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FA-38441 / Tree accessibility / Open access

Virtual tree sibling metadata: Logical sibling position becomes recycled slot number · case 01

Logical sibling position becomes recycled slot number produces the wrong hierarchical widget state in a regression fixture.

Verified by executionVariant 1 · 6 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The virtual-siblings contract is violated at `r['index']+1` by replacing it with `d['slot']+1`.

VERIFIED REPAIR

Restore `r['index']+1` at this fault site while retaining the other tree state decisions.

Unsuccessful approach: The partial repair `r['index']` still violates a boundary or preservation case.

Case contract

Rows carry id,parent,logical sibling index,known sibling count,depth. The viewport must expose global sibling positions and counts, one-based depth, root ownership, expandable state only for branches, and stable identity independent of recycled slots.

Why this case matters

Offline executable model of a hierarchical accessibility interaction; inputs are bounded and valid as stipulated. No browser, assistive technology, or normative ARIA conformance is claimed.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(d):
    r=d['row']
    position=d['slot']+1
    size=r['count'] if r['known'] else -1
    level=r['depth']+1
    owner=r['parent'] if r['parent'] is not None else d['tree']
    expanded=r['open'] if r['branch'] else None
    selected=r['id'] in d['selected']
    active=r['id']==d['active']
    dom=d['tree']+':'+r['id']
    rowindex=d['offset']+d['slot']+1
    busy=r['loading'] and r['branch']
    return [position,size,level,owner,expanded,selected,active,dom,rowindex,busy]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = {1: [('branch', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 3, 'count': 9, 'known': True, 'depth': 1, 'open': True, 'branch': True, 'loading': True}, 'selected': ['b'], 'active': 'b', 'offset': 3, 'slot': 1, 'mounted': 3}, [4, 9, 2, 'p', True, True, True, 'tree:b', 5, True]), ('root', {'tree': 'tree', 'row': {'id': 'b', 'parent': None, 'index': 3, 'count': 9, 'known': True, 'depth': 1, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'x', 'offset': 3, 'slot': 1, 'mounted': 3}, [4, 9, 2, 'tree', True, False, False, 'tree:b', 5, True]), ('leaf', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 3, 'count': 9, 'known': True, 'depth': 1, 'open': True, 'branch': False, 'loading': True}, 'selected': ['b'], 'active': 'x', 'offset': 3, 'slot': 1, 'mounted': 3}, [4, 9, 2, 'p', None, True, False, 'tree:b', 5, False]), ('unknown', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 3, 'count': 9, 'known': False, 'depth': 1, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'b', 'offset': 3, 'slot': 1, 'mounted': 3}, [4, -1, 2, 'p', True, False, True, 'tree:b', 5, True]), ('idle', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 3, 'count': 9, 'known': True, 'depth': 1, 'open': True, 'branch': True, 'loading': False}, 'selected': ['x'], 'active': 'x', 'offset': 3, 'slot': 1, 'mounted': 3}, [4, 9, 2, 'p', True, False, False, 'tree:b', 5, False]), ('collapsed', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 0, 'count': 9, 'known': True, 'depth': 0, 'open': False, 'branch': True, 'loading': True}, 'selected': ['x'], 'active': 'b', 'offset': 3, 'slot': 1, 'mounted': 3}, [1, 9, 1, 'p', False, False, True, 'tree:b', 5, True])], 2: [('branch', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 4, 'count': 10, 'known': True, 'depth': 2, 'open': True, 'branch': True, 'loading': True}, 'selected': ['b'], 'active': 'b', 'offset': 6, 'slot': 1, 'mounted': 3}, [5, 10, 