FAILURE MAP
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FA-37151 / Table interactions / Open access

Table cell draft lifecycle: draft cell owner · case 01

The table draft cell owner result violates the stipulated table cell draft lifecycle contract.

Verified by executionVariant 1 · 11 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The draft cell owner decision uses 'False' instead of "state.get('key')!=key".

THE FAILURE

The draft cell owner decision uses 'False' instead of "state.get('key')!=key".

Unsuccessful approach: The attempted repair "state.get('key',('',''))[0]!=key[0]" still loses a required part of the table contract.

Case contract

Cell drafts belong to a stable row-column pair and snapshot the original value and revision. Readonly cells cannot start/input/commit edits, cancellation discards the draft, commits validate required empty strings, reject stale revisions, and suppress unchanged writes.

Why this case matters

An offline table UI model isolates table cell draft lifecycle, including adversarial row/column relationships.

1 / The failure

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

N = 1
observations = []
def solve(row, column, draft, event, value, editable, validator, revision):
    key=(row['id'],column)
    state=dict(draft)
    if event=='begin' and editable: state={'key':key,'base':row[column],'value':row[column],'revision':revision,'error':None}
    if False: return {'draft':state,'write':None}
    if event=='input' and editable: state['value']=value
    if event=='cancel': return {'draft':{},'write':None}
    if event!='commit': return {'draft':state,'write':None}
    if not editable: return {'draft':state,'write':None}
    if state['revision']!=revision: state['error']='conflict'; return {'draft':state,'write':None}
    if validator=='required' and state['value']=='': state['error']='required'; return {'draft':state,'write':None}
    if state['value']==state['base']: return {'draft':{},'write':None}
    return {'draft':{},'write':{'row':row['id'],'column':column,'value':state['value'],'expected_revision':revision}}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('begin snapshot', solve({'id':'r','x':1}, 'x', {}, 'begin', 'placeholder', True, 'required', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 1, 'revision': 3, 'error': None}, 'write': None})
    check('cancel draft', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'cancel', None, True, '', 3), {'draft': {}, 'write': None})
    check('wrong column', solve({'id':'r','x':1}, 'x', {'key':('r','y'),'base':1,'value':2,'revision':3,'error':None}, 'commit', None, True, '', 3), {'draft': {'key': ('r', 'y'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('readonly input', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'input', 4, False, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('stale revision', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':2,'error':None}, 'commit', None, True, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 2, 'error': 'conflict'}, 'write': None})
    check('required empty', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':'','revision':3,'error':None}, 'commit', None, True, 'required', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': '', 'revision': 3, 'error': 'required'}, 'write': None})
    check('zero valid', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':0,'revision':3,'error':None}, 'commit', None, True, 'required', 3), {'draft': {}, 'write': {'row': 'r', 'column': 'x', 'value': 0, 'expected_revision': 3}})
    check('unchanged', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':1,'revision':3,'error':None}, 'commit', None, True, '', 3), {'draft': {}, 'write': None})
    check('readonly commit', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'commit', None, False, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('normal input', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'input', 5, True, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 5, 'revision': 3, 'error': None}, 'write': None})
    check('readonly begin', solve({'id':'r','x':1}, 'x', {}, 'begin', None, False, '', 3), {'draft': {}, 'write': None})

if N == 2:
    check('begin snapshot', solve({'id':'r','x':2}, 'x', {}, 'begin', 'placeholder', True, 'required', 3), {'draft': {'key': ('r', 'x'), 'base': 2, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('cancel draft', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'cancel', None, True, '', 3), {'draft': {}, 'write': None})
    check('wrong column', solve({'id':'r','x':1}, 'x', {'key':('r','y'),'base':1,'value':2,'revision':3,'error':None}, 'commit', None, True, '', 3), {'draft': {'key': ('r', 'y'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('readonly input', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'input', 4, False, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('stale revision', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':2,'error':None}, 'commit', None, True, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 2, 'error': 'conflict'}, 'write': None})
    check('required empty', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':'','revision':3,'error':None}, 'commit', None, True, 'required', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': '', 'revision': 3, 'error': 'required'}, 'write': None})
    check('zero valid', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':0,'revision':3,'error':None}, 'commit', None, True, 'required', 3), {'draft': {}, 'write': {'row': 'r', 'column': 'x', 'value': 0, 'expected_revision': 3}})
    check('unchanged', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':1,'revision':3,'error':None}, 'commit', None, True, '', 3), {'draft': {}, 'write': None})
    check('readonly commit', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'commit', None, False, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('normal input', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'input', 5, True, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 5, 'revision': 3, 'error': None}, 'write': None})
    check('readonly begin', solve({'id':'r','x':1}, 'x', {}, 'begin', None, False, '', 3), {'draft': {}, 'write': None})

