FA-73951 / Feature flag rollout bucketing / Open access
Segment membership precedence: Absent attributes match null clause values · case 01
Users without a tier attribute join a segment whose clause lists null among its values.
ROOT CAUSE
The attribute is read with user.get, so absence becomes None and matches a None clause value.
VERIFIED REPAIR
Return no match when the attribute is absent before comparing values.
Unsuccessful approach: Defaulting absent attributes to the empty string trades the null collision for an empty-string one.
Case contract
A user is in the segment if its key is in included (reason included, which beats excluded); else not if its key is in excluded; else if some rule with a non-empty clause list has every clause matching (reason rule:i). A clause [attr, values] matches only when the attribute is present and its value (or any element of a list value) is in values. Otherwise [False, none].
Why this case matters
Segments are reused across many flags, so a precedence slip changes exposure everywhere at once.
1 / The failure
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(segment, user):
key = user.get('key')
def hit(clause):
attr, values = clause
value = user.get(attr)
items = value if isinstance(value, list) else [value]
return any(item in values for item in items)
if key in segment.get('included', []):
return [True, 'included']
if key in segment.get('excluded', []):
return [False, 'excluded']
for i, rule in enumerate(segment.get('rules', [])):
clauses = rule.get('clauses', [])
if clauses and all(hit(c) for c in clauses):
return [True, 'rule:%d' % i]
return [False, 'none']
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('explicit inclusion beats exclusion',
[{'included': ['k1'], 'excluded': ['k1'], 'rules': []}, {'key': 'k1'}],
[True, 'included']),
('exclusion blocks a matching rule',
[{'included': ['k2'], 'excluded': ['k1'], 'rules': [{'clauses': [['region', ['eu']]]}]},
{'key': 'k1', 'region': 'eu'}],
[False, 'excluded']),
('empty clause list never matches',
[{'included': [], 'excluded': [], 'rules': [{'clauses': []}]}, {'key': 'k3'}],
[False, 'none']),
('absent attribute does not match a null value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['tier', [None, 'gold']]]}]}, {'key': 'k3'}],
[False, 'none']),
('absent attribute does not match an empty string value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['region', ['']]]}]}, {'key': 'k4'}],
[False, 'none']),
('segment sample 1',
[{'included': ['k3'], 'excluded': ['k2', 'k1'], 'rules': [{'clauses': []}, {'clauses': []}]},
{'key': 'k2', 'groups': ['beta'], 'tier': 'gold'}],
[False, 'excluded']),
('segment sample 2',
[{'included': [], 'excluded': ['k4', 'k1'], 'rules': [{'clauses': [['groups', ['staff', 'gold']]]}]},
{'key': 'k4', 'region': 'eu'}],
[False, 'excluded']),
('segment sample 3',
[{'included': ['k4', 'k3'], 'excluded': ['k4'], 'rules': []}, {'key': 'k3'}],
[True, 'included'])],
[('exclusion blocks a matching rule',
[{'included': ['k2'], 'excluded': ['k1'], 'rules': [{'clauses': [['region', ['eu']]]}]},
{'key': 'k1', 'region': 'eu'}],
[False, 'excluded']),
('empty clause list never matches',
[{'included': [], 'excluded': [], 'rules': [{'clauses': []}]}, {'key': 'k3'}],
[False, 'none']),
('absent attribute does not match a null value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['tier', [None, 'gold']]]}]}, {'key': 'k3'}],
[False, 'none']),
('absent attribute does not match an empty string value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['region', ['']]]}]}, {'key': 'k4'}],
[False, 'none']),
('list attribute matches through any element',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['groups', ['beta']]]}]},
{'key': 'k2', 'groups': ['staff', 'beta']}],
[True, 'rule:0']),
('segment sample 6',
[{'included': ['k4'], 'excluded': [], 'rules': []}, {'key': 'k2', 'region': 'us'}],
