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FA-34701 / Notification interfaces / Open access

Notification channel preference feedback: save-failure from disable-pending · case 01

The save-failure event leaves a notification in disabled instead of disable-error.

Verified by executionVariant 1 · 39 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Failed disable still promises no future notifications.

THE FAILURE

Failed disable still promises no future notifications.

Unsuccessful approach: Silent rollback hides why the user's preference did not stick.

Case contract

Notification channel preference feedback is a bounded visual-notification workflow with mutable policy state {'channel': 'mentions', 'channels': {'mentions': True, 'security': True}, 'request': 2, 'desired': True}. Its default transition relation is {('enabled', 'disable-toggle'): 'disable-pending', ('disable-pending', 'save-success'): 'disabled', ('disable-pending', 'save-failure'): 'disable-error', ('disabled', 'enable-toggle'): 'enable-pending', ('enable-pending', 'save-success'): 'enabled', ('enable-pending', 'save-failure'): 'enable-error', ('disable-error', 'retry-disable'): 'disable-pending', ('enable-error', 'retry-enable'): 'enable-pending', ('disable-pending', 'toggle-back-on'): 'cancel-disable-pending', ('cancel-disable-pending', 'disable-save-completes'): 'enable-pending'}; 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 = {('enabled', 'disable-toggle'): 'disable-pending', ('disable-pending', 'save-success'): 'disabled', ('disable-pending', 'save-failure'): 'disabled', ('disabled', 'enable-toggle'): 'enable-pending', ('enable-pending', 'save-success'): 'enabled', ('enable-pending', 'save-failure'): 'enable-error', ('disable-error', 'retry-disable'): 'disable-pending', ('enable-error', 'retry-enable'): 'enable-pending', ('disable-pending', 'toggle-back-on'): 'cancel-disable-pending', ('cancel-disable-pending', 'disable-save-completes'): 'enable-pending'}
    data = json.loads(json.dumps({'channel': 'mentions', 'channels': {'mentions': True, 'security': True}, 'request': 2, 'desired': True})) if payload is None else {**json.loads(json.dumps({'channel': 'mentions', 'channels': {'mentions': True, 'security': True}, 'request': 2, 'desired': True})), **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.startswith('save-') and arg.get('request',data['request']) != data['request']: event = 'unknown-event'
            if event in ('disable-toggle','retry-disable'): data['desired'] = False
            if event in ('enable-toggle','retry-enable','toggle-back-on'): data['desired'] = True
            state = table.get((state, event), state)
            if state == 'disabled': data['channels'][data['channel']] = False
            if state == 'enabled': data['channels'][data['channel']] = True
            if state == 'enable-pending' and previous == 'cancel-disable-pending': data['request'] += 1
    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('enabled / disable-toggle', solve('enabled', [('disable-toggle', N)], N), 'disable-pending')
check('disable-pending / save-success', solve('disable-pending', [('save-success', N)], N), 'disabled')
check('disable-pending / save-failure', solve('disable-pending', [('save-failure', N)], N), 'disable-error')
check('disabled / enable-toggle', solve('disabled', [('enable-toggle', N)], N), 'enable-pending')
check('enable-pending / save-success', solve('enable-pending', [('save-success', N)], N), 'enabled')
check('enable-pending / save-failure', solve('enable-pending', [('save-failure', N)], N), 'enable-error')
check('disable-error / retry-disable', solve('disable-error', [('retry-disable', N)], N), 'disable-pending')
check('enable-error / retry-enable', solve('enable-error', [('retry-enable', N)], N), 'enable-pending')
check('disable-pending / toggle-back-on', solve('disable-pending', [('toggle-back-on', N)], N), 'cancel-disable-pending')
