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FA-34496 / Notification interfaces / Open access

Swipe-to-dismiss notification feedback: below-threshold-release from dragging · case 01

The below-threshold-release event leaves a notification in dismissed instead of returning.

Verified by executionVariant 1 · 37 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

A short drag is treated as a completed dismissal.

THE FAILURE

A short drag is treated as a completed dismissal.

Unsuccessful approach: Committing the short drag still violates the distance contract.

Case contract

Swipe-to-dismiss notification feedback is a bounded visual-notification workflow with mutable policy state {'offset': 0, 'threshold': 40, 'pointer': 7, 'removed': False}. Its default transition relation is {('resting', 'drag-start'): 'dragging', ('dragging', 'below-threshold-release'): 'returning', ('dragging', 'above-threshold-release'): 'committing', ('returning', 'snapback-finished'): 'resting', ('committing', 'dismiss-accepted'): 'exit-animating', ('committing', 'dismiss-rejected'): 'returning', ('exit-animating', 'animation-finished'): 'dismissed', ('dragging', 'pointer-cancel'): 'returning', ('exit-animating', 'reduced-motion-enabled'): 'dismissed', ('committing', 'second-pointer-down'): 'committing'}; 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 = {('resting', 'drag-start'): 'dragging', ('dragging', 'below-threshold-release'): 'dismissed', ('dragging', 'above-threshold-release'): 'committing', ('returning', 'snapback-finished'): 'resting', ('committing', 'dismiss-accepted'): 'exit-animating', ('committing', 'dismiss-rejected'): 'returning', ('exit-animating', 'animation-finished'): 'dismissed', ('dragging', 'pointer-cancel'): 'returning', ('exit-animating', 'reduced-motion-enabled'): 'dismissed', ('committing', 'second-pointer-down'): 'committing'}
    data = json.loads(json.dumps({'offset': 0, 'threshold': 40, 'pointer': 7, 'removed': False})) if payload is None else {**json.loads(json.dumps({'offset': 0, 'threshold': 40, 'pointer': 7, 'removed': 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 in ('below-threshold-release','above-threshold-release','pointer-cancel') and arg.get('pointer',data['pointer']) != data['pointer']: event = 'unknown-event'
            if event in ('below-threshold-release','above-threshold-release') and 'offset' in arg:
                data['offset'] = arg['offset']
                event = 'above-threshold-release' if abs(data['offset']) >= data['threshold'] else 'below-threshold-release'
            state = table.get((state, event), state)
            if state == 'resting': data['offset'] = 0
            if state == 'dismissed': data['removed'] = True
    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('resting / drag-start', solve('resting', [('drag-start', N)], N), 'dragging')
check('dragging / below-threshold-release', solve('dragging', [('below-threshold-release', N)], N), 'returning')
check('dragging / above-threshold-release', solve('dragging', [('above-threshold-release', N)], N), 'committing')
check('returning / snapback-finished', solve('returning', [('snapback-finished', N)], N), 'resting')
check('committing / dismiss-accepted', solve('committing', [('dismiss-accepted', N)], N), 'exit-animating')
check('committing / dismiss-rejected', solve('committing', [('dismiss-rejected', N)], N), 'returning')
check('exit-animating / animation-finished', solve('exit-animating', [('animation-finished', N)], N), 'dismissed')