[False, 'none']),
('segment sample 20',
[{'included': ['k3', 'k2'],
'excluded': [],
'rules': [{'clauses': [['tier', ['eu', 'gold']], ['tier', [None, 'gold']]]},
{'clauses': [['tier', [None, '']]]}]},
{'key': 'k4', 'region': ''}],
[False, 'none']),
('segment sample 53',
[{'included': ['k4', 'k3'],
'excluded': ['k4'],
'rules': [{'clauses': [['groups', ['', 'gold']], ['groups', ['', 'gold']]]}]},
{'key': 'k9', 'region': 'eu', 'tier': 'gold'}],
[False, 'none'])],
[('empty clause list never matches',
[{'included': [], 'excluded': [], 'rules': [{'clauses': []}]}, {'key': 'k3'}],
[False, 'none']),
('absent attribute does not match a null value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['tier', [None, 'gold']]]}]}, {'key': 'k3'}],
[False, 'none']),
('absent attribute does not match an empty string value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['region', ['']]]}]}, {'key': 'k4'}],
[False, 'none']),
('list attribute matches through any element',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['groups', ['beta']]]}]},
{'key': 'k2', 'groups': ['staff', 'beta']}],
[True, 'rule:0']),
('empty list attribute is not a member',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['groups', ['beta']]]}]},
{'key': 'k2', 'groups': []}],
[False, 'none']),
('segment sample 11',
[{'included': ['k1'], 'excluded': ['k3'], 'rules': [{'clauses': []}]},
{'key': 'k2', 'groups': ['staff', 'eu'], 'tier': 'gold'}],
[False, 'none']),
('segment sample 37',
[{'included': ['k4', 'k3'],
'excluded': [],
'rules': [{'clauses': [['groups', [None, 'staff']]]}, {'clauses': [['region', ['staff', '']]]}]},
{'key': 'k1', 'groups': 'beta'}],
[False, 'none']),
('segment sample 42',
[{'included': [],
'excluded': ['k4'],
'rules': [{'clauses': [['region', ['gold', 'eu']], ['region', ['staff', '']]]},
{'clauses': [['tier', [None, 'eu']]]}]},
{'key': 'k3', 'groups': ['x'], 'region': ''}],
[False, 'none'])],
[('absent attribute does not match a null value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['tier', [None, 'gold']]]}]}, {'key': 'k3'}],
[False, 'none']),
('absent attribute does not match an empty string value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['region', ['']]]}]}, {'key': 'k4'}],
[False, 'none']),
('list attribute matches through any element',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['groups', ['beta']]]}]},
{'key': 'k2', 'groups': ['staff', 'beta']}],
[True, 'rule:0']),
('empty list attribute is not a member',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['groups', ['beta']]]}]},
{'key': 'k2', 'groups': []}],
[False, 'none']),
('all clauses must match',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['region', ['eu']], ['groups', ['beta']]]}]},
{'key': 'k1', 'region': 'eu', 'groups': ['x']}],
[False, 'none']),
('segment sample 9',
[{'included': ['k3', 'k1'], 'excluded': [], 'rules': [{'clauses': [['tier', ['eu', None]]]}]},
{'key': 'k2', 'groups': ['beta']}],
[False, 'none']),
('segment sample 13',
[{'included': ['k1', 'k4'],
'excluded': [],
'rules': [{'clauses': []}, {'clauses': [['region', ['', 'eu']]]}]},
{'key': 'k3', 'groups': 'beta', 'tier': None}],
[False, 'none']),
('segment sample 16',
[{'included': ['k3', 'k1'], 'excluded': [], 'rules': [{'clauses': [['groups', ['gold', 'staff']]]}]},
{'key': 'k2', 'groups': ['beta', 'staff'], 'region': 'eu'}],
[True, 'rule:0'])],
[('absent attribute does not match an empty string value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['region', ['']]]}]}, {'key': 'k4'}],
[False, 'none']),
('list attribute matches through any element',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['groups', ['beta']]]}]},
{'key': 'k2', 'groups': ['staff', 'beta']}],
[True, 'rule:0']),
('empty list attribute is not a member',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['groups', ['beta']]]}]},