check('cancel-disable-pending / disable-save-completes', solve('cancel-disable-pending', [('disable-save-completes', N)], N), 'enable-pending')
check('older notification incarnation', solve('enabled', [('disable-toggle', N - 1)], N), 'enabled')
check('future notification incarnation', solve('enabled', [('disable-toggle', N + 1)], N), 'enabled')
check('unknown event is inert', solve('enabled', [('unknown-event', N)], N), 'enabled')
check('empty delivery batch', solve('enabled', [], N), 'enabled')
check('N stale deliveries before current delivery', solve('enabled', [('disable-toggle', N - 1)] * N + [('disable-toggle', N)], N), 'disable-pending')
check('trace disable-toggle then save-success', solve('enabled', [('disable-toggle', N), ('save-success', N)], N), 'disabled')
check('trace disable-toggle then save-failure', solve('enabled', [('disable-toggle', N), ('save-failure', N)], N), 'disable-error')
check('trace disable-toggle then toggle-back-on', solve('enabled', [('disable-toggle', N), ('toggle-back-on', N)], N), 'cancel-disable-pending')
check('trace save-success then enable-toggle', solve('disable-pending', [('save-success', N), ('enable-toggle', N)], N), 'enable-pending')
check('trace save-failure then retry-disable', solve('disable-pending', [('save-failure', N), ('retry-disable', N)], N), 'disable-pending')
check('trace enable-toggle then save-success', solve('disabled', [('enable-toggle', N), ('save-success', N)], N), 'enabled')
check('trace enable-toggle then save-failure', solve('disabled', [('enable-toggle', N), ('save-failure', N)], N), 'enable-error')
check('trace save-success then disable-toggle', solve('enable-pending', [('save-success', N), ('disable-toggle', N)], N), 'disable-pending')
check('trace save-failure then retry-enable', solve('enable-pending', [('save-failure', N), ('retry-enable', N)], N), 'enable-pending')
check('trace retry-disable then save-success', solve('disable-error', [('retry-disable', N), ('save-success', N)], N), 'disabled')
check('trace retry-disable then save-failure', solve('disable-error', [('retry-disable', N), ('save-failure', N)], N), 'disable-error')
check('trace retry-disable then toggle-back-on', solve('disable-error', [('retry-disable', N), ('toggle-back-on', N)], N), 'cancel-disable-pending')
check('trace retry-enable then save-success', solve('enable-error', [('retry-enable', N), ('save-success', N)], N), 'enabled')
check('trace retry-enable then save-failure', solve('enable-error', [('retry-enable', N), ('save-failure', N)], N), 'enable-error')
check('trace toggle-back-on then disable-save-completes', solve('disable-pending', [('toggle-back-on', N), ('disable-save-completes', N)], N), 'enable-pending')
check('trace disable-save-completes then save-success', solve('cancel-disable-pending', [('disable-save-completes', N), ('save-success', N)], N), 'enabled')
check('trace disable-save-completes then save-failure', solve('cancel-disable-pending', [('disable-save-completes', N), ('save-failure', N)], N), 'enable-error')
check('domain state regression 1: channels', solve('disable-pending', [('save-success', N, {'request': 1})], N, {}, 'channels'), {'phase': 'disable-pending', 'value': {'mentions': True, 'security': True}})
check('domain state regression 2: channels', solve('disable-pending', [('save-success', N, {})], N, {}, 'channels'), {'phase': 'disabled', 'value': {'mentions': False, 'security': True}})
check('domain state regression 3: channels', solve('disable-pending', [('save-failure', N, {})], N, {}, 'channels'), {'phase': 'disable-error', 'value': {'mentions': True, 'security': True}})
check('domain state regression 4: desired', solve('disabled', [('enable-toggle', N, {})], N, {'channels': {'mentions': False, 'security': True}}, 'desired'), {'phase': 'enable-pending', 'value': True})
