What tests am I missing?

You wrote tests and want to know what you didn't think of.

Here is my code and my existing tests. Tell me what is untested.

1. List behaviours the code has that no test asserts.
2. List edge cases missing entirely: boundaries, empty, null, error paths, concurrency.
3. Point out any test that would still pass if the code were broken — tests that assert the wrong thing.
4. Give me the five highest-value tests to add, as actual code.

Rank by likelihood of catching a real future bug, not by coverage percentage.

Code:


Tests:

Reviewing a change. Passes you run over a diff before it merges: correctness, security, concurrency, migrations.