FA-22456 / Autocomplete interactions / Open access

Autocomplete loading and empty states: old-query failure overwrites current autocomplete status · case 01

The error completion transition produces an incorrect observable state.

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

ROOT CAUSE

At loading-presentation/error, the implementation evaluates `d['error']` instead of preserving the specified completion transition.

THE FAILURE

At loading-presentation/error, the implementation evaluates `d['error']` instead of preserving the specified completion transition.

Unsuccessful approach: The attempted repair uses `d['error'] if d['error_epoch']<=d['epoch'] else None`, which still violates a normal or boundary completion fixture.

Case contract

A loading snapshot distinguishes initial loading, background refreshing, settled-empty, error and cancellation. Only settled successful empty responses show no-results. Existing rows may remain visible during refresh but are bound to the draft they represent; stale errors never overwrite a newer query status.

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 == 'initial': return d['pending'] and not d['rows']
    if event == 'refreshing': return d['pending'] and bool(d['rows'])
    if event == 'empty': return d['settled'] and not d['pending'] and not d['rows'] and d['error'] is None
    if event == 'error': return d['error']
    if event == 'selectable': return d['rows'] if d['rows_query']==d['query'] else []
    if event == 'cancel': return None if d['cancelled'] else d['error']
    if event == 'busy': return d['pending']
    if event == 'preserve': return d['rows']
    if event == 'status-priority': return 'error' if d['error'] else 'loading' if d['pending'] else 'empty' if not d['rows'] else 'results'
    if event == 'retry-label': return {'query':d['query'],'error':d['error']}
    return {'unchanged': True}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
normal = {'pending':True,'rows':['a'],'query':'pe','rows_query':'p','error':'timeout','error_epoch':N-1,'epoch':N,'settled':False,'cancelled':True}
boundary = {'pending':False,'rows':[],'query':'','rows_query':'','error':None,'error_epoch':N,'epoch':N,'settled':True,'cancelled':False}
check('normal initial', solve('initial', normal), False)
check('boundary initial', solve('initial', boundary), False)
check('normal refreshing', solve('refreshing', normal), True)
check('boundary refreshing', solve('refreshing', boundary), False)
check('normal empty', solve('empty', normal), False)
check('boundary empty', solve('empty', boundary), True)
check('normal error', solve('error', normal), None)
check('boundary error', solve('error', boundary), None)
check('normal selectable', solve('selectable', normal), [])
check('boundary selectable', solve('selectable', boundary), [])
check('normal cancel', solve('cancel', normal), None)
check('boundary cancel', solve('cancel', boundary), None)
check('normal busy', solve('busy', normal), True)
check('boundary busy', solve('busy', boundary), False)
check('normal preserve', solve('preserve', normal), ['a'])
check('boundary preserve', solve('preserve', boundary), [])
check('normal status-priority', solve('status-priority', normal), 'error')
check('boundary status-priority', solve('status-priority', boundary), 'empty')
check('normal retry-label', solve('retry-label', normal), {'query':'pe','error':'timeout'})
check('boundary retry-label', solve('retry-label', boundary), {'query':'','error':None})
variant = dict(normal, **{'query':'q'*N})
check('variant query or selection payload', solve('retry-label', variant), {'query':'q'*N,'error':'timeout'})
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 initial	`False`	`False`	Passed
boundary initial	`False`	`False`	Passed
normal refreshing	`True`	`True`	Passed
boundary refreshing	`False`	`False`	Passed
normal empty	`False`	`False`	Passed
boundary empty	`True`	`True`	Passed
normal error	`timeout`	`None`	Failed
boundary error	`None`	`None`	Passed
normal selectable	`[]`	`[]`	Passed
boundary selectable	`[]`	`[]`	Passed
normal cancel	`None`	`None`	Passed
boundary cancel	`None`	`None`	Passed
normal busy	`True`	`True`	Passed
boundary busy	`False`	`False`	Passed
normal preserve	`['a']`	`['a']`	Passed
boundary preserve	`[]`	`[]`	Passed
normal status-priority	`error`	`error`	Passed
boundary status-priority	`empty`	`empty`	Passed
normal retry-label	`{'error': 'timeout', 'query': 'pe'}`	`{'error': 'timeout', 'query': 'pe'}`	Passed
boundary retry-label	`{'error': None, 'query': ''}`	`{'error': None, 'query': ''}`	Passed
variant query or selection payload	`{'error': 'timeout', 'query': 'q'}`	`{'error': 'timeout', 'query': 'q'}`	Passed
unknown completion event	`{'unchanged': True}`	`{'unchanged': True}`	Passed