{'key': 'k2', 'groups': []}],
[False, 'none']),
('all clauses must match',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['region', ['eu']], ['groups', ['beta']]]}]},
{'key': 'k1', 'region': 'eu', 'groups': ['x']}],
[False, 'none']),
('second rule index',
[{'included': [],
'excluded': [],
'rules': [{'clauses': [['region', ['us']]]}, {'clauses': [['region', ['eu']]]}]},
{'key': 'k1', 'region': 'eu'}],
[True, 'rule:1']),
('segment sample 4',
[{'included': ['k1', 'k2'], 'excluded': [], 'rules': [{'clauses': [['groups', ['', 'beta']]]}]},
{'key': 'k4', 'region': 'eu'}],
[False, 'none']),
('segment sample 21',
[{'included': ['k3'], 'excluded': [], 'rules': []}, {'key': 'k9', 'groups': 'beta'}],
[False, 'none']),
('segment sample 31',
[{'included': ['k2', 'k4'],
'excluded': ['k4'],
'rules': [{'clauses': [['groups', ['gold', None]]]}, {'clauses': [['groups', ['gold', 'beta']]]}]},
{'key': 'k1', 'region': 'us'}],
[False, 'none'])]]
for label, args, expected in fixtures[N - 1]:
check(label, solve(*args), 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 fixture | Actual | Expected | Outcome |
|---|---|---|---|
| explicit inclusion beats exclusion | [True, 'included'] | [True, 'included'] | Passed |
| exclusion blocks a matching rule | [False, 'excluded'] | [False, 'excluded'] | Passed |
| empty clause list never matches | [False, 'none'] | [False, 'none'] | Passed |
| absent attribute does not match a null value | [True, 'rule:0'] | [False, 'none'] | Failed |
| absent attribute does not match an empty string value | [False, 'none'] | [False, 'none'] | Passed |
| segment sample 1 | [False, 'excluded'] | [False, 'excluded'] | Passed |
| segment sample 2 | [False, 'excluded'] | [False, 'excluded'] | Passed |
| segment sample 3 | [True, 'included'] | [True, 'included'] | Passed |
SHA-256 / 711f440dea385ff378498669f2ae9f82d11b228168a830e0f83e909548b7257a
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(segment, user):
key = user.get('key')
def hit(clause):
attr, values = clause
value = user.get(attr, '')
items = value if isinstance(value, list) else [value]
return any(item in values for item in items)
if key in segment.get('included', []):
return [True, 'included']
if key in segment.get('excluded', []):
return [False, 'excluded']
for i, rule in enumerate(segment.get('rules', [])):
clauses = rule.get('clauses', [])
if clauses and all(hit(c) for c in clauses):
return [True, 'rule:%d' % i]
return [False, 'none']
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('explicit inclusion beats exclusion',
[{'included': ['k1'], 'excluded': ['k1'], 'rules': []}, {'key': 'k1'}],
[True, 'included']),
('exclusion blocks a matching rule',
[{'included': ['k2'], 'excluded': ['k1'], 'rules': [{'clauses': [['region', ['eu']]]}]},
{'key': 'k1', 'region': 'eu'}],
[False, 'excluded']),
('empty clause list never matches',
[{'included': [], 'excluded': [], 'rules': [{'clauses': []}]}, {'key': 'k3'}],
[False, 'none']),
('absent attribute does not match a null value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['tier', [None, 'gold']]]}]}, {'key': 'k3'}],
[False, 'none']),
('absent attribute does not match an empty string value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['region', ['']]]}]}, {'key': 'k4'}],
[False, 'none']),
('segment sample 1',
[{'included': ['k3'], 'excluded': ['k2', 'k1'], 'rules': [{'clauses': []}, {'clauses': []}]},
{'key': 'k2', 'groups': ['beta'], 'tier': 'gold'}],
[False, 'excluded']),
('segment sample 2',
[{'included': [], 'excluded': ['k4', 'k1'], 'rules': [{'clauses': [['groups', ['staff', 'gold']]]}]},
{'key': 'k4', 'region': 'eu'}],
[False, 'excluded']),
('segment sample 3',
[{'included': ['k4', 'k3'], 'excluded': ['k4'], 'rules': []}, {'key': 'k3'}],
[True, 'included'])],
[('exclusion blocks a matching rule',
[{'included': ['k2'], 'excluded': ['k1'], 'rules': [{'clauses': [['region', ['eu']]]}]},
