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

N = 1
observations = []
def solve(d):
    return {'undo-snapshot':(d['history'][-1] if d['history'] else d['current']), 'undo-tail':(d['history'][:-1]), 'redo-snapshot':(d['future'][-1] if d['future'] else d['current']), 'branch-future':([] if d['new_edit'] else d['future']), 'noop-history':(d['history'] if set(d['next'])==set(d['current']) else d['history']+[d['current']]), 'undo-available':(bool(d['history']) and not d['applying'])}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = {1: [({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': False})], 2: [({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a'], ['b']], 'undo-available': True})], 3: [({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False})], 4: [({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': True}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False})], 5: [({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False})]}
for index, (data, expected) in enumerate(fixtures[N]):
    check("contract fixture " + str(index), solve(data), 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)

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

N = 1
observations = []
def solve(d):
    return {'undo-snapshot':(d['history'][-1] if d['history'] else d['current']), 'undo-tail':(d['history'][:-1]), 'redo-snapshot':([] if not d['future'] else d['future'][0]), 'branch-future':([] if d['new_edit'] else d['future']), 'noop-history':(d['history'] if set(d['next'])==set(d['current']) else d['history']+[d['current']]), 'undo-available':(bool(d['history']) and not d['applying'])}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = {1: [({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': False})], 2: [({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a'], ['b']], 'undo-available': True})], 3: [({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False})], 4: [({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': True}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False})], 5: [({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False})]}
for index, (data, expected) in enumerate(fixtures[N]):
    check("contract fixture " + str(index), solve(data), 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)

prompt:
Redo restores the first future filter snapshot is violated by the widget projection.

Each filter edit transaction records before and after snapshots. Undo/redo moves whole constraint snapshots and does not resurrect history after a new branch edit. This example checks: Redo restores the first future filter snapshot.

split: open-access


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

N = 1
observations = []
def solve(d):
    return {'undo-snapshot':(d['history'][-1] if d['history'] else d['current']), 'undo-tail':(d['history'][:-1]), 'redo-snapshot':(d['future'][0] if d['future'] else d['current']), 'branch-future':(d['future']), 'noop-history':(d['history'] if set(d['next'])==set(d['current']) else d['history']+[d['current']]), 'undo-available':(bool(d['history']) and not d['applying'])}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = {1: [({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False})], 2: [({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a'], ['b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': True})], 3: [({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a']], 'undo-available': False}), ({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False})], 4: [({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': True}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False})], 5: [({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False})]}
for index, (data, expected) in enumerate(fixtures[N]):
    check("contract fixture " + str(index), solve(data), 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)

meaning: Fixture-count band, not measured model difficulty

deps: stdlib

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

N = 1
observations = []
def solve(d):
    return {'undo-snapshot':(d['history'][-1] if d['history'] else d['current']), 'undo-tail':(d['history'][:-1]), 'redo-snapshot':(d['future'][0] if d['future'] else d['current']), 'branch-future':([]), 'noop-history':(d['history'] if set(d['next'])==set(d['current']) else d['history']+[d['current']]), 'undo-available':(bool(d['history']) and not d['applying'])}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = {1: [({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False})], 2: [({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a'], ['b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': True})], 3: [({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a']], 'undo-available': False}), ({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False})], 4: [({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': True}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False})], 5: [({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False})]}
for index, (data, expected) in enumerate(fixtures[N]):
    check("contract fixture " + str(index), solve(data), 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)

prompt:
A new criterion edit invalidates only the branched redo history is violated by the widget projection.

Each filter edit transaction records before and after snapshots. Undo/redo moves whole constraint snapshots and does not resurrect history after a new branch edit. This example checks: A new criterion edit invalidates only the branched redo history.

split: open-access


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

N = 1
observations = []
def solve(d):
    return {'undo-snapshot':(d['history'][-1] if d['history'] else d['current']), 'undo-tail':(d['history'][:-1]), 'redo-snapshot':(d['future'][0] if d['future'] else d['current']), 'branch-future':([] if d['new_edit'] else d['future']), 'noop-history':(d['history']+[d['current']]), 'undo-available':(bool(d['history']) and not d['applying'])}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = {1: [({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': False})], 2: [({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a'], ['b']], 'undo-available': True})], 3: [({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False})], 4: [({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': True})], 5: [({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False})]}
for index, (data, expected) in enumerate(fixtures[N]):
    check("contract fixture " + str(index), solve(data), 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)

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

N = 1
observations = []
def solve(d):
    return {'undo-snapshot':(d['history'][-1] if d['history'] else d['current']), 'undo-tail':(d['history'][:-1]), 'redo-snapshot':(d['future'][0] if d['future'] else d['current']), 'branch-future':([] if d['new_edit'] else d['future']), 'noop-history':(d['history'] if d['next']==d['current'] else d['history']+[d['current']]), 'undo-available':(bool(d['history']) and not d['applying'])}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = {1: [({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': False})], 2: [({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a'], ['b']], 'undo-available': True})], 3: [({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [], 'undo-available': False}), ({'history': [], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False})], 4: [({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a']], 'undo-available': True}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['b']], 'undo-available': True}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': False}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': True})], 5: [({'history': [], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': False}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x']], 'noop-history': [], 'undo-available': False}), ({'history': [['a']], 'future': [], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a']], 'undo-available': False}), ({'history': [['a']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['a'], 'undo-tail': [], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['a', 'b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['b', 'a'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [['x'], ['y']], 'noop-history': [['a'], ['b']], 'undo-available': False}), ({'history': [['a'], ['b']], 'future': [['x'], ['y']], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': True, 'applying': True}, {'undo-snapshot': ['b'], 'undo-tail': [['a']], 'redo-snapshot': ['x'], 'branch-future': [], 'noop-history': [['a'], ['b'], ['a', 'b']], 'undo-available': False}), ({'history': [], 'future': [], 'current': ['a', 'b'], 'next': ['c'], 'new_edit': False, 'applying': True}, {'undo-snapshot': ['a', 'b'], 'undo-tail': [], 'redo-snapshot': ['a', 'b'], 'branch-future': [], 'noop-history': [['a', 'b']], 'undo-available': False})]}
for index, (data, expected) in enumerate(fixtures[N]):
    check("contract fixture " + str(index), solve(data), 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)

prompt:
Order-only filter changes do not create undo transactions is violated by the widget projection.

Each filter edit transaction records before and after snapshots. Undo/redo moves whole constraint snapshots and does not resurrect history after a new branch edit. This example checks: Order-only filter changes do not create undo transactions.

split: open-access