FA-8921 / Selection controls / Open access

Rating preview and committed value: Repeated activation clears a nonclearable rating · case 01

Repeated activation clears a nonclearable rating.

Verified by executionVariant 1 · 9 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The clear policy operation uses `value == committed` where the contract requires `allow_clear and value == committed`.

VERIFIED REPAIR

Implement the clear policy operation as `allow_clear and value == committed`.

Unsuccessful approach: Always clearing when allowed prevents changing to a different rating.

Case contract

Hover changes preview only; leaving or Escape discards preview; activation commits and clears preview; repeated activation clears only when allowed; readonly ignores interaction and has no preview.

Why this case matters

A deterministic model of rating preview and committed value; this isolates one interface invariant without requiring a browser.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(committed, preview, event, value, readonly, allow_clear):
    if readonly: return (committed, None)
    if event == 'hover': preview = value
    elif event == 'leave': preview = None
    elif event == 'activate':
        committed = None if value == committed else value
        preview = None
    elif event == 'escape': preview = None
    return (committed, preview)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('readonly', solve(2, 4, 'activate', 5, True, True), (2, None))
check('hover', solve(2, None, 'hover', 4, False, True), (2, 4))
check('leave', solve(2, 4, 'leave', None, False, True), (2, None))
check('locked clear', solve(2, 4, 'activate', 2, False, False), (2, None))
check('change', solve(2, 4, 'activate', 5, False, True), (5, None))
check('clear', solve(2, 4, 'activate', 2, False, True), (None, None))
check('escape', solve(2, 4, 'escape', None, False, True), (2, None))
check('parameterized rating preview', solve(0,None,'hover',N,False,False), (0,N))
for repetition in range(N):
    check('repeat escape', solve(2, 4, 'escape', None, False, True), (2, 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
readonly	`[2, None]`	`[2, None]`	Passed
hover	`[2, 4]`	`[2, 4]`	Passed
leave	`[2, None]`	`[2, None]`	Passed
locked clear	`[None, None]`	`[2, None]`	Failed
change	`[5, None]`	`[5, None]`	Passed
clear	`[None, None]`	`[None, None]`	Passed
escape	`[2, None]`	`[2, None]`	Passed
parameterized rating preview	`[0, 1]`	`[0, 1]`	Passed
repeat escape	`[2, None]`	`[2, None]`	Passed

SHA-256 / bed989b65b421a1f3b4cc191debe216a2573c705414630eeb7e5e81d5722c770

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(committed, preview, event, value, readonly, allow_clear):
    if readonly: return (committed, None)
    if event == 'hover': preview = value
    elif event == 'leave': preview = None
    elif event == 'activate':
        committed = None if allow_clear else value
        preview = None
    elif event == 'escape': preview = None
    return (committed, preview)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('readonly', solve(2, 4, 'activate', 5, True, True), (2, None))
check('hover', solve(2, None, 'hover', 4, False, True), (2, 4))
check('leave', solve(2, 4, 'leave', None, False, True), (2, None))
check('locked clear', solve(2, 4, 'activate', 2, False, False), (2, None))
check('change', solve(2, 4, 'activate', 5, False, True), (5, None))
check('clear', solve(2, 4, 'activate', 2, False, True), (None, None))
check('escape', solve(2, 4, 'escape', None, False, True), (2, None))
check('parameterized rating preview', solve(0,None,'hover',N,False,False), (0,N))
for repetition in range(N):
    check('repeat escape', solve(2, 4, 'escape', None, False, True), (2, 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
readonly	`[2, None]`	`[2, None]`	Passed
hover	`[2, 4]`	`[2, 4]`	Passed
leave	`[2, None]`	`[2, None]`	Passed
locked clear	`[2, None]`	`[2, None]`	Passed
change	`[None, None]`	`[5, None]`	Failed
clear	`[None, None]`	`[None, None]`	Passed
escape	`[2, None]`	`[2, None]`	Passed
parameterized rating preview	`[0, 1]`	`[0, 1]`	Passed
repeat escape	`[2, None]`	`[2, None]`	Passed

SHA-256 / 5e2de7528ebebda8ef9cc173483619339baa863ad38cf27e8492364d7d64ee11

3 / The verified repair

Exit 0

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

N = 1
observations = []
def solve(committed, preview, event, value, readonly, allow_clear):
    if readonly: return (committed, None)
    if event == 'hover': preview = value
    elif event == 'leave': preview = None
    elif event == 'activate':
        committed = None if allow_clear and value == committed else value
        preview = None
    elif event == 'escape': preview = None
    return (committed, preview)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('readonly', solve(2, 4, 'activate', 5, True, True), (2, None))
check('hover', solve(2, None, 'hover', 4, False, True), (2, 4))
check('leave', solve(2, 4, 'leave', None, False, True), (2, None))
check('locked clear', solve(2, 4, 'activate', 2, False, False), (2, None))
check('change', solve(2, 4, 'activate', 5, False, True), (5, None))
check('clear', solve(2, 4, 'activate', 2, False, True), (None, None))
check('escape', solve(2, 4, 'escape', None, False, True), (2, None))
check('parameterized rating preview', solve(0,None,'hover',N,False,False), (0,N))
for repetition in range(N):
    check('repeat escape', solve(2, 4, 'escape', None, False, True), (2, 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
readonly	`[2, None]`	`[2, None]`	Passed
hover	`[2, 4]`	`[2, 4]`	Passed
leave	`[2, None]`	`[2, None]`	Passed
locked clear	`[2, None]`	`[2, None]`	Passed
change	`[5, None]`	`[5, None]`	Passed
clear	`[None, None]`	`[None, None]`	Passed
escape	`[2, None]`	`[2, None]`	Passed
parameterized rating preview	`[0, 1]`	`[0, 1]`	Passed
repeat escape	`[2, None]`	`[2, None]`	Passed

SHA-256 / 9f20e0513182a40341ff5a62f79fe9d3059692f49d84ac783ee44ceec4099d15

Verification & scope

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 2026-09-29T14:38:25.581216+00:00.

Case digest / 0d50dab2fdf1ec007ec552358f8ea49ec1e18d1a2b04fc5243893fe3005eebfe