if N == 3:
    check('begin snapshot', solve({'id':'r','x':3}, 'x', {}, 'begin', 'placeholder', True, 'required', 3), {'draft': {'key': ('r', 'x'), 'base': 3, 'value': 3, 'revision': 3, 'error': None}, 'write': None})
    check('cancel draft', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'cancel', None, True, '', 3), {'draft': {}, 'write': None})
    check('wrong column', solve({'id':'r','x':1}, 'x', {'key':('r','y'),'base':1,'value':2,'revision':3,'error':None}, 'commit', None, True, '', 3), {'draft': {'key': ('r', 'y'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('readonly input', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'input', 4, False, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('stale revision', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':2,'error':None}, 'commit', None, True, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 2, 'error': 'conflict'}, 'write': None})
    check('required empty', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':'','revision':3,'error':None}, 'commit', None, True, 'required', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': '', 'revision': 3, 'error': 'required'}, 'write': None})
    check('zero valid', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':0,'revision':3,'error':None}, 'commit', None, True, 'required', 3), {'draft': {}, 'write': {'row': 'r', 'column': 'x', 'value': 0, 'expected_revision': 3}})
    check('unchanged', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':1,'revision':3,'error':None}, 'commit', None, True, '', 3), {'draft': {}, 'write': None})
    check('readonly commit', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'commit', None, False, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('normal input', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'input', 5, True, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 5, 'revision': 3, 'error': None}, 'write': None})
    check('readonly begin', solve({'id':'r','x':1}, 'x', {}, 'begin', None, False, '', 3), {'draft': {}, 'write': None})

if N == 4:
    check('begin snapshot', solve({'id':'r','x':4}, 'x', {}, 'begin', 'placeholder', True, 'required', 3), {'draft': {'key': ('r', 'x'), 'base': 4, 'value': 4, 'revision': 3, 'error': None}, 'write': None})
    check('cancel draft', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'cancel', None, True, '', 3), {'draft': {}, 'write': None})
    check('wrong column', solve({'id':'r','x':1}, 'x', {'key':('r','y'),'base':1,'value':2,'revision':3,'error':None}, 'commit', None, True, '', 3), {'draft': {'key': ('r', 'y'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('readonly input', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'input', 4, False, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('stale revision', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':2,'error':None}, 'commit', None, True, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 2, 'error': 'conflict'}, 'write': None})
    check('required empty', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':'','revision':3,'error':None}, 'commit', None, True, 'required', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': '', 'revision': 3, 'error': 'required'}, 'write': None})
    check('zero valid', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':0,'revision':3,'error':None}, 'commit', None, True, 'required', 3), {'draft': {}, 'write': {'row': 'r', 'column': 'x', 'value': 0, 'expected_revision': 3}})
    check('unchanged', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':1,'revision':3,'error':None}, 'commit', None, True, '', 3), {'draft': {}, 'write': None})
    check('readonly commit', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'commit', None, False, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('normal input', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'input', 5, True, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 5, 'revision': 3, 'error': None}, 'write': None})
    check('readonly begin', solve({'id':'r','x':1}, 'x', {}, 'begin', None, False, '', 3), {'draft': {}, 'write': None})