check('dragging / pointer-cancel', solve('dragging', [('pointer-cancel', N)], N), 'returning')
check('exit-animating / reduced-motion-enabled', solve('exit-animating', [('reduced-motion-enabled', N)], N), 'dismissed')
check('committing / second-pointer-down', solve('committing', [('second-pointer-down', N)], N), 'committing')
check('older notification incarnation', solve('resting', [('drag-start', N - 1)], N), 'resting')
check('future notification incarnation', solve('resting', [('drag-start', N + 1)], N), 'resting')
check('unknown event is inert', solve('resting', [('unknown-event', N)], N), 'resting')
check('empty delivery batch', solve('resting', [], N), 'resting')
check('N stale deliveries before current delivery', solve('resting', [('drag-start', N - 1)] * N + [('drag-start', N)], N), 'dragging')
check('trace drag-start then below-threshold-release', solve('resting', [('drag-start', N), ('below-threshold-release', N)], N), 'returning')
check('trace drag-start then above-threshold-release', solve('resting', [('drag-start', N), ('above-threshold-release', N)], N), 'committing')
check('trace drag-start then pointer-cancel', solve('resting', [('drag-start', N), ('pointer-cancel', N)], N), 'returning')
check('trace below-threshold-release then snapback-finished', solve('dragging', [('below-threshold-release', N), ('snapback-finished', N)], N), 'resting')
check('trace above-threshold-release then dismiss-accepted', solve('dragging', [('above-threshold-release', N), ('dismiss-accepted', N)], N), 'exit-animating')
check('trace above-threshold-release then dismiss-rejected', solve('dragging', [('above-threshold-release', N), ('dismiss-rejected', N)], N), 'returning')
check('trace above-threshold-release then second-pointer-down', solve('dragging', [('above-threshold-release', N), ('second-pointer-down', N)], N), 'committing')
check('trace snapback-finished then drag-start', solve('returning', [('snapback-finished', N), ('drag-start', N)], N), 'dragging')
check('trace dismiss-accepted then animation-finished', solve('committing', [('dismiss-accepted', N), ('animation-finished', N)], N), 'dismissed')
check('trace dismiss-accepted then reduced-motion-enabled', solve('committing', [('dismiss-accepted', N), ('reduced-motion-enabled', N)], N), 'dismissed')
check('trace dismiss-rejected then snapback-finished', solve('committing', [('dismiss-rejected', N), ('snapback-finished', N)], N), 'resting')
check('trace pointer-cancel then snapback-finished', solve('dragging', [('pointer-cancel', N), ('snapback-finished', N)], N), 'resting')
check('trace second-pointer-down then dismiss-accepted', solve('committing', [('second-pointer-down', N), ('dismiss-accepted', N)], N), 'exit-animating')
check('trace second-pointer-down then dismiss-rejected', solve('committing', [('second-pointer-down', N), ('dismiss-rejected', N)], N), 'returning')
check('trace second-pointer-down then second-pointer-down', solve('committing', [('second-pointer-down', N), ('second-pointer-down', N)], N), 'committing')
check('domain state regression 1: offset', solve('dragging', [('above-threshold-release', N, {'offset': 39})], N, {}, 'offset'), {'phase': 'returning', 'value': 39})
check('domain state regression 2: offset', solve('dragging', [('below-threshold-release', N, {'offset': -40})], N, {}, 'offset'), {'phase': 'committing', 'value': -40})
check('domain state regression 3: offset', solve('dragging', [('above-threshold-release', N, {'pointer': 6, 'offset': 90})], N, {}, 'offset'), {'phase': 'dragging', 'value': 0})
