FA-24741 / Client state / Open access

A child loader is started before its parent route data is available · case 01

A child loader is started before its parent route data is available.

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

ROOT CAUSE

The faulty implementation violates A route loader starts only after its immediate parent data is resolved; settled loaders do not restart, and siblings preserve declaration order.

VERIFIED REPAIR

A route loader starts only after its immediate parent data is resolved; settled loaders do not restart, and siblings preserve declaration order.

Unsuccessful approach: The partial repair still violates at least one explicit regression oracle.

Case contract

A route loader starts only after its immediate parent data is resolved; settled loaders do not restart, and siblings preserve declaration order.

Why this case matters

A bounded offline client-state transition with explicit lifecycle inputs.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(routes, resolved):
    return [key for key,parent in routes if key not in resolved]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('root ready only', solve([('root',None),('child','root')],[]), ['root'])
check('child after parent', solve([('root',None),('child','root')],['root']), ['child'])
check('siblings', solve([('a','root'),('b','root')],['root']), ['a','b'])
check('all settled', solve([('a',None)],['a']), [])
check('missing parent', solve([('a','missing')],[]), [])
check('parameterized chain', solve([(str(i),None if i==0 else str(i-1)) for i in range(N+2)],[str(i) for i in range(N)]), [str(N)])
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
root ready only	`['root', 'child']`	`['root']`	Failed
child after parent	`['child']`	`['child']`	Passed
siblings	`['a', 'b']`	`['a', 'b']`	Passed
all settled	`[]`	`[]`	Passed
missing parent	`['a']`	`[]`	Failed
parameterized chain	`['1', '2']`	`['1']`	Failed

SHA-256 / 06ac6554abd65e6e13d31884777802dd3b75e4c7b19a2b9e0942e261f3a303e0

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(routes, resolved):
    return [key for key,parent in routes if key not in resolved and parent is None]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('root ready only', solve([('root',None),('child','root')],[]), ['root'])
check('child after parent', solve([('root',None),('child','root')],['root']), ['child'])
check('siblings', solve([('a','root'),('b','root')],['root']), ['a','b'])
check('all settled', solve([('a',None)],['a']), [])
check('missing parent', solve([('a','missing')],[]), [])
check('parameterized chain', solve([(str(i),None if i==0 else str(i-1)) for i in range(N+2)],[str(i) for i in range(N)]), [str(N)])
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
root ready only	`['root']`	`['root']`	Passed
child after parent	`[]`	`['child']`	Failed
siblings	`[]`	`['a', 'b']`	Failed
all settled	`[]`	`[]`	Passed
missing parent	`[]`	`[]`	Passed
parameterized chain	`[]`	`['1']`	Failed

SHA-256 / c932356756ff99a8bc854bb95a515169223b8871c35ed2efee6207a6d0986d7f

3 / The verified repair

Exit 0

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

N = 1
observations = []
def solve(routes, resolved):
    return [key for key,parent in routes if key not in resolved and (parent is None or parent in resolved)]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('root ready only', solve([('root',None),('child','root')],[]), ['root'])
check('child after parent', solve([('root',None),('child','root')],['root']), ['child'])
check('siblings', solve([('a','root'),('b','root')],['root']), ['a','b'])
check('all settled', solve([('a',None)],['a']), [])
check('missing parent', solve([('a','missing')],[]), [])
check('parameterized chain', solve([(str(i),None if i==0 else str(i-1)) for i in range(N+2)],[str(i) for i in range(N)]), [str(N)])
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
root ready only	`['root']`	`['root']`	Passed
child after parent	`['child']`	`['child']`	Passed
siblings	`['a', 'b']`	`['a', 'b']`	Passed
all settled	`[]`	`[]`	Passed
missing parent	`[]`	`[]`	Passed
parameterized chain	`['1']`	`['1']`	Passed

SHA-256 / cd2bceebff51ef53a128fef9bc45af9eb58556121f53894221579b51b364b593

Verification & scope

This models the stated application policy only; no browser or framework conformance is claimed. 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 2026-09-29T14:41:00.332076+00:00.

Case digest / ed46b72f683d3eb7d4f876ec5b01f5dc33369a9c18e14df0c3f0752dec7abca6