{'key': 'k1', 'region': 'eu'}],
[False, 'excluded']),
('empty clause list never matches',
[{'included': [], 'excluded': [], 'rules': [{'clauses': []}]}, {'key': 'k3'}],
[False, 'none']),
('absent attribute does not match a null value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['tier', [None, 'gold']]]}]}, {'key': 'k3'}],
[False, 'none']),
('absent attribute does not match an empty string value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['region', ['']]]}]}, {'key': 'k4'}],
[False, 'none']),
('list attribute matches through any element',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['groups', ['beta']]]}]},
{'key': 'k2', 'groups': ['staff', 'beta']}],
[True, 'rule:0']),
('segment sample 6',
[{'included': ['k4'], 'excluded': [], 'rules': []}, {'key': 'k2', 'region': 'us'}],
[False, 'none']),
('segment sample 20',
[{'included': ['k3', 'k2'],
'excluded': [],
'rules': [{'clauses': [['tier', ['eu', 'gold']], ['tier', [None, 'gold']]]},
{'clauses': [['tier', [None, '']]]}]},
{'key': 'k4', 'region': ''}],
[False, 'none']),
('segment sample 53',
[{'included': ['k4', 'k3'],
'excluded': ['k4'],
'rules': [{'clauses': [['groups', ['', 'gold']], ['groups', ['', 'gold']]]}]},
{'key': 'k9', 'region': 'eu', 'tier': 'gold'}],
[False, 'none'])],
[('empty clause list never matches',
[{'included': [], 'excluded': [], 'rules': [{'clauses': []}]}, {'key': 'k3'}],
[False, 'none']),
('absent attribute does not match a null value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['tier', [None, 'gold']]]}]}, {'key': 'k3'}],
[False, 'none']),
('absent attribute does not match an empty string value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['region', ['']]]}]}, {'key': 'k4'}],
[False, 'none']),
('list attribute matches through any element',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['groups', ['beta']]]}]},
{'key': 'k2', 'groups': ['staff', 'beta']}],
[True, 'rule:0']),
('empty list attribute is not a member',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['groups', ['beta']]]}]},
{'key': 'k2', 'groups': []}],
[False, 'none']),
('segment sample 11',
[{'included': ['k1'], 'excluded': ['k3'], 'rules': [{'clauses': []}]},
{'key': 'k2', 'groups': ['staff', 'eu'], 'tier': 'gold'}],
[False, 'none']),
('segment sample 37',
[{'included': ['k4', 'k3'],
'excluded': [],
'rules': [{'clauses': [['groups', [None, 'staff']]]}, {'clauses': [['region', ['staff', '']]]}]},
{'key': 'k1', 'groups': 'beta'}],
[False, 'none']),
('segment sample 42',
[{'included': [],
'excluded': ['k4'],
'rules': [{'clauses': [['region', ['gold', 'eu']], ['region', ['staff', '']]]},
{'clauses': [['tier', [None, 'eu']]]}]},
{'key': 'k3', 'groups': ['x'], 'region': ''}],
[False, 'none'])],
[('absent attribute does not match a null value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['tier', [None, 'gold']]]}]}, {'key': 'k3'}],
[False, 'none']),
('absent attribute does not match an empty string value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['region', ['']]]}]}, {'key': 'k4'}],
[False, 'none']),
('list attribute matches through any element',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['groups', ['beta']]]}]},
{'key': 'k2', 'groups': ['staff', 'beta']}],
[True, 'rule:0']),
('empty list attribute is not a member',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['groups', ['beta']]]}]},
{'key': 'k2', 'groups': []}],
[False, 'none']),
('all clauses must match',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['region', ['eu']], ['groups', ['beta']]]}]},
{'key': 'k1', 'region': 'eu', 'groups': ['x']}],
[False, 'none']),
('segment sample 9',
[{'included': ['k3', 'k1'], 'excluded': [], 'rules': [{'clauses': [['tier', ['eu', None]]]}]},
{'key': 'k2', 'groups': ['beta']}],
[False, 'none']),
('segment sample 13',
[{'included': ['k1', 'k4'],
'excluded': [],