check('domain state regression 4: offset', solve('returning', [('snapback-finished', N, {})], N, {'offset': 25}, 'offset'), {'phase': 'resting', 'value': 0})
check('domain state regression 5: removed', solve('exit-animating', [('reduced-motion-enabled', N, {})], N, {}, 'removed'), {'phase': 'dismissed', 'value': True})
check('domain state regression 6: removed', solve('committing', [('dismiss-rejected', N, {})], N, {'offset': 50}, 'removed'), {'phase': 'returning', 'value': False})
check('domain state regression 7: offset', solve('resting', [('drag-start', N, {}), ('above-threshold-release', N, {'offset': 39}), ('snapback-finished', N, {})], N, {}, 'offset'), {'phase': 'resting', 'value': 0})
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
resting / drag-startdraggingdraggingPassed
dragging / below-threshold-releasedismissedreturningFailed
dragging / above-threshold-releasecommittingcommittingPassed
returning / snapback-finishedrestingrestingPassed
committing / dismiss-acceptedexit-animatingexit-animatingPassed
committing / dismiss-rejectedreturningreturningPassed
exit-animating / animation-finisheddismisseddismissedPassed
dragging / pointer-cancelreturningreturningPassed
exit-animating / reduced-motion-enableddismisseddismissedPassed
committing / second-pointer-downcommittingcommittingPassed
older notification incarnationrestingrestingPassed
future notification incarnationrestingrestingPassed
unknown event is inertrestingrestingPassed
empty delivery batchrestingrestingPassed
N stale deliveries before current deliverydraggingdraggingPassed
trace drag-start then below-threshold-releasedismissedreturningFailed
trace drag-start then above-threshold-releasecommittingcommittingPassed
trace drag-start then pointer-cancelreturningreturningPassed
trace below-threshold-release then snapback-finisheddismissedrestingFailed
trace above-threshold-release then dismiss-acceptedexit-animatingexit-animatingPassed
trace above-threshold-release then dismiss-rejectedreturningreturningPassed
trace above-threshold-release then second-pointer-downcommittingcommittingPassed
trace snapback-finished then drag-startdraggingdraggingPassed
trace dismiss-accepted then animation-finisheddismisseddismissedPassed
trace dismiss-accepted then reduced-motion-enableddismisseddismissedPassed
trace dismiss-rejected then snapback-finishedrestingrestingPassed
trace pointer-cancel then snapback-finishedrestingrestingPassed
trace second-pointer-down then dismiss-acceptedexit-animatingexit-animatingPassed
trace second-pointer-down then dismiss-rejectedreturningreturningPassed
trace second-pointer-down then second-pointer-downcommittingcommittingPassed
domain state regression 1: offset{'phase': 'dismissed', 'value': 39}{'phase': 'returning', 'value': 39}Failed
domain state regression 2: offset{'phase': 'committing', 'value': -40}{'phase': 'committing', 'value': -40}Passed
domain state regression 3: offset{'phase': 'dragging', 'value': 0}{'phase': 'dragging', 'value': 0}Passed
domain state regression 4: offset{'phase': 'resting', 'value': 0}{'phase': 'resting', 'value': 0}Passed
domain state regression 5: removed{'phase': 'dismissed', 'value': True}{'phase': 'dismissed', 'value': True}Passed
domain state regression 6: removed{'phase': 'returning', 'value': False}{'phase': 'returning', 'value': False}Passed
domain state regression 7: offset{'phase': 'dismissed', 'value': 39}{'phase': 'resting', 'value': 0}Failed

