Assessment Solutions and Scoring
Preserve the independent attempt. Equivalent supported arguments are acceptable; names of patterns alone are insufficient.
A01 / C01
No. A generator that yields one row then raises leaves a header in the baseline and no header in the changed version. Identical successful totals do not establish failure-trace preservation.
Repair: revisit the mapped practice task, then defend a fresh case without this key.
A02 / C02
Per-line rounding yields 1+1+1=3 cents. Aggregate rounding of 0.015 yields 2 cents. At now 9, the baseline discount gives 2.7 cents rounded to 3. Equality must not receive the discount; use a larger total to expose that policy difference.
Repair: revisit the mapped practice task, then defend a fresh case without this key.
A03 / C03
Import-time capture becomes stale and moves acquisition. Supply a callable and invoke it once at the original point, or keep production acquisition in a wrapper at that point. Test changing time during iteration and clock failures.
Repair: revisit the mapped practice task, then defend a fresh case without this key.
A04 / C04
Bisect can locate the first failing revision, subject to a usable test and the usual history assumptions. It does not diagnose edits within a commit. Preserve baseline observations and mark the intended rounding difference; separate commits in one PR are compatible with two-hats reasoning.
Repair: revisit the mapped practice task, then defend a fresh case without this key.
A05 / C05
The rewrite evaluates next twice. Store its result once in a fresh local and reuse it, preserving evaluation order and exceptions. Pure stable arguments would need different reasoning.
Repair: revisit the mapped practice task, then defend a fresh case without this key.
A06 / C06
The baseline raises KeyError for X; eager conversion raises ValueError first. Retain the quantity token until after lookup, or classify the changed precedence as an intentional validation migration.
Repair: revisit the mapped practice task, then defend a fresh case without this key.
A07 / C07
Sequential guards and left-to-right short-circuit OR can log only A and return the same result. Eager helper arguments evaluate B and raise. Side effects require trace reasoning; their presence alone does not prove OR changes semantics.
Repair: revisit the mapped practice task, then defend a fresh case without this key.
A08 / C08
The APIs lack shared state authority. Delegate both to one store under the same coordinate/value contract and interleave both directions in tests. This does not establish a safe concurrent database migration.
Repair: revisit the mapped practice task, then defend a fresh case without this key.
A09 / C09
Acknowledgement loss leaves an unknown effect. Fallback can duplicate it. A retry policy needs durable deduplication or authoritative reconciliation with defined key scope, retention and payload rules; a flag or key parameter alone is insufficient.
Repair: revisit the mapped practice task, then defend a fresh case without this key.
A10 / C10
Inventory external and delayed callers, supported versions and deprecation policy. Establish whether old readers understand new records and whether writes/side effects are reversible. Retain a facade or roll forward when necessary; passing local tests is insufficient.
Repair: revisit the mapped practice task, then defend a fresh case without this key.