if N == 5:
    check('begin snapshot', solve({'id':'r','x':5}, 'x', {}, 'begin', 'placeholder', True, 'required', 3), {'draft': {'key': ('r', 'x'), 'base': 5, 'value': 5, 'revision': 3, 'error': None}, 'write': None})
    check('cancel draft', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'cancel', None, True, '', 3), {'draft': {}, 'write': None})
    check('wrong column', solve({'id':'r','x':1}, 'x', {'key':('r','y'),'base':1,'value':2,'revision':3,'error':None}, 'commit', None, True, '', 3), {'draft': {'key': ('r', 'y'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('readonly input', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'input', 4, False, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('stale revision', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':2,'error':None}, 'commit', None, True, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 2, 'error': 'conflict'}, 'write': None})
    check('required empty', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':'','revision':3,'error':None}, 'commit', None, True, 'required', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': '', 'revision': 3, 'error': 'required'}, 'write': None})
    check('zero valid', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':0,'revision':3,'error':None}, 'commit', None, True, 'required', 3), {'draft': {}, 'write': {'row': 'r', 'column': 'x', 'value': 0, 'expected_revision': 3}})
    check('unchanged', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':1,'revision':3,'error':None}, 'commit', None, True, '', 3), {'draft': {}, 'write': None})
    check('readonly commit', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'commit', None, False, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('normal input', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'input', 5, True, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 5, 'revision': 3, 'error': None}, 'write': None})
    check('readonly begin', solve({'id':'r','x':1}, 'x', {}, 'begin', None, False, '', 3), {'draft': {}, 'write': None})

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
begin snapshot{'draft': {'base': 1, 'error': None, 'key': ['r', 'x'], 'revision': 3, 'value': 1}, 'write': None}{'draft': {'base': 1, 'error': None, 'key': ['r', 'x'], 'revision': 3, 'value': 1}, 'write': None}Passed
cancel draft{'draft': {}, 'write': None}{'draft': {}, 'write': None}Passed
wrong column{'draft': {}, 'write': {'column': 'x', 'expected_revision': 3, 'row': 'r', 'value': 2}}{'draft': {'base': 1, 'error': None, 'key': ['r', 'y'], 'revision': 3, 'value': 2}, 'write': None}Failed
readonly input{'draft': {'base': 1, 'error': None, 'key': ['r', 'x'], 'revision': 3, 'value': 2}, 'write': None}{'draft': {'base': 1, 'error': None, 'key': ['r', 'x'], 'revision': 3, 'value': 2}, 'write': None}Passed
stale revision{'draft': {'base': 1, 'error': 'conflict', 'key': ['r', 'x'], 'revision': 2, 'value': 2}, 'write': None}{'draft': {'base': 1, 'error': 'conflict', 'key': ['r', 'x'], 'revision': 2, 'value': 2}, 'write': None}Passed
required empty{'draft': {'base': 1, 'error': 'required', 'key': ['r', 'x'], 'revision': 3, 'value': ''}, 'write': None}{'draft': {'base': 1, 'error': 'required', 'key': ['r', 'x'], 'revision': 3, 'value': ''}, 'write': None}Passed
zero valid{'draft': {}, 'write': {'column': 'x', 'expected_revision': 3, 'row': 'r', 'value': 0}}{'draft': {}, 'write': {'column': 'x', 'expected_revision': 3, 'row': 'r', 'value': 0}}Passed
unchanged{'draft': {}, 'write': None}{'draft': {}, 'write': None}Passed
readonly commit{'draft': {'base': 1, 'error': None, 'key': ['r', 'x'], 'revision': 3, 'value': 2}, 'write': None}{'draft': {'base': 1, 'error': None, 'key': ['r', 'x'], 'revision': 3, 'value': 2}, 'write': None}Passed
normal input{'draft': {'base': 1, 'error': None, 'key': ['r', 'x'], 'revision': 3, 'value': 5}, 'write': None}{'draft': {'base': 1, 'error': None, 'key': ['r', 'x'], 'revision': 3, 'value': 5}, 'write': None}Passed
readonly begin{'draft': {}, 'write': None}{'draft': {}, 'write': None}Passed

