), {'phase': 'live-preview', 'value': 'old'})
check('domain state regression 6: fresh', solve('reconciling', [('snapshot-failed', N, {})], N, {}, 'fresh'), {'phase': 'offline-error', 'value': False})
check('domain state regression 7: preview', solve('offline-preview', [('connection-restored', N, {}), ('snapshot-current', N, {'cursor': 9, 'items': ['new']})], N, {}, 'preview'), {'phase': 'live-preview', 'value': None})
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| live / connection-lost | offline-cached | offline-cached | Passed |
| offline-cached / connection-restored | empty | reconciling | Failed |
| reconciling / snapshot-current | live | live | Passed |
| reconciling / snapshot-failed | offline-error | offline-error | Passed |
| offline-error / retry-refresh | reconciling | reconciling | Passed |
| reconciling / connection-lost | offline-cached | offline-cached | Passed |
| offline-cached / open-cached-item | offline-preview | offline-preview | Passed |
| offline-preview / close-preview | offline-cached | offline-cached | Passed |
| offline-preview / connection-restored | reconciling-preview | reconciling-preview | Passed |
| reconciling-preview / snapshot-current | live-preview | live-preview | Passed |
| older notification incarnation | live | live | Passed |
| future notification incarnation | live | live | Passed |
| unknown event is inert | live | live | Passed |
| empty delivery batch | live | live | Passed |
| N stale deliveries before current delivery | offline-cached | offline-cached | Passed |
| trace connection-lost then connection-restored | empty | reconciling | Failed |
| trace connection-lost then open-cached-item | offline-preview | offline-preview | Passed |
| trace connection-restored then snapshot-current | empty | live | Failed |
| trace connection-restored then snapshot-failed | empty | offline-error | Failed |
| trace connection-restored then connection-lost | empty | offline-cached | Failed |
| trace snapshot-current then connection-lost | offline-cached | offline-cached | Passed |
| trace snapshot-failed then retry-refresh | reconciling | reconciling | Passed |
| trace retry-refresh then snapshot-current | live | live | Passed |
| trace retry-refresh then snapshot-failed | offline-error | offline-error | Passed |
| trace retry-refresh then connection-lost | offline-cached | offline-cached | Passed |
| trace connection-lost then connection-restored | empty | reconciling | Failed |
| trace connection-lost then open-cached-item | offline-preview | offline-preview | Passed |
| trace open-cached-item then close-preview | offline-cached | offline-cached | Passed |
| trace open-cached-item then connection-restored | reconciling-preview | reconciling-preview | Passed |
| trace close-preview then connection-restored | empty | reconciling | Failed |
| trace close-preview then open-cached-item | offline-preview | offline-preview | Passed |
| trace connection-restored then snapshot-current | live-preview | live-preview | Passed |
| domain state regression 1: cached | {'phase': 'reconciling', 'value': ['old']} | {'phase': 'reconciling', 'value': ['old']} | Passed |
| domain state regression 2: cached | {'phase': 'live', 'value': ['new']} | {'phase': 'live', 'value': ['new']} | Passed |
| domain state regression 3: cached | {'phase': 'offline-cached', 'value': ['old']} | {'phase': 'offline-cached', 'value': ['old']} | Passed |
| domain state regression 4: preview | {'phase': 'live-preview', 'value': None} | {'phase': 'live-preview', 'value': None} | Passed |
| domain state regression 5: preview | {'phase': 'live-preview', 'value': 'old'} | {'phase': 'live-preview', 'value': 'old'} | Passed |
| domain state regression 6: fresh | {'phase': 'offline-error', 'value': False} | {'phase': 'offline-error', 'value': False} | Passed |
| domain state regression 7: preview | {'phase': 'live-preview', 'value': None} | {'phase': 'live-preview', 'value': None} | Passed |
SHA-256 / e53f779fc6268cd6a269d8d1706ba53018cb9e3f522e0ac536a659fb953dd1fb
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This mechanism has 39 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.
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Sign in to the archive ↗Verification & scope
Stipulated single-notification state and policy model only. Event delivery and acknowledgements are explicit test inputs. No DOM, accessibility announcements, live timers, networking, actual rendering, or production-platform conformance is simulated. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.
Observations recorded using Python 3.12.14 at 2026-09-29T14:42:29.909175+00:00.
Case digest / 97150051bc999ba2abb02a2cf1e097bc417003d510a9032cfe9c42805a157804