check('domain state regression 5: desired', solve('disable-pending', [('toggle-back-on', N, {})], N, {'desired': False}, 'desired'), {'phase': 'cancel-disable-pending', 'value': True})
check('domain state regression 6: request', solve('cancel-disable-pending', [('disable-save-completes', N, {})], N, {}, 'request'), {'phase': 'enable-pending', 'value': 3})
check('domain state regression 7: channels', solve('enabled', [('disable-toggle', N, {}), ('toggle-back-on', N, {}), ('disable-save-completes', N, {}), ('save-success', N, {'request': 3})], N, {}, 'channels'), {'phase': 'enabled', 'value': {'mentions': True, 'security': True}})
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 fixtureActualExpectedOutcome
enabled / disable-toggledisable-pendingdisable-pendingPassed
disable-pending / save-successdisableddisabledPassed
disable-pending / save-failuredisableddisable-errorFailed
disabled / enable-toggleenable-pendingenable-pendingPassed
enable-pending / save-successenabledenabledPassed
enable-pending / save-failureenable-errorenable-errorPassed
disable-error / retry-disabledisable-pendingdisable-pendingPassed
enable-error / retry-enableenable-pendingenable-pendingPassed
disable-pending / toggle-back-oncancel-disable-pendingcancel-disable-pendingPassed
cancel-disable-pending / disable-save-completesenable-pendingenable-pendingPassed
older notification incarnationenabledenabledPassed
future notification incarnationenabledenabledPassed
unknown event is inertenabledenabledPassed
empty delivery batchenabledenabledPassed
N stale deliveries before current deliverydisable-pendingdisable-pendingPassed
trace disable-toggle then save-successdisableddisabledPassed
trace disable-toggle then save-failuredisableddisable-errorFailed
trace disable-toggle then toggle-back-oncancel-disable-pendingcancel-disable-pendingPassed
trace save-success then enable-toggleenable-pendingenable-pendingPassed
trace save-failure then retry-disabledisableddisable-pendingFailed
trace enable-toggle then save-successenabledenabledPassed
trace enable-toggle then save-failureenable-errorenable-errorPassed
trace save-success then disable-toggledisable-pendingdisable-pendingPassed
trace save-failure then retry-enableenable-pendingenable-pendingPassed
trace retry-disable then save-successdisableddisabledPassed
trace retry-disable then save-failuredisableddisable-errorFailed
trace retry-disable then toggle-back-oncancel-disable-pendingcancel-disable-pendingPassed
trace retry-enable then save-successenabledenabledPassed
trace retry-enable then save-failureenable-errorenable-errorPassed
trace toggle-back-on then disable-save-completesenable-pendingenable-pendingPassed
trace disable-save-completes then save-successenabledenabledPassed
trace disable-save-completes then save-failureenable-errorenable-errorPassed
domain state regression 1: channels{'phase': 'disable-pending', 'value': {'mentions': True, 'security': True}}{'phase': 'disable-pending', 'value': {'mentions': True, 'security': True}}Passed
domain state regression 2: channels{'phase': 'disabled', 'value': {'mentions': False, 'security': True}}{'phase': 'disabled', 'value': {'mentions': False, 'security': True}}Passed
domain state regression 3: channels{'phase': 'disabled', 'value': {'mentions': False, 'security': True}}{'phase': 'disable-error', 'value': {'mentions': True, 'security': True}}Failed
domain state regression 4: desired{'phase': 'enable-pending', 'value': True}{'phase': 'enable-pending', 'value': True}Passed
domain state regression 5: desired{'phase': 'cancel-disable-pending', 'value': True}{'phase': 'cancel-disable-pending', 'value': True}Passed
domain state regression 6: request{'phase': 'enable-pending', 'value': 3}{'phase': 'enable-pending', 'value': 3}Passed
domain state regression 7: channels{'phase': 'enabled', 'value': {'mentions': True, 'security': True}}{'phase': 'enabled', 'value': {'mentions': True, 'security': True}}Passed