SHA-256 / cb295e348beb1bcfe8d76d7df95e8202e45995e26cfa94e1f7d88c901e95b7f1

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(row, column, draft, event, value, editable, validator, revision):
    key=(row['id'],column)
    state=dict(draft)
    if event=='begin' and editable: state={'key':key,'base':row[column],'value':row[column],'revision':revision,'error':None}
    if state.get('key',('',''))[0]!=key[0]: return {'draft':state,'write':None}
    if event=='input' and editable: state['value']=value
    if event=='cancel': return {'draft':{},'write':None}
    if event!='commit': return {'draft':state,'write':None}
    if not editable: return {'draft':state,'write':None}
    if state['revision']!=revision: state['error']='conflict'; return {'draft':state,'write':None}
    if validator=='required' and state['value']=='': state['error']='required'; return {'draft':state,'write':None}
    if state['value']==state['base']: return {'draft':{},'write':None}
    return {'draft':{},'write':{'row':row['id'],'column':column,'value':state['value'],'expected_revision':revision}}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('begin snapshot', solve({'id':'r','x':1}, 'x', {}, 'begin', 'placeholder', True, 'required', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 1, 'revision': 3, 'error': None}, 'write': None})
    check('cancel draft', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'cancel', None, True, '', 3), {'draft': {}, 'write': None})
    check('wrong column', solve({'id':'r','x':1}, 'x', {'key':('r','y'),'base':1,'value':2,'revision':3,'error':None}, 'commit', None, True, '', 3), {'draft': {'key': ('r', 'y'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('readonly input', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'input', 4, False, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('stale revision', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':2,'error':None}, 'commit', None, True, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 2, 'error': 'conflict'}, 'write': None})
    check('required empty', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':'','revision':3,'error':None}, 'commit', None, True, 'required', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': '', 'revision': 3, 'error': 'required'}, 'write': None})
    check('zero valid', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':0,'revision':3,'error':None}, 'commit', None, True, 'required', 3), {'draft': {}, 'write': {'row': 'r', 'column': 'x', 'value': 0, 'expected_revision': 3}})
    check('unchanged', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':1,'revision':3,'error':None}, 'commit', None, True, '', 3), {'draft': {}, 'write': None})
    check('readonly commit', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'commit', None, False, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('normal input', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'input', 5, True, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 5, 'revision': 3, 'error': None}, 'write': None})
    check('readonly begin', solve({'id':'r','x':1}, 'x', {}, 'begin', None, False, '', 3), {'draft': {}, 'write': None})

if N == 2:
    check('begin snapshot', solve({'id':'r','x':2}, 'x', {}, 'begin', 'placeholder', True, 'required', 3), {'draft': {'key': ('r', 'x'), 'base': 2, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('cancel draft', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'cancel', None, True, '', 3), {'draft': {}, 'write': None})
    check('wrong column', solve({'id':'r','x':1}, 'x', {'key':('r','y'),'base':1,'value':2,'revision':3,'error':None}, 'commit', None, True, '', 3), {'draft': {'key': ('r', 'y'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('readonly input', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'input', 4, False, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('stale revision', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':2,'error':None}, 'commit', None, True, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 2, 'error': 'conflict'}, 'write': None})
    check('required empty', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':'','revision':3,'error':None}, 'commit', None, True, 'required', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': '', 'revision': 3, 'error': 'required'}, 'write': None})
    check('zero valid', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':0,'revision':3,'error':None}, 'commit', None, True, 'required', 3), {'draft': {}, 'write': {'row': 'r', 'column': 'x', 'value': 0, 'expected_revision': 3}})
    check('unchanged', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':1,'revision':3,'error':None}, 'commit', None, True, '', 3), {'draft': {}, 'write': None})
    check('readonly commit', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'commit', None, False, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('normal input', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'input', 5, True, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 5, 'revision': 3, 'error': None}, 'write': None})
    check('readonly begin', solve({'id':'r','x':1}, 'x', {}, 'begin', None, False, '', 3), {'draft': {}, 'write': None})

