FAILURE MAP
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FA-54336 / Accessibility interaction semantics / Open access

Move records contain the departed parent · case 01

Move records contain the departed parent.

Verified by executionVariant 1 · 7 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The move destination decision in the snapshot delta adapter violates its declared contract.

THE FAILURE

The move destination decision in the snapshot delta adapter violates its declared contract.

Unsuccessful approach: The local repair substitutes ['move',ident,None,new['order']] but still mishandles the regression fixtures.

Case contract

Input [before,after] maps stable object ID to {role,name,parent,order}. Return delta operations in phases: removed IDs sorted lexical; added IDs sorted by after order then ID; common IDs sorted lexical get role-replace if role differs, otherwise name-set if name differs; parent/order changes append move even after role-replace. Removed values use old role, added records preserve complete new record, name-set preserves empty names. Same ID is never remove+add just for role changes. Return operations lists.

Why this case matters

Offline accessibility bridge model with explicit policy; useful for testing semantic API adapters independently of browser implementations.

1 / The failure

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

N = 1
observations = []
def solve(data):
    before,after = data
    result = []
    for ident in sorted(set(before)-set(after)): result.append(['remove',ident,before[ident]['role']])
    for ident in sorted(set(after)-set(before),key=lambda x:(after[x]['order'],x)): result.append(['add',ident,after[ident]])
    for ident in sorted(set(before)&set(after)):
        old,new = before[ident],after[ident]
        if old['role'] != new['role']: result.append(['replace-role',ident,new['role']])
        elif old['name'] != new['name']: result.append(['set-name',ident,new['name']])
        if old['parent'] != new['parent'] or old['order'] != new['order']: result.append(['move',ident,old['parent'],new['order']])
    return result
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('contract fixture 1', solve([{'x':{'role':'image','name':'old','parent':'a','order':N}},{'x':{'role':'button','name':'new','parent':'b','order':N+1}}],), [['replace-role','x','button'],['move','x','b',N+1]])
check('contract fixture 2', solve([{'x':{'role':'image','name':'old','parent':None,'order':0}},{'x':{'role':'image','name':'','parent':None,'order':0}}],), [['set-name','x','']])
check('contract fixture 3', solve([{'z':{'role':'image','name':'Z','parent':None,'order':0},'a':{'role':'group','name':'A','parent':None,'order':1}},{}],), [['remove','a','group'],['remove','z','image']])
check('contract fixture 4', solve([{}, {'z':{'role':'image','name':'Z','parent':None,'order':0},'a':{'role':'group','name':'A','parent':None,'order':1}}],), [['add','z',{'role':'image','name':'Z','parent':None,'order':0}],['add','a',{'role':'group','name':'A','parent':None,'order':1}]])
check('contract fixture 5', solve([{'x':{'role':'image','name':'X','parent':'a','order':0}},{'x':{'role':'image','name':'X','parent':'a','order':N}}],), [['move','x','a',N]])
check('contract fixture 6', solve([{'x':{'role':'image','name':'X','parent':'a','order':0}},{'x':{'role':'image','name':'X','parent':'b','order':0}}],), [['move','x','b',0]])
check('contract fixture 7', solve([{},{}],), [])
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
contract fixture 1[['replace-role', 'x', 'button'], ['move', 'x', 'a', 2]][['replace-role', 'x', 'button'], ['move', 'x', 'b', 2]]Failed
contract fixture 2[['set-name', 'x', '']][['set-name', 'x', '']]Passed
contract fixture 3[['remove', 'a', 'group'], ['remove', 'z', 'image']][['remove', 'a', 'group'], ['remove', 'z', 'image']]Passed
contract fixture 4[['add', 'z', {'name': 'Z', 'order': 0, 'parent': None, 'role': 'image'}], ['add', 'a', {'name': 'A', 'order': 1, 'parent': None, 'role': 'group'}]][['add', 'z', {'name': 'Z', 'order': 0, 'parent': None, 'role': 'image'}], ['add', 'a', {'name': 'A', 'order': 1, 'parent': None, 'role': 'group'}]]Passed
contract fixture 5[['move', 'x', 'a', 1]][['move', 'x', 'a', 1]]Passed
contract fixture 6[['move', 'x', 'a', 0]][['move', 'x', 'b', 0]]Failed
contract fixture 7[][]Passed

