FA-22576 / Autocomplete interactions / Open access

Suggestion pointer acceptance transaction: pointer hover commits a suggestion before acceptance · case 01

The hover-value completion transition produces an incorrect observable state.

Verified by executionVariant 1 · 22 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

At pointer-acceptance/hover-value, the implementation evaluates `d['hover']` instead of preserving the specified completion transition.

THE FAILURE

At pointer-acceptance/hover-value, the implementation evaluates `d['hover']` instead of preserving the specified completion transition.

Unsuccessful approach: The attempted repair uses `None`, which still violates a normal or boundary completion fixture.

Case contract

Pointer acceptance captures option identity on press; release must match the captured pointer and row, remain inside, and exceed neither drag slop nor query epoch. Blur defers while a valid option press is pending. Hover is only preview and never a value commit.

Why this case matters

Autocomplete couples draft text, suggestion identity and asynchronous presentation; this bounded lifecycle model isolates one observable interaction defect.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(event, d):
    if event == 'capture': return d['pressed']
    if event == 'same-row': return d['pressed'] is not None and d['pressed']==d['released']
    if event == 'same-pointer': return d['pointer']==d['release_pointer']
    if event == 'inside': return d['inside']
    if event == 'slop': return d['distance']<=d['slop']
    if event == 'fresh': return d['press_epoch']==d['epoch']
    if event == 'blur-defer': return d['pressed'] is not None
    if event == 'hover-value': return d['hover']
    if event == 'cancel': return {'pressed':None,'pointer':None}
    if event == 'press-epoch': return d['epoch']
    return {'unchanged': True}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
normal = {'pressed':'a','released':'b','pointer':N,'release_pointer':N+1,'inside':False,'distance':8,'slop':3,'epoch':N,'press_epoch':N-1,'hover':'c','value':'v'}
boundary = {'pressed':None,'released':None,'pointer':N,'release_pointer':N,'inside':True,'distance':0,'slop':0,'epoch':N,'press_epoch':N,'hover':None,'value':None}
check('normal capture', solve('capture', normal), 'a')
check('boundary capture', solve('capture', boundary), None)
check('normal same-row', solve('same-row', normal), False)
check('boundary same-row', solve('same-row', boundary), False)
check('normal same-pointer', solve('same-pointer', normal), False)
check('boundary same-pointer', solve('same-pointer', boundary), True)
check('normal inside', solve('inside', normal), False)
check('boundary inside', solve('inside', boundary), True)
check('normal slop', solve('slop', normal), False)
check('boundary slop', solve('slop', boundary), True)
check('normal fresh', solve('fresh', normal), False)
check('boundary fresh', solve('fresh', boundary), True)
check('normal blur-defer', solve('blur-defer', normal), True)
check('boundary blur-defer', solve('blur-defer', boundary), False)
check('normal hover-value', solve('hover-value', normal), 'v')
check('boundary hover-value', solve('hover-value', boundary), None)
check('normal cancel', solve('cancel', normal), {'pressed':None,'pointer':None})
check('boundary cancel', solve('cancel', boundary), {'pressed':None,'pointer':None})
check('normal press-epoch', solve('press-epoch', normal), N)
check('boundary press-epoch', solve('press-epoch', boundary), N)
variant = dict(normal, **{'pressed':'id'+str(N)})
check('variant query or selection payload', solve('capture', variant), 'id'+str(N))
check('unknown completion event', solve('unrecognized', normal), {'unchanged': 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 fixture	Actual	Expected	Outcome
normal capture	`a`	`a`	Passed
boundary capture	`None`	`None`	Passed
normal same-row	`False`	`False`	Passed
boundary same-row	`False`	`False`	Passed
normal same-pointer	`False`	`False`	Passed
boundary same-pointer	`True`	`True`	Passed
normal inside	`False`	`False`	Passed
boundary inside	`True`	`True`	Passed
normal slop	`False`	`False`	Passed
boundary slop	`True`	`True`	Passed
normal fresh	`False`	`False`	Passed
boundary fresh	`True`	`True`	Passed
normal blur-defer	`True`	`True`	Passed
boundary blur-defer	`False`	`False`	Passed
normal hover-value	`c`	`v`	Failed
boundary hover-value	`None`	`None`	Passed
normal cancel	`{'pointer': None, 'pressed': None}`	`{'pointer': None, 'pressed': None}`	Passed
boundary cancel	`{'pointer': None, 'pressed': None}`	`{'pointer': None, 'pressed': None}`	Passed
normal press-epoch	`1`	`1`	Passed
boundary press-epoch	`1`	`1`	Passed
variant query or selection payload	`id1`	`id1`	Passed
unknown completion event	`{'unchanged': True}`	`{'unchanged': True}`	Passed