if N == 3:
    check('begin snapshot', solve({'id':'r','x':3}, 'x', {}, 'begin', 'placeholder', True, 'required', 3), {'draft': {'key': ('r', 'x'), 'base': 3, 'value': 3, 'revision': 3, 'error': None}, 'write': None})
    check('cancel draft', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'cancel', None, True, '', 3), {'draft': {}, 'write': None})
    check('wrong column', solve({'id':'r','x':1}, 'x', {'key':('r','y'),'base':1,'value':2,'revision':3,'error':None}, 'commit', None, True, '', 3), {'draft': {'key': ('r', 'y'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('readonly input', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'input', 4, False, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('stale revision', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':2,'error':None}, 'commit', None, True, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 2, 'error': 'conflict'}, 'write': None})
    check('required empty', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':'','revision':3,'error':None}, 'commit', None, True, 'required', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': '', 'revision': 3, 'error': 'required'}, 'write': None})
    check('zero valid', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':0,'revision':3,'error':None}, 'commit', None, True, 'required', 3), {'draft': {}, 'write': {'row': 'r', 'column': 'x', 'value': 0, 'expected_revision': 3}})
    check('unchanged', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':1,'revision':3,'error':None}, 'commit', None, True, '', 3), {'draft': {}, 'write': None})
    check('readonly commit', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'commit', None, False, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('normal input', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'input', 5, True, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 5, 'revision': 3, 'error': None}, 'write': None})
    check('readonly begin', solve({'id':'r','x':1}, 'x', {}, 'begin', None, False, '', 3), {'draft': {}, 'write': None})

if N == 4:
    check('begin snapshot', solve({'id':'r','x':4}, 'x', {}, 'begin', 'placeholder', True, 'required', 3), {'draft': {'key': ('r', 'x'), 'base': 4, 'value': 4, 'revision': 3, 'error': None}, 'write': None})
    check('cancel draft', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'cancel', None, True, '', 3), {'draft': {}, 'write': None})
    check('wrong column', solve({'id':'r','x':1}, 'x', {'key':('r','y'),'base':1,'value':2,'revision':3,'error':None}, 'commit', None, True, '', 3), {'draft': {'key': ('r', 'y'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('readonly input', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'input', 4, False, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('stale revision', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':2,'error':None}, 'commit', None, True, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 2, 'error': 'conflict'}, 'write': None})
    check('required empty', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':'','revision':3,'error':None}, 'commit', None, True, 'required', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': '', 'revision': 3, 'error': 'required'}, 'write': None})
    check('zero valid', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':0,'revision':3,'error':None}, 'commit', None, True, 'required', 3), {'draft': {}, 'write': {'row': 'r', 'column': 'x', 'value': 0, 'expected_revision': 3}})
    check('unchanged', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':1,'revision':3,'error':None}, 'commit', None, True, '', 3), {'draft': {}, 'write': None})
    check('readonly commit', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'commit', None, False, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('normal input', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'input', 5, True, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 5, 'revision': 3, 'error': None}, 'write': None})
    check('readonly begin', solve({'id':'r','x':1}, 'x', {}, 'begin', None, False, '', 3), {'draft': {}, 'write': None})

