- the file was seven `test_*` functions that nothing called, plus a module-level
`print("ALL PASS")`: running it printed a verdict with zero assertions, and
`python3 -m unittest discover -s wizard-work/beam -p test_json_canonical.py`
collected 0 (rc 5, NO TESTS RAN) while the import still printed ALL PASS.
- the seven cells are now methods of one `unittest.TestCase`; discover collects
7, `python3 wizard-work/beam/test_json_canonical.py` runs 7 OK, and
`bash wizard-work/beam/CHECK` moves Ran 191 -> Ran 198, rc 0, OK.
- the ALL PASS print is deleted; there is no module-level verdict on import.
- cells bite, measured against a mutant battery (harness
/root/.hermes/profiles/volt/cache/scratch/q82/battery.py, rows in
mutant_results.json, one tree per mutant under .../q82/mut/). Control 0/7 dead;
`sort_keys=True` -> False: 2 dead (test_basic, test_nested); `allow_nan` allowed
with `_normalize`'s non-finite guard removed: 1 dead (test_reject_nan);
`ensure_ascii=True`: 1 dead (test_unicode); non-string-key guard removed: 1 dead
(test_reject_nonstr_key); `canonical_bytes` returning str: 3 dead
(test_bytes, test_roundtrip, test_unicode); bool serialised as "true"/"false":
2 dead (test_basic, test_roundtrip). All 7 cells have a named killer.
- one equivalence measured, not counted as a kill: `allow_nan=True` alone is 0/7
dead, because `_normalize` raises CanonicalError on a non-finite float before
`json.dumps` is reached. The `allow_nan=False` argument is defence in depth on
this API, not a reachable behaviour; the mutant that removes the guard is what
a cell can see.
CHECK: bash wizard-work/beam/CHECK
volt
07351026d4