'rules': [{'clauses': []}, {'clauses': [['region', ['', 'eu']]]}]},
{'key': 'k3', 'groups': 'beta', 'tier': None}],
[False, 'none']),
('segment sample 16',
[{'included': ['k3', 'k1'], 'excluded': [], 'rules': [{'clauses': [['groups', ['gold', 'staff']]]}]},
{'key': 'k2', 'groups': ['beta', 'staff'], 'region': 'eu'}],
[True, 'rule:0'])],
[('absent attribute does not match an empty string value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['region', ['']]]}]}, {'key': 'k4'}],
[False, 'none']),
('list attribute matches through any element',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['groups', ['beta']]]}]},
{'key': 'k2', 'groups': ['staff', 'beta']}],
[True, 'rule:0']),
('empty list attribute is not a member',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['groups', ['beta']]]}]},
{'key': 'k2', 'groups': []}],
[False, 'none']),
('all clauses must match',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['region', ['eu']], ['groups', ['beta']]]}]},
{'key': 'k1', 'region': 'eu', 'groups': ['x']}],
[False, 'none']),
('second rule index',
[{'included': [],
'excluded': [],
'rules': [{'clauses': [['region', ['us']]]}, {'clauses': [['region', ['eu']]]}]},
{'key': 'k1', 'region': 'eu'}],
[True, 'rule:1']),
('segment sample 4',
[{'included': ['k1', 'k2'], 'excluded': [], 'rules': [{'clauses': [['groups', ['', 'beta']]]}]},
{'key': 'k4', 'region': 'eu'}],
[False, 'none']),
('segment sample 21',
[{'included': ['k3'], 'excluded': [], 'rules': []}, {'key': 'k9', 'groups': 'beta'}],
[False, 'none']),
('segment sample 31',
[{'included': ['k2', 'k4'],
'excluded': ['k4'],
'rules': [{'clauses': [['groups', ['gold', None]]]}, {'clauses': [['groups', ['gold', 'beta']]]}]},
{'key': 'k1', 'region': 'us'}],
[False, 'none'])]]
for label, args, expected in fixtures[N - 1]:
check(label, solve(*args), 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 fixture | Actual | Expected | Outcome |
|---|---|---|---|
| explicit inclusion beats exclusion | [True, 'included'] | [True, 'included'] | Passed |
| exclusion blocks a matching rule | [False, 'excluded'] | [False, 'excluded'] | Passed |
| empty clause list never matches | [False, 'none'] | [False, 'none'] | Passed |
| absent attribute does not match a null value | [False, 'none'] | [False, 'none'] | Passed |
| absent attribute does not match an empty string value | [True, 'rule:0'] | [False, 'none'] | Failed |
| segment sample 1 | [False, 'excluded'] | [False, 'excluded'] | Passed |
| segment sample 2 | [False, 'excluded'] | [False, 'excluded'] | Passed |
| segment sample 3 | [True, 'included'] | [True, 'included'] | Passed |
SHA-256 / e1b2f9b2c8ef371185017c61fa95503057fafc0dadf59c6a5c68d87f8d009d67
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(segment, user):
key = user.get('key')
def hit(clause):
attr, values = clause
if attr not in user:
return False
value = user[attr]
items = value if isinstance(value, list) else [value]
return any(item in values for item in items)
if key in segment.get('included', []):
return [True, 'included']
if key in segment.get('excluded', []):
return [False, 'excluded']
for i, rule in enumerate(segment.get('rules', [])):
clauses = rule.get('clauses', [])
if clauses and all(hit(c) for c in clauses):
return [True, 'rule:%d' % i]
return [False, 'none']
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('explicit inclusion beats exclusion',
[{'included': ['k1'], 'excluded': ['k1'], 'rules': []}, {'key': 'k1'}],
[True, 'included']),
('exclusion blocks a matching rule',
[{'included': ['k2'], 'excluded': ['k1'], 'rules': [{'clauses': [['region', ['eu']]]}]},
{'key': 'k1', 'region': 'eu'}],
[False, 'excluded']),
('empty clause list never matches',
[{'included': [], 'excluded': [], 'rules': [{'clauses': []}]}, {'key': 'k3'}],
[False, 'none']),