if N == 5:
    check('begin snapshot', solve({'id':'r','x':5}, 'x', {}, 'begin', 'placeholder', True, 'required', 3), {'draft': {'key': ('r', 'x'), 'base': 5, 'value': 5, 'revision': 3, 'error': None}, 'write': None})
    check('cancel draft', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'cancel', None, True, '', 3), {'draft': {}, 'write': None})
    check('wrong column', solve({'id':'r','x':1}, 'x', {'key':('r','y'),'base':1,'value':2,'revision':3,'error':None}, 'commit', None, True, '', 3), {'draft': {'key': ('r', 'y'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('readonly input', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'input', 4, False, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('stale revision', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':2,'error':None}, 'commit', None, True, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 2, 'error': 'conflict'}, 'write': None})
    check('required empty', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':'','revision':3,'error':None}, 'commit', None, True, 'required', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': '', 'revision': 3, 'error': 'required'}, 'write': None})
    check('zero valid', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':0,'revision':3,'error':None}, 'commit', None, True, 'required', 3), {'draft': {}, 'write': {'row': 'r', 'column': 'x', 'value': 0, 'expected_revision': 3}})
    check('unchanged', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':1,'revision':3,'error':None}, 'commit', None, True, '', 3), {'draft': {}, 'write': None})
    check('readonly commit', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'commit', None, False, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 2, 'revision': 3, 'error': None}, 'write': None})
    check('normal input', solve({'id':'r','x':1}, 'x', {'key':('r','x'),'base':1,'value':2,'revision':3,'error':None}, 'input', 5, True, '', 3), {'draft': {'key': ('r', 'x'), 'base': 1, 'value': 5, 'revision': 3, 'error': None}, 'write': None})
    check('readonly begin', solve({'id':'r','x':1}, 'x', {}, 'begin', None, False, '', 3), {'draft': {}, 'write': None})

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
begin snapshot{'draft': {'base': 1, 'error': None, 'key': ['r', 'x'], 'revision': 3, 'value': 1}, 'write': None}{'draft': {'base': 1, 'error': None, 'key': ['r', 'x'], 'revision': 3, 'value': 1}, 'write': None}Passed
cancel draft{'draft': {}, 'write': None}{'draft': {}, 'write': None}Passed
wrong column{'draft': {}, 'write': {'column': 'x', 'expected_revision': 3, 'row': 'r', 'value': 2}}{'draft': {'base': 1, 'error': None, 'key': ['r', 'y'], 'revision': 3, 'value': 2}, 'write': None}Failed
readonly input{'draft': {'base': 1, 'error': None, 'key': ['r', 'x'], 'revision': 3, 'value': 2}, 'write': None}{'draft': {'base': 1, 'error': None, 'key': ['r', 'x'], 'revision': 3, 'value': 2}, 'write': None}Passed
stale revision{'draft': {'base': 1, 'error': 'conflict', 'key': ['r', 'x'], 'revision': 2, 'value': 2}, 'write': None}{'draft': {'base': 1, 'error': 'conflict', 'key': ['r', 'x'], 'revision': 2, 'value': 2}, 'write': None}Passed
required empty{'draft': {'base': 1, 'error': 'required', 'key': ['r', 'x'], 'revision': 3, 'value': ''}, 'write': None}{'draft': {'base': 1, 'error': 'required', 'key': ['r', 'x'], 'revision': 3, 'value': ''}, 'write': None}Passed
zero valid{'draft': {}, 'write': {'column': 'x', 'expected_revision': 3, 'row': 'r', 'value': 0}}{'draft': {}, 'write': {'column': 'x', 'expected_revision': 3, 'row': 'r', 'value': 0}}Passed
unchanged{'draft': {}, 'write': None}{'draft': {}, 'write': None}Passed
readonly commit{'draft': {'base': 1, 'error': None, 'key': ['r', 'x'], 'revision': 3, 'value': 2}, 'write': None}{'draft': {'base': 1, 'error': None, 'key': ['r', 'x'], 'revision': 3, 'value': 2}, 'write': None}Passed
normal input{'draft': {'base': 1, 'error': None, 'key': ['r', 'x'], 'revision': 3, 'value': 5}, 'write': None}{'draft': {'base': 1, 'error': None, 'key': ['r', 'x'], 'revision': 3, 'value': 5}, 'write': None}Passed
readonly begin{'draft': {}, 'write': None}{'draft': {}, 'write': None}Passed

SHA-256 / 211cfebb6d53f85bc910fe59651464176ef55cc7425562b18cc302da5c95418f

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 11 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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Verification & scope

Existing owned drafts contain base, value, revision, and error fields; the column exists in the row. Deterministic offline table UI model; no browser, DOM, framework, or standards 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 2026-09-29T14:42:58.800999+00:00.

Case digest / 2446b05c358ecc38aac7f3b7db6d365c4f4920699ae6b1d14ffa3caf0fa1dbf9