SHA-256 / bab106001025c34c2a37952a67b4988ed1718daa7ad70da9643f6cb4a4729112

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 = {('enabled', 'disable-toggle'): 'disable-pending', ('disable-pending', 'save-success'): 'disabled', ('disable-pending', 'save-failure'): 'enabled', ('disabled', 'enable-toggle'): 'enable-pending', ('enable-pending', 'save-success'): 'enabled', ('enable-pending', 'save-failure'): 'enable-error', ('disable-error', 'retry-disable'): 'disable-pending', ('enable-error', 'retry-enable'): 'enable-pending', ('disable-pending', 'toggle-back-on'): 'cancel-disable-pending', ('cancel-disable-pending', 'disable-save-completes'): 'enable-pending'}
    data = json.loads(json.dumps({'channel': 'mentions', 'channels': {'mentions': True, 'security': True}, 'request': 2, 'desired': True})) if payload is None else {**json.loads(json.dumps({'channel': 'mentions', 'channels': {'mentions': True, 'security': True}, 'request': 2, 'desired': True})), **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.startswith('save-') and arg.get('request',data['request']) != data['request']: event = 'unknown-event'
            if event in ('disable-toggle','retry-disable'): data['desired'] = False
            if event in ('enable-toggle','retry-enable','toggle-back-on'): data['desired'] = True
            state = table.get((state, event), state)
            if state == 'disabled': data['channels'][data['channel']] = False
            if state == 'enabled': data['channels'][data['channel']] = True
            if state == 'enable-pending' and previous == 'cancel-disable-pending': data['request'] += 1
    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('enabled / disable-toggle', solve('enabled', [('disable-toggle', N)], N), 'disable-pending')
check('disable-pending / save-success', solve('disable-pending', [('save-success', N)], N), 'disabled')
check('disable-pending / save-failure', solve('disable-pending', [('save-failure', N)], N), 'disable-error')
check('disabled / enable-toggle', solve('disabled', [('enable-toggle', N)], N), 'enable-pending')
check('enable-pending / save-success', solve('enable-pending', [('save-success', N)], N), 'enabled')
check('enable-pending / save-failure', solve('enable-pending', [('save-failure', N)], N), 'enable-error')
check('disable-error / retry-disable', solve('disable-error', [('retry-disable', N)], N), 'disable-pending')
check('enable-error / retry-enable', solve('enable-error', [('retry-enable', N)], N), 'enable-pending')
check('disable-pending / toggle-back-on', solve('disable-pending', [('toggle-back-on', N)], N), 'cancel-disable-pending')
check('cancel-disable-pending / disable-save-completes', solve('cancel-disable-pending', [('disable-save-completes', N)], N), 'enable-pending')
check('older notification incarnation', solve('enabled', [('disable-toggle', N - 1)], N), 'enabled')
check('future notification incarnation', solve('enabled', [('disable-toggle', N + 1)], N), 'enabled')
check('unknown event is inert', solve('enabled', [('unknown-event', N)], N), 'enabled')
check('empty delivery batch', solve('enabled', [], N), 'enabled')
check('N stale deliveries before current delivery', solve('enabled', [('disable-toggle', N - 1)] * N + [('disable-toggle', N)], N), 'disable-pending')
check('trace disable-toggle then save-success', solve('enabled', [('disable-toggle', N), ('save-success', N)], N), 'disabled')
check('trace disable-toggle then save-failure', solve('enabled', [('disable-toggle', N), ('save-failure', N)], N), 'disable-error')
check('trace disable-toggle then toggle-back-on', solve('enabled', [('disable-toggle', N), ('toggle-back-on', N)], N), 'cancel-disable-pending')
check('trace save-success then enable-toggle', solve('disable-pending', [('save-success', N), ('enable-toggle', N)], N), 'enable-pending')
check('trace save-failure then retry-disable', solve('disable-pending', [('save-failure', N), ('retry-disable', N)], N), 'disable-pending')
check('trace enable-toggle then save-success', solve('disabled', [('enable-toggle', N), ('save-success', N)], N), 'enabled')
check('trace enable-toggle then save-failure', solve('disabled', [('enable-toggle', N), ('save-failure', N)], N), 'enable-error')
check('trace save-success then disable-toggle', solve('enable-pending', [('save-success', N), ('disable-toggle', N)], N), 'disable-pending')
check('trace save-failure then retry-enable', solve('enable-pending', [('save-failure', N), ('retry-enable', N)], N), 'enable-pending')
check('trace retry-disable then save-success', solve('disable-error', [('retry-disable', N), ('save-success', N)], N), 'disabled')
check('trace retry-disable then save-failure', solve('disable-error', [('retry-disable', N), ('save-failure', N)], N), 'disable-error')
check('trace retry-disable then toggle-back-on', solve('disable-error', [('retry-disable', N), ('toggle-back-on', N)], N), 'cancel-disable-pending')
check('trace retry-enable then save-success', solve('enable-error', [('retry-enable', N), ('save-success', N)], N), 'enabled')
check('trace retry-enable then save-failure', solve('enable-error', [('retry-enable', N), ('save-failure', N)], N), 'enable-error')
check('trace toggle-back-on then disable-save-completes', solve('disable-pending', [('toggle-back-on', N), ('disable-save-completes', N)], N), 'enable-pending')