SHA-256 / 8bda285a4ba0dda349ed597d8d0ae72b3ac1db2858e0623fa22284ef80f70421

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 == 'initial': return d['pending'] and not d['rows']
    if event == 'refreshing': return d['pending'] and bool(d['rows'])
    if event == 'empty': return d['settled'] and not d['pending'] and not d['rows'] and d['error'] is None
    if event == 'error': return d['error'] if d['error_epoch']<=d['epoch'] else None
    if event == 'selectable': return d['rows'] if d['rows_query']==d['query'] else []
    if event == 'cancel': return None if d['cancelled'] else d['error']
    if event == 'busy': return d['pending']
    if event == 'preserve': return d['rows']
    if event == 'status-priority': return 'error' if d['error'] else 'loading' if d['pending'] else 'empty' if not d['rows'] else 'results'
    if event == 'retry-label': return {'query':d['query'],'error':d['error']}
    return {'unchanged': True}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
normal = {'pending':True,'rows':['a'],'query':'pe','rows_query':'p','error':'timeout','error_epoch':N-1,'epoch':N,'settled':False,'cancelled':True}
boundary = {'pending':False,'rows':[],'query':'','rows_query':'','error':None,'error_epoch':N,'epoch':N,'settled':True,'cancelled':False}
check('normal initial', solve('initial', normal), False)
check('boundary initial', solve('initial', boundary), False)
check('normal refreshing', solve('refreshing', normal), True)
check('boundary refreshing', solve('refreshing', boundary), False)
check('normal empty', solve('empty', normal), False)
check('boundary empty', solve('empty', boundary), True)
check('normal error', solve('error', normal), None)
check('boundary error', solve('error', boundary), None)
check('normal selectable', solve('selectable', normal), [])
check('boundary selectable', solve('selectable', boundary), [])
check('normal cancel', solve('cancel', normal), None)
check('boundary cancel', solve('cancel', boundary), None)
check('normal busy', solve('busy', normal), True)
check('boundary busy', solve('busy', boundary), False)
check('normal preserve', solve('preserve', normal), ['a'])
check('boundary preserve', solve('preserve', boundary), [])
check('normal status-priority', solve('status-priority', normal), 'error')
check('boundary status-priority', solve('status-priority', boundary), 'empty')
check('normal retry-label', solve('retry-label', normal), {'query':'pe','error':'timeout'})
check('boundary retry-label', solve('retry-label', boundary), {'query':'','error':None})
variant = dict(normal, **{'query':'q'*N})
check('variant query or selection payload', solve('retry-label', variant), {'query':'q'*N,'error':'timeout'})
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 initial	`False`	`False`	Passed
boundary initial	`False`	`False`	Passed
normal refreshing	`True`	`True`	Passed
boundary refreshing	`False`	`False`	Passed
normal empty	`False`	`False`	Passed
boundary empty	`True`	`True`	Passed
normal error	`timeout`	`None`	Failed
boundary error	`None`	`None`	Passed
normal selectable	`[]`	`[]`	Passed
boundary selectable	`[]`	`[]`	Passed
normal cancel	`None`	`None`	Passed
boundary cancel	`None`	`None`	Passed
normal busy	`True`	`True`	Passed
boundary busy	`False`	`False`	Passed
normal preserve	`['a']`	`['a']`	Passed
boundary preserve	`[]`	`[]`	Passed
normal status-priority	`error`	`error`	Passed
boundary status-priority	`empty`	`empty`	Passed
normal retry-label	`{'error': 'timeout', 'query': 'pe'}`	`{'error': 'timeout', 'query': 'pe'}`	Passed
boundary retry-label	`{'error': None, 'query': ''}`	`{'error': None, 'query': ''}`	Passed
variant query or selection payload	`{'error': 'timeout', 'query': 'q'}`	`{'error': 'timeout', 'query': 'q'}`	Passed
unknown completion event	`{'unchanged': True}`	`{'unchanged': True}`	Passed

SHA-256 / 3417e63effec9b6f582f32880e4cf16339f9646d129e175da33ccac6361f03f2

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 2026-09-29T14:40:38.896271+00:00.

Case digest / 3b1d89a172eaf8799e5861c94e10cf947a420e482e5f476b95f43d5af64be935