3, 'p', True, True, True, 'tree:b', 8, True]), ('root', {'tree': 'tree', 'row': {'id': 'b', 'parent': None, 'index': 4, 'count': 10, 'known': True, 'depth': 2, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'x', 'offset': 6, 'slot': 1, 'mounted': 3}, [5, 10, 3, 'tree', True, False, False, 'tree:b', 8, True]), ('leaf', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 4, 'count': 10, 'known': True, 'depth': 2, 'open': True, 'branch': False, 'loading': True}, 'selected': ['b'], 'active': 'x', 'offset': 6, 'slot': 1, 'mounted': 3}, [5, 10, 3, 'p', None, True, False, 'tree:b', 8, False]), ('unknown', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 4, 'count': 10, 'known': False, 'depth': 2, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'b', 'offset': 6, 'slot': 1, 'mounted': 3}, [5, -1, 3, 'p', True, False, True, 'tree:b', 8, True]), ('idle', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 4, 'count': 10, 'known': True, 'depth': 2, 'open': True, 'branch': True, 'loading': False}, 'selected': ['x'], 'active': 'x', 'offset': 6, 'slot': 1, 'mounted': 3}, [5, 10, 3, 'p', True, False, False, 'tree:b', 8, False]), ('collapsed', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 0, 'count': 10, 'known': True, 'depth': 0, 'open': False, 'branch': True, 'loading': True}, 'selected': ['x'], 'active': 'b', 'offset': 6, 'slot': 1, 'mounted': 3}, [1, 10, 1, 'p', False, False, True, 'tree:b', 8, True])], 3: [('branch', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 5, 'count': 11, 'known': True, 'depth': 3, 'open': True, 'branch': True, 'loading': True}, 'selected': ['b'], 'active': 'b', 'offset': 9, 'slot': 1, 'mounted': 3}, [6, 11, 4, 'p', True, True, True, 'tree:b', 11, True]), ('root', {'tree': 'tree', 'row': {'id': 'b', 'parent': None, 'index': 5, 'count': 11, 'known': True, 'depth': 3, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'x', 'offset': 9, 'slot': 1, 'mounted': 3}, [6, 11, 4, 'tree', True, False, False, 'tree:b', 11, True]), ('leaf', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 5, 'count': 11, 'known': True, 'depth': 3, 'open': True, 'branch': False, 'loading': True}, 'selected': ['b'], 'active': 'x', 'offset': 9, 'slot': 1, 'mounted': 3}, [6, 11, 4, 'p', None, True, False, 'tree:b', 11, False]), ('unknown', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 5, 'count': 11, 'known': False, 'depth': 3, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'b', 'offset': 9, 'slot': 1, 'mounted': 3}, [6, -1, 4, 'p', True, False, True, 'tree:b', 11, True]), ('idle', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 5, 'count': 11, 'known': True, 'depth': 3, 'open': True, 'branch': True, 'loading': False}, 'selected': ['x'], 'active': 'x', 'offset': 9, 'slot': 1, 'mounted': 3}, [6, 11, 4, 'p', True, False, False, 'tree:b', 11, False]), ('collapsed', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 0, 'count': 11, 'known': True, 'depth': 0, 'open': False, 'branch': True, 'loading': True}, 'selected': ['x'], 'active': 'b', 'offset': 9, 'slot': 1, 'mounted': 3}, [1, 11, 1, 'p', False, False, True, 'tree:b', 11, True])], 4: [('branch', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 6, 'count': 12, 'known': True, 'depth': 4, 'open': True, 'branch': True, 'loading': True}, 'selected': ['b'], 'active': 'b', 'offset': 12, 'slot': 1, 'mounted': 3}, [7, 12, 5, 'p', True, True, True, 'tree:b', 14, True]), ('root', {'tree': 'tree', 'row': {'id': 'b', 'parent': None, 'index': 6, 'count': 12, 'known': True, 'depth': 4, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'x', 'offset': 12, 'slot': 1, 'mounted': 3}, [7, 12, 5, 'tree', True, False, False, 'tree:b', 