check('trace disable-save-completes then save-success', solve('cancel-disable-pending', [('disable-save-completes', N), ('save-success', N)], N), 'enabled')
check('trace disable-save-completes then save-failure', solve('cancel-disable-pending', [('disable-save-completes', N), ('save-failure', N)], N), 'enable-error')
check('domain state regression 1: channels', solve('disable-pending', [('save-success', N, {'request': 1})], N, {}, 'channels'), {'phase': 'disable-pending', 'value': {'mentions': True, 'security': True}})
check('domain state regression 2: channels', solve('disable-pending', [('save-success', N, {})], N, {}, 'channels'), {'phase': 'disabled', 'value': {'mentions': False, 'security': True}})
check('domain state regression 3: channels', solve('disable-pending', [('save-failure', N, {})], N, {}, 'channels'), {'phase': 'disable-error', 'value': {'mentions': True, 'security': True}})
check('domain state regression 4: desired', solve('disabled', [('enable-toggle', N, {})], N, {'channels': {'mentions': False, 'security': True}}, 'desired'), {'phase': 'enable-pending', 'value': True})
check('domain state regression 5: desired', solve('disable-pending', [('toggle-back-on', N, {})], N, {'desired': False}, 'desired'), {'phase': 'cancel-disable-pending', 'value': True})
check('domain state regression 6: request', solve('cancel-disable-pending', [('disable-save-completes', N, {})], N, {}, 'request'), {'phase': 'enable-pending', 'value': 3})
check('domain state regression 7: channels', solve('enabled', [('disable-toggle', N, {}), ('toggle-back-on', N, {}), ('disable-save-completes', N, {}), ('save-success', N, {'request': 3})], N, {}, 'channels'), {'phase': 'enabled', 'value': {'mentions': True, 'security': True}})
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 fixtureActualExpectedOutcome
enabled / disable-toggledisable-pendingdisable-pendingPassed
disable-pending / save-successdisableddisabledPassed
disable-pending / save-failureenableddisable-errorFailed
disabled / enable-toggleenable-pendingenable-pendingPassed
enable-pending / save-successenabledenabledPassed
enable-pending / save-failureenable-errorenable-errorPassed
disable-error / retry-disabledisable-pendingdisable-pendingPassed
enable-error / retry-enableenable-pendingenable-pendingPassed
disable-pending / toggle-back-oncancel-disable-pendingcancel-disable-pendingPassed
cancel-disable-pending / disable-save-completesenable-pendingenable-pendingPassed
older notification incarnationenabledenabledPassed
future notification incarnationenabledenabledPassed
unknown event is inertenabledenabledPassed
empty delivery batchenabledenabledPassed
N stale deliveries before current deliverydisable-pendingdisable-pendingPassed
trace disable-toggle then save-successdisableddisabledPassed
trace disable-toggle then save-failureenableddisable-errorFailed
trace disable-toggle then toggle-back-oncancel-disable-pendingcancel-disable-pendingPassed
trace save-success then enable-toggleenable-pendingenable-pendingPassed
trace save-failure then retry-disableenableddisable-pendingFailed
trace enable-toggle then save-successenabledenabledPassed
trace enable-toggle then save-failureenable-errorenable-errorPassed
trace save-success then disable-toggledisable-pendingdisable-pendingPassed
trace save-failure then retry-enableenable-pendingenable-pendingPassed
trace retry-disable then save-successdisableddisabledPassed
trace retry-disable then save-failureenableddisable-errorFailed
trace retry-disable then toggle-back-oncancel-disable-pendingcancel-disable-pendingPassed
trace retry-enable then save-successenabledenabledPassed
trace retry-enable then save-failureenable-errorenable-errorPassed
trace toggle-back-on then disable-save-completesenable-pendingenable-pendingPassed
trace disable-save-completes then save-successenabledenabledPassed
trace disable-save-completes then save-failureenable-errorenable-errorPassed
domain state regression 1: channels{'phase': 'disable-pending', 'value': {'mentions': True, 'security': True}}{'phase': 'disable-pending', 'value': {'mentions': True, 'security': True}}Passed
domain state regression 2: channels{'phase': 'disabled', 'value': {'mentions': False, 'security': True}}{'phase': 'disabled', 'value': {'mentions': False, 'security': True}}Passed
domain state regression 3: channels{'phase': 'enabled', 'value': {'mentions': True, 'security': True}}{'phase': 'disable-error', 'value': {'mentions': True, 'security': True}}Failed
domain state regression 4: desired{'phase': 'enable-pending', 'value': True}{'phase': 'enable-pending', 'value': True}Passed
domain state regression 5: desired{'phase': 'cancel-disable-pending', 'value': True}{'phase': 'cancel-disable-pending', 'value': True}Passed
domain state regression 6: request{'phase': 'enable-pending', 'value': 3}{'phase': 'enable-pending', 'value': 3}Passed
domain state regression 7: channels{'phase': 'enabled', 'value': {'mentions': True, 'security': True}}{'phase': 'enabled', 'value': {'mentions': True, 'security': True}}Passed

SHA-256 / a9d78ab15c65200e21e456531e6fc158856733b0cc427b6a7289102b37ebb18c

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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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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 2026-09-29T14:42:34.821563+00:00.

Case digest / 41a8623acc78fd1876fdbb25da22b497f822eed621c3dea71ff639fee8bf2282