('absent attribute does not match a null value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['tier', [None, 'gold']]]}]}, {'key': 'k3'}],
[False, 'none']),
('absent attribute does not match an empty string value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['region', ['']]]}]}, {'key': 'k4'}],
[False, 'none']),
('segment sample 1',
[{'included': ['k3'], 'excluded': ['k2', 'k1'], 'rules': [{'clauses': []}, {'clauses': []}]},
{'key': 'k2', 'groups': ['beta'], 'tier': 'gold'}],
[False, 'excluded']),
('segment sample 2',
[{'included': [], 'excluded': ['k4', 'k1'], 'rules': [{'clauses': [['groups', ['staff', 'gold']]]}]},
{'key': 'k4', 'region': 'eu'}],
[False, 'excluded']),
('segment sample 3',
[{'included': ['k4', 'k3'], 'excluded': ['k4'], 'rules': []}, {'key': 'k3'}],
[True, 'included'])],
[('exclusion blocks a matching rule',
[{'included': ['k2'], 'excluded': ['k1'], 'rules': [{'clauses': [['region', ['eu']]]}]},
{'key': 'k1', 'region': 'eu'}],
[False, 'excluded']),
('empty clause list never matches',
[{'included': [], 'excluded': [], 'rules': [{'clauses': []}]}, {'key': 'k3'}],
[False, 'none']),
('absent attribute does not match a null value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['tier', [None, 'gold']]]}]}, {'key': 'k3'}],
[False, 'none']),
('absent attribute does not match an empty string value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['region', ['']]]}]}, {'key': 'k4'}],
[False, 'none']),
('list attribute matches through any element',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['groups', ['beta']]]}]},
{'key': 'k2', 'groups': ['staff', 'beta']}],
[True, 'rule:0']),
('segment sample 6',
[{'included': ['k4'], 'excluded': [], 'rules': []}, {'key': 'k2', 'region': 'us'}],
[False, 'none']),
('segment sample 20',
[{'included': ['k3', 'k2'],
'excluded': [],
'rules': [{'clauses': [['tier', ['eu', 'gold']], ['tier', [None, 'gold']]]},
{'clauses': [['tier', [None, '']]]}]},
{'key': 'k4', 'region': ''}],
[False, 'none']),
('segment sample 53',
[{'included': ['k4', 'k3'],
'excluded': ['k4'],
'rules': [{'clauses': [['groups', ['', 'gold']], ['groups', ['', 'gold']]]}]},
{'key': 'k9', 'region': 'eu', 'tier': 'gold'}],
[False, 'none'])],
[('empty clause list never matches',
[{'included': [], 'excluded': [], 'rules': [{'clauses': []}]}, {'key': 'k3'}],
[False, 'none']),
('absent attribute does not match a null value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['tier', [None, 'gold']]]}]}, {'key': 'k3'}],
[False, 'none']),
('absent attribute does not match an empty string value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['region', ['']]]}]}, {'key': 'k4'}],
[False, 'none']),
('list attribute matches through any element',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['groups', ['beta']]]}]},
{'key': 'k2', 'groups': ['staff', 'beta']}],
[True, 'rule:0']),
('empty list attribute is not a member',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['groups', ['beta']]]}]},
{'key': 'k2', 'groups': []}],
[False, 'none']),
('segment sample 11',
[{'included': ['k1'], 'excluded': ['k3'], 'rules': [{'clauses': []}]},
{'key': 'k2', 'groups': ['staff', 'eu'], 'tier': 'gold'}],
[False, 'none']),
('segment sample 37',
[{'included': ['k4', 'k3'],
'excluded': [],
'rules': [{'clauses': [['groups', [None, 'staff']]]}, {'clauses': [['region', ['staff', '']]]}]},
{'key': 'k1', 'groups': 'beta'}],
[False, 'none']),
('segment sample 42',
[{'included': [],
'excluded': ['k4'],
'rules': [{'clauses': [['region', ['gold', 'eu']], ['region', ['staff', '']]]},
{'clauses': [['tier', [None, 'eu']]]}]},
{'key': 'k3', 'groups': ['x'], 'region': ''}],
[False, 'none'])],
[('absent attribute does not match a null value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['tier', [None, 'gold']]]}]}, {'key': 'k3'}],
[False, 'none']),
('absent attribute does not match an empty string value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['region', ['']]]}]}, {'key': 'k4'}],