SHA-256 / 83bdbeaf520d6fec38ae1602702e7556432cb9276e522d4476e02e5b79bf34be

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(event, d):
    if event == 'capture': return d['pressed']
    if event == 'same-row': return d['pressed'] is not None and d['pressed']==d['released']
    if event == 'same-pointer': return d['pointer']==d['release_pointer']
    if event == 'inside': return d['inside']
    if event == 'slop': return d['distance']<=d['slop']
    if event == 'fresh': return d['press_epoch']==d['epoch']
    if event == 'blur-defer': return d['pressed'] is not None
    if event == 'hover-value': return None
    if event == 'cancel': return {'pressed':None,'pointer':None}
    if event == 'press-epoch': return d['epoch']
    return {'unchanged': True}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
normal = {'pressed':'a','released':'b','pointer':N,'release_pointer':N+1,'inside':False,'distance':8,'slop':3,'epoch':N,'press_epoch':N-1,'hover':'c','value':'v'}
boundary = {'pressed':None,'released':None,'pointer':N,'release_pointer':N,'inside':True,'distance':0,'slop':0,'epoch':N,'press_epoch':N,'hover':None,'value':None}
check('normal capture', solve('capture', normal), 'a')
check('boundary capture', solve('capture', boundary), None)
check('normal same-row', solve('same-row', normal), False)
check('boundary same-row', solve('same-row', boundary), False)
check('normal same-pointer', solve('same-pointer', normal), False)
check('boundary same-pointer', solve('same-pointer', boundary), True)
check('normal inside', solve('inside', normal), False)
check('boundary inside', solve('inside', boundary), True)
check('normal slop', solve('slop', normal), False)
check('boundary slop', solve('slop', boundary), True)
check('normal fresh', solve('fresh', normal), False)
check('boundary fresh', solve('fresh', boundary), True)
check('normal blur-defer', solve('blur-defer', normal), True)
check('boundary blur-defer', solve('blur-defer', boundary), False)
check('normal hover-value', solve('hover-value', normal), 'v')
check('boundary hover-value', solve('hover-value', boundary), None)
check('normal cancel', solve('cancel', normal), {'pressed':None,'pointer':None})
check('boundary cancel', solve('cancel', boundary), {'pressed':None,'pointer':None})
check('normal press-epoch', solve('press-epoch', normal), N)
check('boundary press-epoch', solve('press-epoch', boundary), N)
variant = dict(normal, **{'pressed':'id'+str(N)})
check('variant query or selection payload', solve('capture', variant), 'id'+str(N))
check('unknown completion event', solve('unrecognized', normal), {'unchanged': 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 fixture	Actual	Expected	Outcome
normal capture	`a`	`a`	Passed
boundary capture	`None`	`None`	Passed
normal same-row	`False`	`False`	Passed
boundary same-row	`False`	`False`	Passed
normal same-pointer	`False`	`False`	Passed
boundary same-pointer	`True`	`True`	Passed
normal inside	`False`	`False`	Passed
boundary inside	`True`	`True`	Passed
normal slop	`False`	`False`	Passed
boundary slop	`True`	`True`	Passed
normal fresh	`False`	`False`	Passed
boundary fresh	`True`	`True`	Passed
normal blur-defer	`True`	`True`	Passed
boundary blur-defer	`False`	`False`	Passed
normal hover-value	`None`	`v`	Failed
boundary hover-value	`None`	`None`	Passed
normal cancel	`{'pointer': None, 'pressed': None}`	`{'pointer': None, 'pressed': None}`	Passed
boundary cancel	`{'pointer': None, 'pressed': None}`	`{'pointer': None, 'pressed': None}`	Passed
normal press-epoch	`1`	`1`	Passed
boundary press-epoch	`1`	`1`	Passed
variant query or selection payload	`id1`	`id1`	Passed
unknown completion event	`{'unchanged': True}`	`{'unchanged': True}`	Passed

SHA-256 / a2949df904b8f5313e82f196b880258b2b7597a23db92749110fd833efe0a1dc

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 22 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.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

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

Verification & scope

Stipulated deterministic widget transition model; inputs are validated snapshots. It does not model browser event dispatch, network transport, or linguistic standards. 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 2026-09-29T14:40:39.698626+00:00.

Case digest / 758cfcc6fd91a3a28c7abc5d2d174770f96dab028a2f525f49a58ea222942808