FA-54471 / Accessibility interaction semantics / Open access

Name dependency traversal stops at uncached providers · case 01

Name dependency traversal stops at uncached providers.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The uncached provider decision in the name dependencies adapter violates its declared contract.

THE FAILURE

The uncached provider decision in the name dependencies adapter violates its declared contract.

Unsuccessful approach: The local repair substitutes if node in seen or not cache.get(node): continue but still mishandles the regression fixtures.

Case contract

Input [cached_names,dependencies,mutations]. Dependencies [consumer,provider,channel] with channel name or description; only name affects cached names. Mutation [provider,kind] kind text,remove,style,unrelated; text/remove invalidate provider and all transitively dependent name consumers, style invalidates provider only, unrelated does nothing. Include only cached IDs in returned invalidated list but traverse uncached providers. Ignore cycles safely, preserve cache dictionary order in final result. Return [remaining_cache,invalidated_ids].

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):
    cache,dependencies,mutations = data
    reverse = {}
    for consumer,provider,channel in dependencies:
        if channel == 'name': reverse.setdefault(provider,[]).append(consumer)
    invalid = set()
    for provider,kind in mutations:
        if kind == 'style': invalid.add(provider); continue
        if kind not in ('text','remove'): continue
        pending = [provider]
        seen = set()
        while pending:
            node = pending.pop()
            if node in seen or node not in cache: continue
            seen.add(node)
            invalid.add(node)
            pending.extend(reverse.get(node,[]))
    return [{key:value for key,value in cache.items() if key not in invalid},[key for key in cache if key in invalid]]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('contract fixture 1', solve([{'a':'A','b':'B','c':str(N),'keep':'K'},[['b','a','name'],['c','b','name']],[['a','text']]],), [{'keep':'K'},['a','b','c']])
check('contract fixture 2', solve([{'c':'C'},[['c','missing','name']],[['missing','remove']]],), [{},['c']])
check('contract fixture 3', solve([{'a':'A','b':'B'},[['b','a','description']],[['a','text']]],), [{'b':'B'},['a']])
check('contract fixture 4', solve([{'a':'A','b':'B'},[['b','a','name']],[['a','style']]],), [{'b':'B'},['a']])
check('contract fixture 5', solve([{'a':'A','b':'B'},[['b','a','name'],['a','b','name']],[['a','unrelated']]],), [{'a':'A','b':'B'},[]])
check('contract fixture 6', solve([{'z':'Z','a':'A'},[['a','z','name'],['z','a','name']],[['z','text']]],), [{},['z','a']])
check('contract fixture 7', solve([{'a':'A','b':'B'},[],[['a','text'],['b','text']]],), [{},['a','b']])
check('contract fixture 8', solve([{'n'+str(i):'Name'+str(i) for i in range(N+2)},[['n'+str(i),'n'+str(i-1),'name'] for i in range(1,N+2)],[['n0','text']]],), [{},['n'+str(i) for i in range(N+2)]])
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	`[{'keep': 'K'}, ['a', 'b', 'c']]`	`[{'keep': 'K'}, ['a', 'b', 'c']]`	Passed
contract fixture 2	`[{'c': 'C'}, []]`	`[{}, ['c']]`	Failed
contract fixture 3	`[{'b': 'B'}, ['a']]`	`[{'b': 'B'}, ['a']]`	Passed
contract fixture 4	`[{'b': 'B'}, ['a']]`	`[{'b': 'B'}, ['a']]`	Passed
contract fixture 5	`[{'a': 'A', 'b': 'B'}, []]`	`[{'a': 'A', 'b': 'B'}, []]`	Passed
contract fixture 6	`[{}, ['z', 'a']]`	`[{}, ['z', 'a']]`	Passed
contract fixture 7	`[{}, ['a', 'b']]`	`[{}, ['a', 'b']]`	Passed
contract fixture 8	`[{}, ['n0', 'n1', 'n2']]`	`[{}, ['n0', 'n1', 'n2']]`	Passed

SHA-256 / 66f1a417973ca0b39e06bb501fdb0cc8ab41024d2149b14a29ceb6a676b6f295

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(data):
    cache,dependencies,mutations = data
    reverse = {}
    for consumer,provider,channel in dependencies:
        if channel == 'name': reverse.setdefault(provider,[]).append(consumer)
    invalid = set()
    for provider,kind in mutations:
        if kind == 'style': invalid.add(provider); continue
        if kind not in ('text','remove'): continue
        pending = [provider]
        seen = set()
        while pending:
            node = pending.pop()
            if node in seen or not cache.get(node): continue
            seen.add(node)
            invalid.add(node)
            pending.extend(reverse.get(node,[]))
    return [{key:value for key,value in cache.items() if key not in invalid},[key for key in cache if key in invalid]]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('contract fixture 1', solve([{'a':'A','b':'B','c':str(N),'keep':'K'},[['b','a','name'],['c','b','name']],[['a','text']]],), [{'keep':'K'},['a','b','c']])
check('contract fixture 2', solve([{'c':'C'},[['c','missing','name']],[['missing','remove']]],), [{},['c']])
check('contract fixture 3', solve([{'a':'A','b':'B'},[['b','a','description']],[['a','text']]],), [{'b':'B'},['a']])
check('contract fixture 4', solve([{'a':'A','b':'B'},[['b','a','name']],[['a','style']]],), [{'b':'B'},['a']])
check('contract fixture 5', solve([{'a':'A','b':'B'},[['b','a','name'],['a','b','name']],[['a','unrelated']]],), [{'a':'A','b':'B'},[]])
check('contract fixture 6', solve([{'z':'Z','a':'A'},[['a','z','name'],['z','a','name']],[['z','text']]],), [{},['z','a']])
check('contract fixture 7', solve([{'a':'A','b':'B'},[],[['a','text'],['b','text']]],), [{},['a','b']])
check('contract fixture 8', solve([{'n'+str(i):'Name'+str(i) for i in range(N+2)},[['n'+str(i),'n'+str(i-1),'name'] for i in range(1,N+2)],[['n0','text']]],), [{},['n'+str(i) for i in range(N+2)]])
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	`[{'keep': 'K'}, ['a', 'b', 'c']]`	`[{'keep': 'K'}, ['a', 'b', 'c']]`	Passed
contract fixture 2	`[{'c': 'C'}, []]`	`[{}, ['c']]`	Failed
contract fixture 3	`[{'b': 'B'}, ['a']]`	`[{'b': 'B'}, ['a']]`	Passed
contract fixture 4	`[{'b': 'B'}, ['a']]`	`[{'b': 'B'}, ['a']]`	Passed
contract fixture 5	`[{'a': 'A', 'b': 'B'}, []]`	`[{'a': 'A', 'b': 'B'}, []]`	Passed
contract fixture 6	`[{}, ['z', 'a']]`	`[{}, ['z', 'a']]`	Passed
contract fixture 7	`[{}, ['a', 'b']]`	`[{}, ['a', 'b']]`	Passed
contract fixture 8	`[{}, ['n0', 'n1', 'n2']]`	`[{}, ['n0', 'n1', 'n2']]`	Passed

SHA-256 / 1780ade5b33b7111a84d25a18a7153271212407c5389e01c54b478aa3bd82377

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 8 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.

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 2026-09-29T14:45:48.858649+00:00.

Case digest / 5e23a03cbd6c7a934a61b85c5b2193d1648b04a87f4edab079807f83b5c3ec9a