Export path escapes its base
sample_before.py:9
A parent-relative filename resolves outside the configured export directory. The fix resolves and constrains the candidate path.
Public capability proof · synthetic code
Every finding has a line, a reproduction, and a regression test.
This small Python review demonstrates the complete evidence chain: five intentional defects in a 32-line module, corrected code, and tests that lock in each remediation. It contains no client code and makes no client-result claims.
5reproduced findings
7/7regression tests passing
32reviewed source lines
0external runtime dependencies
Mutable default shares state
sample_before.py:12–15
Tags leak between otherwise independent calls. The fix allocates a new list for each default call.
Zero total crashes calculation
sample_before.py:20
An empty dataset raises an unexpected division error. The fix validates the total and reports a descriptive error.
Negative quantities pass validation
sample_before.py:25–27
Invalid negative values enter the domain unchanged. The fix rejects them immediately.
CSV fields are not escaped
sample_before.py:31
A comma inside a value changes the apparent column count. The fix delegates serialization to the standard CSV writer.
Run the evidence locally
python reproduce_findings.pypython -m unittest -qValidation is deterministic and reproducible. Service fulfillment uses AI assistance, automated checks, and human review; that disclosure is never hidden.