14, True]), ('leaf', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 6, 'count': 12, 'known': True, 'depth': 4, 'open': True, 'branch': False, 'loading': True}, 'selected': ['b'], 'active': 'x', 'offset': 12, 'slot': 1, 'mounted': 3}, [7, 12, 5, 'p', None, True, False, 'tree:b', 14, False]), ('unknown', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 6, 'count': 12, 'known': False, 'depth': 4, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'b', 'offset': 12, 'slot': 1, 'mounted': 3}, [7, -1, 5, 'p', True, False, True, 'tree:b', 14, True]), ('idle', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 6, 'count': 12, 'known': True, 'depth': 4, 'open': True, 'branch': True, 'loading': False}, 'selected': ['x'], 'active': 'x', 'offset': 12, 'slot': 1, 'mounted': 3}, [7, 12, 5, 'p', True, False, False, 'tree:b', 14, False]), ('collapsed', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 0, 'count': 12, 'known': True, 'depth': 0, 'open': False, 'branch': True, 'loading': True}, 'selected': ['x'], 'active': 'b', 'offset': 12, 'slot': 1, 'mounted': 3}, [1, 12, 1, 'p', False, False, True, 'tree:b', 14, True])], 5: [('branch', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 7, 'count': 13, 'known': True, 'depth': 5, 'open': True, 'branch': True, 'loading': True}, 'selected': ['b'], 'active': 'b', 'offset': 15, 'slot': 1, 'mounted': 3}, [8, 13, 6, 'p', True, True, True, 'tree:b', 17, True]), ('root', {'tree': 'tree', 'row': {'id': 'b', 'parent': None, 'index': 7, 'count': 13, 'known': True, 'depth': 5, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'x', 'offset': 15, 'slot': 1, 'mounted': 3}, [8, 13, 6, 'tree', True, False, False, 'tree:b', 17, True]), ('leaf', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 7, 'count': 13, 'known': True, 'depth': 5, 'open': True, 'branch': False, 'loading': True}, 'selected': ['b'], 'active': 'x', 'offset': 15, 'slot': 1, 'mounted': 3}, [8, 13, 6, 'p', None, True, False, 'tree:b', 17, False]), ('unknown', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 7, 'count': 13, 'known': False, 'depth': 5, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'b', 'offset': 15, 'slot': 1, 'mounted': 3}, [8, -1, 6, 'p', True, False, True, 'tree:b', 17, True]), ('idle', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 7, 'count': 13, 'known': True, 'depth': 5, 'open': True, 'branch': True, 'loading': False}, 'selected': ['x'], 'active': 'x', 'offset': 15, 'slot': 1, 'mounted': 3}, [8, 13, 6, 'p', True, False, False, 'tree:b', 17, False]), ('collapsed', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 0, 'count': 13, 'known': True, 'depth': 0, 'open': False, 'branch': True, 'loading': True}, 'selected': ['x'], 'active': 'b', 'offset': 15, 'slot': 1, 'mounted': 3}, [1, 13, 1, 'p', False, False, True, 'tree:b', 17, True])]}
for label, data, expected in cases[N]:
    check(label, solve(data), expected)
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 fixtureActualExpectedOutcome
branch[2, 9, 2, 'p', True, True, True, 'tree:b', 5, True][4, 9, 2, 'p', True, True, True, 'tree:b', 5, True]Failed
root[2, 9, 2, 'tree', True, False, False, 'tree:b', 5, True][4, 9, 2, 'tree', True, False, False, 'tree:b', 5, True]Failed
leaf[2, 9, 2, 'p', None, True, False, 'tree:b', 5, False][4, 9, 2, 'p', None, True, False, 'tree:b', 5, False]Failed
unknown[2, -1, 2, 'p', True, False, True, 'tree:b', 5, True][4, -1, 2, 'p', True, False, True, 'tree:b', 5, True]Failed
idle[2, 9, 2, 'p', True, False, False, 'tree:b', 5, False][4, 9, 2, 'p', True, False, False, 'tree:b', 5, False]Failed
collapsed[2, 9, 1, 'p', False, False, True, 'tree:b', 5, True][1, 9, 1, 'p', False, False, True, 'tree:b', 5, True]Failed

