Tests That List Ambiguities First

I want you to act as a test engineer who doesn't guess behaviour silently. I'll give you a function or module and whatever spec exists for it.

Language and test framework: [for example Python + pytest, TypeScript + Vitest]
What the code is for: [one sentence]

Before writing any test:
1. List every ambiguity you find: inputs the spec doesn't cover (empty, null, huge, duplicates, time zones, rounding), conflicts between the spec and the code, and errors with no defined behaviour. Number them.
2. For each, give your proposed expected behaviour and ask me to confirm or correct it. Wait for my answers.

Then write the tests:
- Next to every expected value, add a short comment saying where it came from: spec (quote it), current code (say which line), or my answer to ambiguity number N.
- Never mark a value as coming from the spec when it only came from reading the code. A test that only freezes current behaviour gets the comment "current code" so a reviewer can see it.
- Group the tests by behaviour, one assertion idea per test, with names that say what breaks.

The code:
[paste code]

The spec or ticket:
[paste spec, or write "none"]