SHA-256 / 4d5461a39b28ea50993bf7b289e5e05f6681f30d989b9c03e216f912fe3c82e4

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 = {('resting', 'drag-start'): 'dragging', ('dragging', 'below-threshold-release'): 'committing', ('dragging', 'above-threshold-release'): 'committing', ('returning', 'snapback-finished'): 'resting', ('committing', 'dismiss-accepted'): 'exit-animating', ('committing', 'dismiss-rejected'): 'returning', ('exit-animating', 'animation-finished'): 'dismissed', ('dragging', 'pointer-cancel'): 'returning', ('exit-animating', 'reduced-motion-enabled'): 'dismissed', ('committing', 'second-pointer-down'): 'committing'}
    data = json.loads(json.dumps({'offset': 0, 'threshold': 40, 'pointer': 7, 'removed': False})) if payload is None else {**json.loads(json.dumps({'offset': 0, 'threshold': 40, 'pointer': 7, 'removed': 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 in ('below-threshold-release','above-threshold-release','pointer-cancel') and arg.get('pointer',data['pointer']) != data['pointer']: event = 'unknown-event'
            if event in ('below-threshold-release','above-threshold-release') and 'offset' in arg:
                data['offset'] = arg['offset']
                event = 'above-threshold-release' if abs(data['offset']) >= data['threshold'] else 'below-threshold-release'
            state = table.get((state, event), state)
            if state == 'resting': data['offset'] = 0
            if state == 'dismissed': data['removed'] = True
    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('resting / drag-start', solve('resting', [('drag-start', N)], N), 'dragging')
check('dragging / below-threshold-release', solve('dragging', [('below-threshold-release', N)], N), 'returning')
check('dragging / above-threshold-release', solve('dragging', [('above-threshold-release', N)], N), 'committing')
check('returning / snapback-finished', solve('returning', [('snapback-finished', N)], N), 'resting')
check('committing / dismiss-accepted', solve('committing', [('dismiss-accepted', N)], N), 'exit-animating')
check('committing / dismiss-rejected', solve('committing', [('dismiss-rejected', N)], N), 'returning')
check('exit-animating / animation-finished', solve('exit-animating', [('animation-finished', N)], N), 'dismissed')
check('dragging / pointer-cancel', solve('dragging', [('pointer-cancel', N)], N), 'returning')
check('exit-animating / reduced-motion-enabled', solve('exit-animating', [('reduced-motion-enabled', N)], N), 'dismissed')
check('committing / second-pointer-down', solve('committing', [('second-pointer-down', N)], N), 'committing')
check('older notification incarnation', solve('resting', [('drag-start', N - 1)], N), 'resting')
check('future notification incarnation', solve('resting', [('drag-start', N + 1)], N), 'resting')
check('unknown event is inert', solve('resting', [('unknown-event', N)], N), 'resting')
check('empty delivery batch', solve('resting', [], N), 'resting')
check('N stale deliveries before current delivery', solve('resting', [('drag-start', N - 1)] * N + [('drag-start', N)], N), 'dragging')
check('trace drag-start then below-threshold-release', solve('resting', [('drag-start', N), ('below-threshold-release', N)], N), 'returning')
check('trace drag-start then above-threshold-release', solve('resting', [('drag-start', N), ('above-threshold-release', N)], N), 'committing')
check('trace drag-start then pointer-cancel', solve('resting', [('drag-start', N), ('pointer-cancel', N)], N), 'returning')
check('trace below-threshold-release then snapback-finished', solve('dragging', [('below-threshold-release', N), ('snapback-finished', N)], N), 'resting')
check('trace above-threshold-release then dismiss-accepted', solve('dragging', [('above-threshold-release', N), ('dismiss-accepted', N)], N), 'exit-animating')
check('trace above-threshold-release then dismiss-rejected', solve('dragging', [('above-threshold-release', N), ('dismiss-rejected', N)], N), 'returning')
check('trace above-threshold-release then second-pointer-down', solve('dragging', [('above-threshold-release', N), ('second-pointer-down', N)], N), 'committing')
check('trace snapback-finished then drag-start', solve('returning', [('snapback-finished', N), ('drag-start', N)], N), 'dragging')
check('trace dismiss-accepted then animation-finished', solve('committing', [('dismiss-accepted', N), ('animation-finished', N)], N), 'dismissed')
check('trace dismiss-accepted then reduced-motion-enabled', solve('committing', [('dismiss-accepted', N), ('reduced-motion-enabled', N)], N), 'dismissed')
check('trace dismiss-rejected then snapback-finished', solve('committing', [('dismiss-rejected', N), ('snapback-finished', N)], N), 'resting')