SHA-256 / 3c903e15837d12add53d3aec5de92983afc24dd4b1951f4aacbc5a98ff7e91df

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(d):
    r=d['row']
    position=r['index']
    size=r['count'] if r['known'] else -1
    level=r['depth']+1
    owner=r['parent'] if r['parent'] is not None else d['tree']
    expanded=r['open'] if r['branch'] else None
    selected=r['id'] in d['selected']
    active=r['id']==d['active']
    dom=d['tree']+':'+r['id']
    rowindex=d['offset']+d['slot']+1
    busy=r['loading'] and r['branch']
    return [position,size,level,owner,expanded,selected,active,dom,rowindex,busy]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = {1: [('branch', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 3, 'count': 9, 'known': True, 'depth': 1, 'open': True, 'branch': True, 'loading': True}, 'selected': ['b'], 'active': 'b', 'offset': 3, 'slot': 1, 'mounted': 3}, [4, 9, 2, 'p', True, True, True, 'tree:b', 5, True]), ('root', {'tree': 'tree', 'row': {'id': 'b', 'parent': None, 'index': 3, 'count': 9, 'known': True, 'depth': 1, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'x', 'offset': 3, 'slot': 1, 'mounted': 3}, [4, 9, 2, 'tree', True, False, False, 'tree:b', 5, True]), ('leaf', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 3, 'count': 9, 'known': True, 'depth': 1, 'open': True, 'branch': False, 'loading': True}, 'selected': ['b'], 'active': 'x', 'offset': 3, 'slot': 1, 'mounted': 3}, [4, 9, 2, 'p', None, True, False, 'tree:b', 5, False]), ('unknown', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 3, 'count': 9, 'known': False, 'depth': 1, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'b', 'offset': 3, 'slot': 1, 'mounted': 3}, [4, -1, 2, 'p', True, False, True, 'tree:b', 5, True]), ('idle', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 3, 'count': 9, 'known': True, 'depth': 1, 'open': True, 'branch': True, 'loading': False}, 'selected': ['x'], 'active': 'x', 'offset': 3, 'slot': 1, 'mounted': 3}, [4, 9, 2, 'p', True, False, False, 'tree:b', 5, False]), ('collapsed', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 0, 'count': 9, 'known': True, 'depth': 0, 'open': False, 'branch': True, 'loading': True}, 'selected': ['x'], 'active': 'b', 'offset': 3, 'slot': 1, 'mounted': 3}, [1, 9, 1, 'p', False, False, True, 'tree:b', 5, True])], 2: [('branch', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 4, 'count': 10, 'known': True, 'depth': 2, 'open': True, 'branch': True, 'loading': True}, 'selected': ['b'], 'active': 'b', 'offset': 6, 'slot': 1, 'mounted': 3}, [5, 10, 3, 'p', True, True, True, 'tree:b', 8, True]), ('root', {'tree': 'tree', 'row': {'id': 'b', 'parent': None, 'index': 4, 'count': 10, 'known': True, 'depth': 2, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'x', 'offset': 6, 'slot': 1, 'mounted': 3}, [5, 10, 3, 'tree', True, False, False, 'tree:b', 8, True]), ('leaf', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 4, 'count': 10, 'known': True, 'depth': 2, 'open': True, 'branch': False, 'loading': True}, 'selected': ['b'], 'active': 'x', 'offset': 6, 'slot': 1, 'mounted': 3}, [5, 10, 3, 'p', None, True, False, 'tree:b', 8, False]), ('unknown', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 4, 'count': 10, 'known': False, 'depth': 2, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'b', 'offset': 6, 'slot': 1, 'mounted': 3}, [5, -1, 3, 'p', True, False, True, 'tree:b', 8, True]), ('idle', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 4, 'count': 10, 'known': True, 'depth': 2, 'open': True, 'branch': True, 'loading': False}, 'selected': ['x'], 'active': 'x', 'offset': 6, 'slot': 1, 'mounted': 3}, [5, 10, 3, 'p', True, False, False, 'tree:b', 8, False]), ('collapsed', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 0, 'count': 10, 'known': True, 'depth': 0, 'open': False, 'branch': True, 'loading': True}, 'selected': ['x'], 'active': 'b', 'offset': 6, 'slot': 1, 'mounted': 3}, [1, 10, 1, 'p', False, False, True, 'tree:b', 8, True])], 3: [('branch', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 5, 'count': 11, 'known': True, 'depth': 3, 'open': True, 'branch': True, 'loading': True}, 'selected': ['b'], 'active': 'b', 'offset': 9, 'slot': 1, 'mounted': 3}, [6, 11, 4, 'p', True, True, True, 'tree:b', 11, True]), ('root', {'tree': 'tree', 'row': {'id': 'b', 'parent': None, 'index': 5, 'count': 11, 'known': True, 'depth': 3, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'x', 'offset': 9, 'slot': 1, 'mounted': 3}, [6, 11, 4, 'tree', True, False, False, 'tree:b', 11, True]), ('leaf', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 5, 'count': 11, 'known': True, 'depth': 3, 'open': True, 'branch': False, 'loading': True}, 'selected': ['b'], 'active': 'x', 'offset': 9, 'slot': 1, 'mounted': 3}, [6, 11, 4, 'p', None, True, False, 'tree:b', 11, False]), ('unknown', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 5, 'count': 11, 'known': False, 'depth': 3, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'b', 'offset': 9, 'slot': 1, 'mounted': 3}, [6, -1, 4, 'p', True, False, True, 'tree:b', 11, True]), ('idle', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 5, 'count': 11, 'known': True, 'depth': 3, 'open': True, 'branch': True, 'loading': False}, 'selected': ['x'], 'active': 'x', 'offset': 9, 'slot': 1, 'mounted': 3}, [6, 11, 4, 'p', True, False, False, 'tree:b', 11, False]), ('collapsed', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 0, 'count': 11, 'known': True, 'depth': 0, 'open': False, 'branch': True, 'loading': True}, 'selected': ['x'], 'active': 'b', 'offset': 9, 'slot': 1, 'mounted': 3}, [1, 11, 1, 'p', False, False, True, 'tree:b', 11, True])], 4: [('branch', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 6, 'count': 12, 'known': True, 'depth': 4, 'open': True, 'branch': True, 'loading': True}, 'selected': ['b'], 'active': 'b', 'offset': 12, 'slot': 1, 'mounted': 3}, [7, 12, 5, 'p', True, True, True, 'tree:b', 14, True]), ('root', {'tree': 'tree', 'row': {'id': 'b', 'parent': None, 'index': 6, 'count': 12, 'known': True, 'depth': 4, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'x', 'offset': 12, 'slot': 1, 'mounted': 3}, [7, 12, 5, 'tree', True, False, False, 'tree:b', 14, True]), ('leaf', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 6, 'count': 12, 'known': True, 'depth': 4, 'open': True, 'branch': False, 'loading': True}, 'selected': ['b'], 'active': 'x', 'offset': 12, 'slot': 1, 'mounted': 3}, [7, 12, 5, 'p', None, True, False, 'tree:b', 14, False]), ('unknown', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 6, 'count': 12, 'known': False, 'depth': 4, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'b', 'offset': 12, 'slot': 1, 'mounted': 3}, [7, -1, 5, 'p', True, False, True, 'tree:b', 14, True]), ('idle', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 6, 'count': 12, 'known': True, 'depth': 4, 'open': True, 'branch': True, 'loading': False}, 'selected': ['x'], 'active': 'x', 'offset': 12, 'slot': 1, 'mounted': 3}, [7, 12, 5, 'p', True, False, False, 'tree:b', 14, False]), ('collapsed', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 0, 'count': 12, 'known': True, 'depth': 0, 'open': False, 'branch': True, 'loading': True}, 'selected': ['x'], 'active': 'b', 'offset': 12, 'slot': 1, 'mounted': 3}, [1, 12, 1, 'p', False, False, True, 'tree:b', 14, True])], 5: [('branch', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 7, 'count': 13, 'known': True, 'depth': 5, 'open': True, 'branch': True, 'loading': True}, 'selected': ['b'], 'active': 'b', 'offset': 15, 'slot': 1, 'mounted': 3}, [8, 13, 6, 'p', True, True, True, 'tree:b', 17, True]), ('root', {'tree': 'tree', 'row': {'id': 'b', 'parent': None, 'index': 7, 'count': 13, 'known': True, 'depth': 5, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'x', 'offset': 15, 'slot': 1, 'mounted': 3}, [8, 13, 6, 'tree', True, False, False, 'tree:b', 17, True]), ('leaf', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 7, 'count': 13, 'known': True, 'depth': 5, 'open': True, 'branch': False, 'loading': True}, 'selected': ['b'], 'active': 'x', 'offset': 15, 'slot': 1, 'mounted': 3}, [8, 13, 6, 'p', None, True, False, 'tree:b', 17, False]), ('unknown', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 7, 'count': 13, 'known': False, 'depth': 5, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'b', 'offset': 15, 'slot': 1, 'mounted': 3}, [8, -1, 6, 'p', True, False, True, 'tree:b', 17, True]), ('idle', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 7, 'count': 13, 'known': True, 'depth': 5, 'open': True, 'branch': True, 'loading': False}, 'selected': ['x'], 'active': 'x', 'offset': 15, 'slot': 1, 'mounted': 3}, [8, 13, 6, 'p', True, False, False, 'tree:b', 17, False]), ('collapsed', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 0, 'count': 13, 'known': True, 'depth': 0, 'open': False, 'branch': True, 'loading': True}, 'selected': ['x'], 'active': 'b', 'offset': 15, 'slot': 1, 'mounted': 3}, [1, 13, 1, 'p', False, False, True, 'tree:b', 17, True])]}
for label, data, expected in cases[N]:
    check(label, solve(data), expected)
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 fixtureActualExpectedOutcome
branch[3, 9, 2, 'p', True, True, True, 'tree:b', 5, True][4, 9, 2, 'p', True, True, True, 'tree:b', 5, True]Failed
root[3, 9, 2, 'tree', True, False, False, 'tree:b', 5, True][4, 9, 2, 'tree', True, False, False, 'tree:b', 5, True]Failed
leaf[3, 9, 2, 'p', None, True, False, 'tree:b', 5, False][4, 9, 2, 'p', None, True, False, 'tree:b', 5, False]Failed
unknown[3, -1, 2, 'p', True, False, True, 'tree:b', 5, True][4, -1, 2, 'p', True, False, True, 'tree:b', 5, True]Failed
idle[3, 9, 2, 'p', True, False, False, 'tree:b', 5, False][4, 9, 2, 'p', True, False, False, 'tree:b', 5, False]Failed
collapsed[0, 9, 1, 'p', False, False, True, 'tree:b', 5, True][1, 9, 1, 'p', False, False, True, 'tree:b', 5, True]Failed

