FA-8911 / Selection controls / Open access

Rating preview and committed value: Hovering commits a rating before activation · case 01

Hovering commits a rating before activation.

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

ROOT CAUSE

The hover operation uses `if event == 'hover': committed = value` where the contract requires `if event == 'hover': preview = value`.

VERIFIED REPAIR

Implement the hover operation as `if event == 'hover': preview = value`.

Unsuccessful approach: Previewing the old rating provides no hover feedback.

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': committed = 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	`[4, None]`	`[2, 4]`	Failed
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	`[1, None]`	`[0, 1]`	Failed
repeat escape	`[2, None]`	`[2, None]`	Passed

SHA-256 / d0e20eb63475037714b9f576b49a654bd95784f255490e2791be009279ee3c83

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 = committed
    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, 2]`	`[2, 4]`	Failed
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, 0]`	`[0, 1]`	Failed
repeat escape	`[2, None]`	`[2, None]`	Passed

SHA-256 / 1503af679837476b13531937ce94ca1b6768aa735f6e11f0d5cec4a68fad3fde

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 2026-09-29T14:38:25.509654+00:00.

Case digest / 06e4b4cafa399df021b00119b3743204542df2116ce870a9dbcf3e3e37bfe5a2