check('trace pointer-cancel then snapback-finished', solve('dragging', [('pointer-cancel', N), ('snapback-finished', N)], N), 'resting')
check('trace second-pointer-down then dismiss-accepted', solve('committing', [('second-pointer-down', N), ('dismiss-accepted', N)], N), 'exit-animating')
check('trace second-pointer-down then dismiss-rejected', solve('committing', [('second-pointer-down', N), ('dismiss-rejected', N)], N), 'returning')
check('trace second-pointer-down then second-pointer-down', solve('committing', [('second-pointer-down', N), ('second-pointer-down', N)], N), 'committing')
check('domain state regression 1: offset', solve('dragging', [('above-threshold-release', N, {'offset': 39})], N, {}, 'offset'), {'phase': 'returning', 'value': 39})
check('domain state regression 2: offset', solve('dragging', [('below-threshold-release', N, {'offset': -40})], N, {}, 'offset'), {'phase': 'committing', 'value': -40})
check('domain state regression 3: offset', solve('dragging', [('above-threshold-release', N, {'pointer': 6, 'offset': 90})], N, {}, 'offset'), {'phase': 'dragging', 'value': 0})
check('domain state regression 4: offset', solve('returning', [('snapback-finished', N, {})], N, {'offset': 25}, 'offset'), {'phase': 'resting', 'value': 0})
check('domain state regression 5: removed', solve('exit-animating', [('reduced-motion-enabled', N, {})], N, {}, 'removed'), {'phase': 'dismissed', 'value': True})
check('domain state regression 6: removed', solve('committing', [('dismiss-rejected', N, {})], N, {'offset': 50}, 'removed'), {'phase': 'returning', 'value': False})
check('domain state regression 7: offset', solve('resting', [('drag-start', N, {}), ('above-threshold-release', N, {'offset': 39}), ('snapback-finished', N, {})], N, {}, 'offset'), {'phase': 'resting', 'value': 0})
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
resting / drag-startdraggingdraggingPassed
dragging / below-threshold-releasecommittingreturningFailed
dragging / above-threshold-releasecommittingcommittingPassed
returning / snapback-finishedrestingrestingPassed
committing / dismiss-acceptedexit-animatingexit-animatingPassed
committing / dismiss-rejectedreturningreturningPassed
exit-animating / animation-finisheddismisseddismissedPassed
dragging / pointer-cancelreturningreturningPassed
exit-animating / reduced-motion-enableddismisseddismissedPassed
committing / second-pointer-downcommittingcommittingPassed
older notification incarnationrestingrestingPassed
future notification incarnationrestingrestingPassed
unknown event is inertrestingrestingPassed
empty delivery batchrestingrestingPassed
N stale deliveries before current deliverydraggingdraggingPassed
trace drag-start then below-threshold-releasecommittingreturningFailed
trace drag-start then above-threshold-releasecommittingcommittingPassed
trace drag-start then pointer-cancelreturningreturningPassed
trace below-threshold-release then snapback-finishedcommittingrestingFailed
trace above-threshold-release then dismiss-acceptedexit-animatingexit-animatingPassed
trace above-threshold-release then dismiss-rejectedreturningreturningPassed
trace above-threshold-release then second-pointer-downcommittingcommittingPassed
trace snapback-finished then drag-startdraggingdraggingPassed
trace dismiss-accepted then animation-finisheddismisseddismissedPassed
trace dismiss-accepted then reduced-motion-enableddismisseddismissedPassed
trace dismiss-rejected then snapback-finishedrestingrestingPassed
trace pointer-cancel then snapback-finishedrestingrestingPassed
trace second-pointer-down then dismiss-acceptedexit-animatingexit-animatingPassed
trace second-pointer-down then dismiss-rejectedreturningreturningPassed
trace second-pointer-down then second-pointer-downcommittingcommittingPassed
domain state regression 1: offset{'phase': 'committing', 'value': 39}{'phase': 'returning', 'value': 39}Failed
domain state regression 2: offset{'phase': 'committing', 'value': -40}{'phase': 'committing', 'value': -40}Passed
domain state regression 3: offset{'phase': 'dragging', 'value': 0}{'phase': 'dragging', 'value': 0}Passed
domain state regression 4: offset{'phase': 'resting', 'value': 0}{'phase': 'resting', 'value': 0}Passed
domain state regression 5: removed{'phase': 'dismissed', 'value': True}{'phase': 'dismissed', 'value': True}Passed
domain state regression 6: removed{'phase': 'returning', 'value': False}{'phase': 'returning', 'value': False}Passed
domain state regression 7: offset{'phase': 'committing', 'value': 39}{'phase': 'resting', 'value': 0}Failed

SHA-256 / f48141a96db17877927e571866d5524ce12e62b00a784b1497a1e53f778e16a2

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 37 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 2026-09-29T14:42:32.841744+00:00.

Case digest / cee3012c65d1985f4d374827aee6134be5b497602f54f240c6847c8cb320654a