SHA-256 / 147fea80720805734adbf91a59c7e414fd50c0fdd01b2acd5e4eb9a8d9e6897a

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(d):
    r=d['row']
    position=r['index']+1
    size=r['count'] if r['known'] else -1
    level=r['depth']+1
    owner=r['parent'] if r['parent'] is not None else d['tree']
    expanded=r['open'] if r['branch'] else None
    selected=r['id'] in d['selected']
    active=r['id']==d['active']
    dom=d['tree']+':'+r['id']
    rowindex=d['offset']+d['slot']+1
    busy=r['loading'] and r['branch']
    return [position,size,level,owner,expanded,selected,active,dom,rowindex,busy]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = {1: [('branch', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 3, 'count': 9, 'known': True, 'depth': 1, 'open': True, 'branch': True, 'loading': True}, 'selected': ['b'], 'active': 'b', 'offset': 3, 'slot': 1, 'mounted': 3}, [4, 9, 2, 'p', True, True, True, 'tree:b', 5, True]), ('root', {'tree': 'tree', 'row': {'id': 'b', 'parent': None, 'index': 3, 'count': 9, 'known': True, 'depth': 1, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'x', 'offset': 3, 'slot': 1, 'mounted': 3}, [4, 9, 2, 'tree', True, False, False, 'tree:b', 5, True]), ('leaf', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 3, 'count': 9, 'known': True, 'depth': 1, 'open': True, 'branch': False, 'loading': True}, 'selected': ['b'], 'active': 'x', 'offset': 3, 'slot': 1, 'mounted': 3}, [4, 9, 2, 'p', None, True, False, 'tree:b', 5, False]), ('unknown', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 3, 'count': 9, 'known': False, 'depth': 1, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'b', 'offset': 3, 'slot': 1, 'mounted': 3}, [4, -1, 2, 'p', True, False, True, 'tree:b', 5, True]), ('idle', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 3, 'count': 9, 'known': True, 'depth': 1, 'open': True, 'branch': True, 'loading': False}, 'selected': ['x'], 'active': 'x', 'offset': 3, 'slot': 1, 'mounted': 3}, [4, 9, 2, 'p', True, False, False, 'tree:b', 5, False]), ('collapsed', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 0, 'count': 9, 'known': True, 'depth': 0, 'open': False, 'branch': True, 'loading': True}, 'selected': ['x'], 'active': 'b', 'offset': 3, 'slot': 1, 'mounted': 3}, [1, 9, 1, 'p', False, False, True, 'tree:b', 5, True])], 2: [('branch', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 4, 'count': 10, 'known': True, 'depth': 2, 'open': True, 'branch': True, 'loading': True}, 'selected': ['b'], 'active': 'b', 'offset': 6, 'slot': 1, 'mounted': 3}, [5, 10, 3, 'p', True, True, True, 'tree:b', 8, True]), ('root', {'tree': 'tree', 'row': {'id': 'b', 'parent': None, 'index': 4, 'count': 10, 'known': True, 'depth': 2, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'x', 'offset': 6, 'slot': 1, 'mounted': 3}, [5, 10, 3, 'tree', True, False, False, 'tree:b', 8, True]), ('leaf', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 4, 'count': 10, 'known': True, 'depth': 2, 'open': True, 'branch': False, 'loading': True}, 'selected': ['b'], 'active': 'x', 'offset': 6, 'slot': 1, 'mounted': 3}, [5, 10, 3, 'p', None, True, False, 'tree:b', 8, False]), ('unknown', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 4, 'count': 10, 'known': False, 'depth': 2, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'b', 'offset': 6, 'slot': 1, 'mounted': 3}, [5, -1, 3, 'p', True, False, True, 'tree:b', 