FA-7931 / Selection controls / Open access
Hierarchical checkbox state: Selecting a subtree erases selections outside it · case 01
Selecting a subtree erases selections outside it.
ROOT CAUSE
The select all operation uses `selected = children` where the contract requires `selected |= children`.
VERIFIED REPAIR
Implement the select all operation as `selected |= children`.
Unsuccessful approach: Toggling descendants deselects already selected children.
Case contract
Subtree actions preserve outside selections; toggle is symmetric; parent status depends only on selected descendants and distinguishes none, mixed and all.
Why this case matters
A deterministic model of hierarchical checkbox state; 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(selected, children, event, child):
selected = set(selected)
children = set(children)
if event == 'all': selected = children
elif event == 'none': selected -= children
elif event == 'toggle': selected.symmetric_difference_update({child})
visible = selected & children
state = 'none' if not visible else ('all' if visible == children else 'mixed')
return (sorted(selected), state)
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('all keeps outside', solve(['x','a'], ['a','b'], 'all', None), (['a', 'b', 'x'], 'all'))
check('none keeps outside', solve(['x','a'], ['a','b'], 'none', None), (['x'], 'none'))
check('toggle off', solve(['a'], ['a','b'], 'toggle', 'a'), ([], 'none'))
check('toggle on', solve([], ['a','b'], 'toggle', 'a'), (['a'], 'mixed'))
check('outside only', solve(['x'], ['a','b'], 'read', None), (['x'], 'none'))
check('all', solve(['a','b'], ['a','b'], 'read', None), (['a', 'b'], 'all'))
check('parameterized checked subtree', solve(list(range(N)), list(range(N)), 'read', None), (list(range(N)), 'all'))
for repetition in range(N):
check('repeat all', solve(['a','b'], ['a','b'], 'read', None), (['a', 'b'], 'all'))
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 |
|---|---|---|---|
| all keeps outside | [['a', 'b'], 'all'] | [['a', 'b', 'x'], 'all'] | Failed |
| none keeps outside | [['x'], 'none'] | [['x'], 'none'] | Passed |
| toggle off | [[], 'none'] | [[], 'none'] | Passed |
| toggle on | [['a'], 'mixed'] | [['a'], 'mixed'] | Passed |
| outside only | [['x'], 'none'] | [['x'], 'none'] | Passed |
| all | [['a', 'b'], 'all'] | [['a', 'b'], 'all'] | Passed |
| parameterized checked subtree | [[0], 'all'] | [[0], 'all'] | Passed |
| repeat all | [['a', 'b'], 'all'] | [['a', 'b'], 'all'] | Passed |
SHA-256 / d76ff1b24df741f88b725bbf5ea44f9adc59b36e6e2b8ed5c9e7168562b3f2a9
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(selected, children, event, child):
selected = set(selected)
children = set(children)
if event == 'all': selected ^= children
elif event == 'none': selected -= children
elif event == 'toggle': selected.symmetric_difference_update({child})
visible = selected & children
state = 'none' if not visible else ('all' if visible == children else 'mixed')
return (sorted(selected), state)
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('all keeps outside', solve(['x','a'], ['a','b'], 'all', None), (['a', 'b', 'x'], 'all'))
check('none keeps outside', solve(['x','a'], ['a','b'], 'none', None), (['x'], 'none'))
check('toggle off', solve(['a'], ['a','b'], 'toggle', 'a'), ([], 'none'))
check('toggle on', solve([], ['a','b'], 'toggle', 'a'), (['a'], 'mixed'))
check('outside only', solve(['x'], ['a','b'], 'read', None), (['x'], 'none'))
check('all', solve(['a','b'], ['a','b'], 'read', None), (['a', 'b'], 'all'))
check('parameterized checked subtree', solve(list(range(N)), list(range(N)), 'read', None), (list(range(N)), 'all'))
for repetition in range(N):
check('repeat all', solve(['a','b'], ['a','b'], 'read', None), (['a', 'b'], 'all'))
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 |
|---|---|---|---|
| all keeps outside | [['b', 'x'], 'mixed'] | [['a', 'b', 'x'], 'all'] | Failed |
| none keeps outside | [['x'], 'none'] | [['x'], 'none'] | Passed |
| toggle off | [[], 'none'] | [[], 'none'] | Passed |
| toggle on | [['a'], 'mixed'] | [['a'], 'mixed'] | Passed |
| outside only | [['x'], 'none'] | [['x'], 'none'] | Passed |
| all | [['a', 'b'], 'all'] | [['a', 'b'], 'all'] | Passed |
| parameterized checked subtree | [[0], 'all'] | [[0], 'all'] | Passed |
| repeat all | [['a', 'b'], 'all'] | [['a', 'b'], 'all'] | Passed |
SHA-256 / 322b0cad5dd520e6731838c5c2541ae109d740365d10673381af5ffdac272618
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(selected, children, event, child):
selected = set(selected)
children = set(children)
if event == 'all': selected |= children
elif event == 'none': selected -= children
elif event == 'toggle': selected.symmetric_difference_update({child})
visible = selected & children
state = 'none' if not visible else ('all' if visible == children else 'mixed')
return (sorted(selected), state)
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('all keeps outside', solve(['x','a'], ['a','b'], 'all', None), (['a', 'b', 'x'], 'all'))
check('none keeps outside', solve(['x','a'], ['a','b'], 'none', None), (['x'], 'none'))
check('toggle off', solve(['a'], ['a','b'], 'toggle', 'a'), ([], 'none'))
check('toggle on', solve([], ['a','b'], 'toggle', 'a'), (['a'], 'mixed'))
check('outside only', solve(['x'], ['a','b'], 'read', None), (['x'], 'none'))
check('all', solve(['a','b'], ['a','b'], 'read', None), (['a', 'b'], 'all'))
check('parameterized checked subtree', solve(list(range(N)), list(range(N)), 'read', None), (list(range(N)), 'all'))
for repetition in range(N):
check('repeat all', solve(['a','b'], ['a','b'], 'read', None), (['a', 'b'], 'all'))
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 |
|---|---|---|---|
| all keeps outside | [['a', 'b', 'x'], 'all'] | [['a', 'b', 'x'], 'all'] | Passed |
| none keeps outside | [['x'], 'none'] | [['x'], 'none'] | Passed |
| toggle off | [[], 'none'] | [[], 'none'] | Passed |
| toggle on | [['a'], 'mixed'] | [['a'], 'mixed'] | Passed |
| outside only | [['x'], 'none'] | [['x'], 'none'] | Passed |
| all | [['a', 'b'], 'all'] | [['a', 'b'], 'all'] | Passed |
| parameterized checked subtree | [[0], 'all'] | [[0], 'all'] | Passed |
| repeat all | [['a', 'b'], 'all'] | [['a', 'b'], 'all'] | Passed |
SHA-256 / 8601b5edb6a2428e9f04dc68f017ac8fa14035179bf7c42f7b2dc6a5cc451f6a
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 2026-09-29T14:38:16.656441+00:00.
Case digest / 7a3496b84e1cb3a35d05da01691563048bc04d2e043ba98739dca77504ee4748