[False, 'none']),
('list attribute matches through any element',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['groups', ['beta']]]}]},
{'key': 'k2', 'groups': ['staff', 'beta']}],
[True, 'rule:0']),
('empty list attribute is not a member',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['groups', ['beta']]]}]},
{'key': 'k2', 'groups': []}],
[False, 'none']),
('all clauses must match',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['region', ['eu']], ['groups', ['beta']]]}]},
{'key': 'k1', 'region': 'eu', 'groups': ['x']}],
[False, 'none']),
('segment sample 9',
[{'included': ['k3', 'k1'], 'excluded': [], 'rules': [{'clauses': [['tier', ['eu', None]]]}]},
{'key': 'k2', 'groups': ['beta']}],
[False, 'none']),
('segment sample 13',
[{'included': ['k1', 'k4'],
'excluded': [],
'rules': [{'clauses': []}, {'clauses': [['region', ['', 'eu']]]}]},
{'key': 'k3', 'groups': 'beta', 'tier': None}],
[False, 'none']),
('segment sample 16',
[{'included': ['k3', 'k1'], 'excluded': [], 'rules': [{'clauses': [['groups', ['gold', 'staff']]]}]},
{'key': 'k2', 'groups': ['beta', 'staff'], 'region': 'eu'}],
[True, 'rule:0'])],
[('absent attribute does not match an empty string value',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['region', ['']]]}]}, {'key': 'k4'}],
[False, 'none']),
('list attribute matches through any element',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['groups', ['beta']]]}]},
{'key': 'k2', 'groups': ['staff', 'beta']}],
[True, 'rule:0']),
('empty list attribute is not a member',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['groups', ['beta']]]}]},
{'key': 'k2', 'groups': []}],
[False, 'none']),
('all clauses must match',
[{'included': [], 'excluded': [], 'rules': [{'clauses': [['region', ['eu']], ['groups', ['beta']]]}]},
{'key': 'k1', 'region': 'eu', 'groups': ['x']}],
[False, 'none']),
('second rule index',
[{'included': [],
'excluded': [],
'rules': [{'clauses': [['region', ['us']]]}, {'clauses': [['region', ['eu']]]}]},
{'key': 'k1', 'region': 'eu'}],
[True, 'rule:1']),
('segment sample 4',
[{'included': ['k1', 'k2'], 'excluded': [], 'rules': [{'clauses': [['groups', ['', 'beta']]]}]},
{'key': 'k4', 'region': 'eu'}],
[False, 'none']),
('segment sample 21',
[{'included': ['k3'], 'excluded': [], 'rules': []}, {'key': 'k9', 'groups': 'beta'}],
[False, 'none']),
('segment sample 31',
[{'included': ['k2', 'k4'],
'excluded': ['k4'],
'rules': [{'clauses': [['groups', ['gold', None]]]}, {'clauses': [['groups', ['gold', 'beta']]]}]},
{'key': 'k1', 'region': 'us'}],
[False, 'none'])]]
for label, args, expected in fixtures[N - 1]:
check(label, solve(*args), 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 fixture | Actual | Expected | Outcome |
|---|---|---|---|
| explicit inclusion beats exclusion | [True, 'included'] | [True, 'included'] | Passed |
| exclusion blocks a matching rule | [False, 'excluded'] | [False, 'excluded'] | Passed |
| empty clause list never matches | [False, 'none'] | [False, 'none'] | Passed |
| absent attribute does not match a null value | [False, 'none'] | [False, 'none'] | Passed |
| absent attribute does not match an empty string value | [False, 'none'] | [False, 'none'] | Passed |
| segment sample 1 | [False, 'excluded'] | [False, 'excluded'] | Passed |
| segment sample 2 | [False, 'excluded'] | [False, 'excluded'] | Passed |
| segment sample 3 | [True, 'included'] | [True, 'included'] | Passed |
SHA-256 / 8de98ae7066ac71f343fb0347239cb0b1d2abbbc65ed742e9aef3cf47e76647e
Verification & scope
A deterministic toy flag-evaluation model with a stipulated contract; it does not reproduce any vendor SDK byte for byte. 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 2026-09-29T14:48:52.240398+00:00.
Case digest / 42c0cf0fe7647146ad8bc45bc9b9c9d1e521e6815e1cad6a1ac84f90c06abf99