8, True]), ('idle', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 4, 'count': 10, 'known': True, 'depth': 2, 'open': True, 'branch': True, 'loading': False}, 'selected': ['x'], 'active': 'x', 'offset': 6, 'slot': 1, 'mounted': 3}, [5, 10, 3, 'p', True, False, False, 'tree:b', 8, False]), ('collapsed', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 0, 'count': 10, 'known': True, 'depth': 0, 'open': False, 'branch': True, 'loading': True}, 'selected': ['x'], 'active': 'b', 'offset': 6, 'slot': 1, 'mounted': 3}, [1, 10, 1, 'p', False, False, True, 'tree:b', 8, True])], 3: [('branch', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 5, 'count': 11, 'known': True, 'depth': 3, 'open': True, 'branch': True, 'loading': True}, 'selected': ['b'], 'active': 'b', 'offset': 9, 'slot': 1, 'mounted': 3}, [6, 11, 4, 'p', True, True, True, 'tree:b', 11, True]), ('root', {'tree': 'tree', 'row': {'id': 'b', 'parent': None, 'index': 5, 'count': 11, 'known': True, 'depth': 3, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'x', 'offset': 9, 'slot': 1, 'mounted': 3}, [6, 11, 4, 'tree', True, False, False, 'tree:b', 11, True]), ('leaf', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 5, 'count': 11, 'known': True, 'depth': 3, 'open': True, 'branch': False, 'loading': True}, 'selected': ['b'], 'active': 'x', 'offset': 9, 'slot': 1, 'mounted': 3}, [6, 11, 4, 'p', None, True, False, 'tree:b', 11, False]), ('unknown', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 5, 'count': 11, 'known': False, 'depth': 3, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'b', 'offset': 9, 'slot': 1, 'mounted': 3}, [6, -1, 4, 'p', True, False, True, 'tree:b', 11, True]), ('idle', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 5, 'count': 11, 'known': True, 'depth': 3, 'open': True, 'branch': True, 'loading': False}, 'selected': ['x'], 'active': 'x', 'offset': 9, 'slot': 1, 'mounted': 3}, [6, 11, 4, 'p', True, False, False, 'tree:b', 11, False]), ('collapsed', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 0, 'count': 11, 'known': True, 'depth': 0, 'open': False, 'branch': True, 'loading': True}, 'selected': ['x'], 'active': 'b', 'offset': 9, 'slot': 1, 'mounted': 3}, [1, 11, 1, 'p', False, False, True, 'tree:b', 11, True])], 4: [('branch', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 6, 'count': 12, 'known': True, 'depth': 4, 'open': True, 'branch': True, 'loading': True}, 'selected': ['b'], 'active': 'b', 'offset': 12, 'slot': 1, 'mounted': 3}, [7, 12, 5, 'p', True, True, True, 'tree:b', 14, True]), ('root', {'tree': 'tree', 'row': {'id': 'b', 'parent': None, 'index': 6, 'count': 12, 'known': True, 'depth': 4, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'x', 'offset': 12, 'slot': 1, 'mounted': 3}, [7, 12, 5, 'tree', True, False, False, 'tree:b', 14, True]), ('leaf', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 6, 'count': 12, 'known': True, 'depth': 4, 'open': True, 'branch': False, 'loading': True}, 'selected': ['b'], 'active': 'x', 'offset': 12, 'slot': 1, 'mounted': 3}, [7, 12, 5, 'p', None, True, False, 'tree:b', 14, False]), ('unknown', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 6, 'count': 12, 'known': False, 'depth': 4, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'b', 'offset': 12, 'slot': 1, 'mounted': 3}, [7, -1, 5, 'p', True, False, True, 'tree:b', 14, True]), ('idle', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 6, 'count': 12, 'known': True, 'depth': 4, 