raise-coverage

Prompt file imported from mistersouls/tourillon (.github/prompts/raise-coverage.prompt.md). Fill in {{module}} before use. Copyright stays with the author.

Raise coverage for a module

Target module: {{module}}

Read .github/instructions/tests.instructions.md first.

Method

1. Measure the current state:

   uv run pytest --cov=<package> --cov-report=term-missing tests/<area>

   Note the specific uncovered line ranges — do not guess.
2. Read the module and list its behaviours, not its lines: success path, each error branch, retry/backoff, cancellation, shutdown, boundary conditions.
3. Write tests for the behaviours that are missing, preferring the order: error branches → cancellation/shutdown → boundaries → happy path (usually already covered).
4. Inject fakes at the port boundary (tourillon/core/ports/, tourlib/port/) rather than monkeypatching internals. If a module is untestable without monkeypatching, that is a design finding — report it.
5. Re-measure and confirm the new lines are genuinely exercised.

Rules

• No assertion-free tests, no tests that only call a function to move the number.
• Every test asserts observable behaviour: a return value, a raised exception, an emitted envelope kind, a stored record, a cancelled task.
• No fixed sleeps; bind to ephemeral ports; clean up tasks and temp dirs.
• Keep the full suite green and order-independent.

Priority areas

Per docs/backlog.md, the weakest areas are the peer pool, storage group, lifecycle, transfer planner, transport session, phi-accrual detector, gossip bootstrapper, and the whole tourclient package (which is not in the coverage gate at all).

Done when

uv run pytest passes, the targeted module's coverage improved measurably, and every new test maps to a named behaviour.