FA-53981 / Accessibility interaction semantics / Open access
Nontext semantic values enter the string property bridge · case 01
Nontext semantic values enter the string property bridge.
ROOT CAUSE
The value type decision in the property patch adapter violates its declared contract.
THE FAILURE
The value type decision in the property patch adapter violates its declared contract.
Unsuccessful approach: The local repair substitutes all(v is None or isinstance(v,(str,int)) for v in changes.values()) but still mishandles the regression fixtures.
Case contract
Input [initial,revision,updates]. Updates [base_revision,next_revision,changes] apply atomically only if base matches current and next is greater; updates cannot change immutable id or role. Allowed dynamic keys name,description,value,help,language; unknown keys reject whole update. None deletes a property, empty string is retained; values must be strings or None. Return [state,revision,accepted_flags]. Copy initial. Revision advances even for no-op changes.
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):
initial,revision,updates = data
state = dict(initial)
accepted = []
for base,nxt,changes in updates:
valid = base == revision and nxt > base
valid = valid and all(k in {'name','description','value','help','language'} for k in changes)
valid = valid and True
accepted.append(valid)
if not valid: continue
for key,value in changes.items():
if value is None: state.pop(key,None)
else: state[key] = value
revision = nxt
return [state,revision,accepted]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('contract fixture 1', solve([{'id':'x','role':'image','name':'old'},N,[[N,N+1,{'name':'new','help':''}],[N,N+2,{'name':'stale'}]]],), [{'id':'x','role':'image','name':'new','help':''},N+1,[True,False]])
check('contract fixture 2', solve([{'name':'x','help':'h'},N,[[N,N+1,{'name':None}],[N+1,N+2,{'absent':'bad','help':'bad'}]]],), [{'help':'h'},N+1,[True,False]])
check('contract fixture 3', solve([{'id':'x','role':'image'},N,[[N,N+1,{'id':'y'}],[N,N+1,{'role':'button'}]]],), [{'id':'x','role':'image'},N,[False,False]])
check('contract fixture 4', solve([{},N,[[N,N,{'name':'bad'}],[N,N-1,{}],[N,N+1,{}]]],), [{},N+1,[False,False,True]])
check('contract fixture 5', solve([{'name':'x'},N,[[N,N+1,{'name':42,'help':'partial'}]]],), [{'name':'x'},N,[False]])
check('contract fixture 6', solve([{},N,[[N,N+1,{'name':None,'description':'D','value':'0','language':'en'}]]],), [{'description':'D','value':'0','language':'en'},N+1,[True]])
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 |
|---|---|---|---|
| contract fixture 1 | [{'help': '', 'id': 'x', 'name': 'new', 'role': 'image'}, 2, [True, False]] | [{'help': '', 'id': 'x', 'name': 'new', 'role': 'image'}, 2, [True, False]] | Passed |
| contract fixture 2 | [{'help': 'h'}, 2, [True, False]] | [{'help': 'h'}, 2, [True, False]] | Passed |
| contract fixture 3 | [{'id': 'x', 'role': 'image'}, 1, [False, False]] | [{'id': 'x', 'role': 'image'}, 1, [False, False]] | Passed |
| contract fixture 4 | [{}, 2, [False, False, True]] | [{}, 2, [False, False, True]] | Passed |
| contract fixture 5 | [{'help': 'partial', 'name': 42}, 2, [True]] | [{'name': 'x'}, 1, [False]] | Failed |
| contract fixture 6 | [{'description': 'D', 'language': 'en', 'value': '0'}, 2, [True]] | [{'description': 'D', 'language': 'en', 'value': '0'}, 2, [True]] | Passed |
SHA-256 / 1a7b71ec63b2dbd0f5e53085707f3f41cf5017e87ebdc3013c63081ee90b6c05
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(data):
initial,revision,updates = data
state = dict(initial)
accepted = []
for base,nxt,changes in updates:
valid = base == revision and nxt > base
valid = valid and all(k in {'name','description','value','help','language'} for k in changes)
valid = valid and all(v is None or isinstance(v,(str,int)) for v in changes.values())
accepted.append(valid)
if not valid: continue
for key,value in changes.items():
if value is None: state.pop(key,None)
else: state[key] = value
revision = nxt
return [state,revision,accepted]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('contract fixture 1', solve([{'id':'x','role':'image','name':'old'},N,[[N,N+1,{'name':'new','help':''}],[N,N+2,{'name':'stale'}]]],), [{'id':'x','role':'image','name':'new','help':''},N+1,[True,False]])
check('contract fixture 2', solve([{'name':'x','help':'h'},N,[[N,N+1,{'name':None}],[N+1,N+2,{'absent':'bad','help':'bad'}]]],), [{'help':'h'},N+1,[True,False]])
check('contract fixture 3', solve([{'id':'x','role':'image'},N,[[N,N+1,{'id':'y'}],[N,N+1,{'role':'button'}]]],), [{'id':'x','role':'image'},N,[False,False]])
check('contract fixture 4', solve([{},N,[[N,N,{'name':'bad'}],[N,N-1,{}],[N,N+1,{}]]],), [{},N+1,[False,False,True]])
check('contract fixture 5', solve([{'name':'x'},N,[[N,N+1,{'name':42,'help':'partial'}]]],), [{'name':'x'},N,[False]])
check('contract fixture 6', solve([{},N,[[N,N+1,{'name':None,'description':'D','value':'0','language':'en'}]]],), [{'description':'D','value':'0','language':'en'},N+1,[True]])
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 |
|---|---|---|---|
| contract fixture 1 | [{'help': '', 'id': 'x', 'name': 'new', 'role': 'image'}, 2, [True, False]] | [{'help': '', 'id': 'x', 'name': 'new', 'role': 'image'}, 2, [True, False]] | Passed |
| contract fixture 2 | [{'help': 'h'}, 2, [True, False]] | [{'help': 'h'}, 2, [True, False]] | Passed |
| contract fixture 3 | [{'id': 'x', 'role': 'image'}, 1, [False, False]] | [{'id': 'x', 'role': 'image'}, 1, [False, False]] | Passed |
| contract fixture 4 | [{}, 2, [False, False, True]] | [{}, 2, [False, False, True]] | Passed |
| contract fixture 5 | [{'help': 'partial', 'name': 42}, 2, [True]] | [{'name': 'x'}, 1, [False]] | Failed |
| contract fixture 6 | [{'description': 'D', 'language': 'en', 'value': '0'}, 2, [True]] | [{'description': 'D', 'language': 'en', 'value': '0'}, 2, [True]] | Passed |
SHA-256 / 0806092b4c08df87fda446bf43be4104fd9731b24aba9c152e0eb66ce0344707
HELD IN THE MEMBER ARCHIVE
The verified repair and its recorded checks are member-only.
This mechanism has 6 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.
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Sign in to the archive ↗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 2026-09-29T14:45:44.317336+00:00.
Case digest / 2957a7002136943ff2edd863fba0a342c794ba0a569d3eb8cd91185aff6d8667