'open': True, 'branch': True, 'loading': False}, 'selected': ['x'], 'active': 'x', 'offset': 12, 'slot': 1, 'mounted': 3}, [7, 12, 5, 'p', True, False, False, 'tree:b', 14, False]), ('collapsed', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 0, 'count': 12, 'known': True, 'depth': 0, 'open': False, 'branch': True, 'loading': True}, 'selected': ['x'], 'active': 'b', 'offset': 12, 'slot': 1, 'mounted': 3}, [1, 12, 1, 'p', False, False, True, 'tree:b', 14, True])], 5: [('branch', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 7, 'count': 13, 'known': True, 'depth': 5, 'open': True, 'branch': True, 'loading': True}, 'selected': ['b'], 'active': 'b', 'offset': 15, 'slot': 1, 'mounted': 3}, [8, 13, 6, 'p', True, True, True, 'tree:b', 17, True]), ('root', {'tree': 'tree', 'row': {'id': 'b', 'parent': None, 'index': 7, 'count': 13, 'known': True, 'depth': 5, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'x', 'offset': 15, 'slot': 1, 'mounted': 3}, [8, 13, 6, 'tree', True, False, False, 'tree:b', 17, True]), ('leaf', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 7, 'count': 13, 'known': True, 'depth': 5, 'open': True, 'branch': False, 'loading': True}, 'selected': ['b'], 'active': 'x', 'offset': 15, 'slot': 1, 'mounted': 3}, [8, 13, 6, 'p', None, True, False, 'tree:b', 17, False]), ('unknown', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 7, 'count': 13, 'known': False, 'depth': 5, 'open': True, 'branch': True, 'loading': True}, 'selected': [], 'active': 'b', 'offset': 15, 'slot': 1, 'mounted': 3}, [8, -1, 6, 'p', True, False, True, 'tree:b', 17, True]), ('idle', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 7, 'count': 13, 'known': True, 'depth': 5, 'open': True, 'branch': True, 'loading': False}, 'selected': ['x'], 'active': 'x', 'offset': 15, 'slot': 1, 'mounted': 3}, [8, 13, 6, 'p', True, False, False, 'tree:b', 17, False]), ('collapsed', {'tree': 'tree', 'row': {'id': 'b', 'parent': 'p', 'index': 0, 'count': 13, 'known': True, 'depth': 0, 'open': False, 'branch': True, 'loading': True}, 'selected': ['x'], 'active': 'b', 'offset': 15, 'slot': 1, 'mounted': 3}, [1, 13, 1, 'p', False, False, True, 'tree:b', 17, True])]}
for label, data, expected in cases[N]:
    check(label, solve(data), expected)
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 fixtureActualExpectedOutcome
branch[4, 9, 2, 'p', True, True, True, 'tree:b', 5, True][4, 9, 2, 'p', True, True, True, 'tree:b', 5, True]Passed
root[4, 9, 2, 'tree', True, False, False, 'tree:b', 5, True][4, 9, 2, 'tree', True, False, False, 'tree:b', 5, True]Passed
leaf[4, 9, 2, 'p', None, True, False, 'tree:b', 5, False][4, 9, 2, 'p', None, True, False, 'tree:b', 5, False]Passed
unknown[4, -1, 2, 'p', True, False, True, 'tree:b', 5, True][4, -1, 2, 'p', True, False, True, 'tree:b', 5, True]Passed
idle[4, 9, 2, 'p', True, False, False, 'tree:b', 5, False][4, 9, 2, 'p', True, False, False, 'tree:b', 5, False]Passed
collapsed[1, 9, 1, 'p', False, False, True, 'tree:b', 5, True][1, 9, 1, 'p', False, False, True, 'tree:b', 5, True]Passed

SHA-256 / 8a7c5659a01e6fcc2cd5cca0b54a3acdce82bd94e06241cd0d806e814972c35a

Verification & scope

Synthetic deterministic hierarchical-widget data contract; not an implementation of a browser accessibility tree. 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 2026-09-29T14:43:11.267344+00:00.

Case digest / 6b3931ebbc7d001c4b1c875239be17853d0fc9f3b75969ce58795c7b2dba39bb