SHA-256 / 0f9863be9089811292f7e6d68bde8efceb94cfc890a1e8171e7819c37b8d7ed8

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(data):
    before,after = data
    result = []
    for ident in sorted(set(before)-set(after)): result.append(['remove',ident,before[ident]['role']])
    for ident in sorted(set(after)-set(before),key=lambda x:(after[x]['order'],x)): result.append(['add',ident,after[ident]])
    for ident in sorted(set(before)&set(after)):
        old,new = before[ident],after[ident]
        if old['role'] != new['role']: result.append(['replace-role',ident,new['role']])
        elif old['name'] != new['name']: result.append(['set-name',ident,new['name']])
        if old['parent'] != new['parent'] or old['order'] != new['order']: result.append(['move',ident,None,new['order']])
    return result
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('contract fixture 1', solve([{'x':{'role':'image','name':'old','parent':'a','order':N}},{'x':{'role':'button','name':'new','parent':'b','order':N+1}}],), [['replace-role','x','button'],['move','x','b',N+1]])
check('contract fixture 2', solve([{'x':{'role':'image','name':'old','parent':None,'order':0}},{'x':{'role':'image','name':'','parent':None,'order':0}}],), [['set-name','x','']])
check('contract fixture 3', solve([{'z':{'role':'image','name':'Z','parent':None,'order':0},'a':{'role':'group','name':'A','parent':None,'order':1}},{}],), [['remove','a','group'],['remove','z','image']])
check('contract fixture 4', solve([{}, {'z':{'role':'image','name':'Z','parent':None,'order':0},'a':{'role':'group','name':'A','parent':None,'order':1}}],), [['add','z',{'role':'image','name':'Z','parent':None,'order':0}],['add','a',{'role':'group','name':'A','parent':None,'order':1}]])
check('contract fixture 5', solve([{'x':{'role':'image','name':'X','parent':'a','order':0}},{'x':{'role':'image','name':'X','parent':'a','order':N}}],), [['move','x','a',N]])
check('contract fixture 6', solve([{'x':{'role':'image','name':'X','parent':'a','order':0}},{'x':{'role':'image','name':'X','parent':'b','order':0}}],), [['move','x','b',0]])
check('contract fixture 7', solve([{},{}],), [])
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
contract fixture 1[['replace-role', 'x', 'button'], ['move', 'x', None, 2]][['replace-role', 'x', 'button'], ['move', 'x', 'b', 2]]Failed
contract fixture 2[['set-name', 'x', '']][['set-name', 'x', '']]Passed
contract fixture 3[['remove', 'a', 'group'], ['remove', 'z', 'image']][['remove', 'a', 'group'], ['remove', 'z', 'image']]Passed
contract fixture 4[['add', 'z', {'name': 'Z', 'order': 0, 'parent': None, 'role': 'image'}], ['add', 'a', {'name': 'A', 'order': 1, 'parent': None, 'role': 'group'}]][['add', 'z', {'name': 'Z', 'order': 0, 'parent': None, 'role': 'image'}], ['add', 'a', {'name': 'A', 'order': 1, 'parent': None, 'role': 'group'}]]Passed
contract fixture 5[['move', 'x', None, 1]][['move', 'x', 'a', 1]]Failed
contract fixture 6[['move', 'x', None, 0]][['move', 'x', 'b', 0]]Failed
contract fixture 7[][]Passed

SHA-256 / eb9159c94f04c7942a9d0bb5621aa6e4c9fd6a158395f10852298b6feb39b3fb

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 7 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.

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Verification & scope

Stipulated finite adapter contract, not a claim of platform accessibility or ARIA conformance. 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 2026-09-29T14:45:47.427179+00:00.

Case digest / 48bffd8bf379b2e956761211d1049a1526d189d129c8fac489b5782ef37c8c08