test(node): pin task list limit ceiling and default on the cursor handler - #572

Summary

Re-home of #405 (author: jialfaro), carried onto current main. The original clamp is already on main through the cursor-paginated list_tasks; this branch keeps the contributor history and adds the two regression pins main still lacks: the numeric ceiling (200) and the omitted-limit default (50).

Motivation & context

#399 reported that a negative limit on GET /api/v1/tasks returned 500 with a raw database error, and that the limit was unbounded. Both are already fixed on main: collect_visible_tasks clamps the requested limit to [0, 200] and negative-limit behavior is pinned by negative_limit_returns_empty. The residual value in the original PR is its test contract: explicit coverage that an over-ceiling limit returns at most 200 rows and that an omitted limit falls back to 50.

Kind of change

• Test coverage
• New commit(s) layered on a re-homed contributor branch (authorship preserved)

What changed

Contributor work (unchanged): the original clamp and tests written against the pre-cursor handler. The merge took main's side of tasks.rs wholesale, since the contributor's direct list_tasks clamp is superseded by collect_visible_tasks.

Maintainer commit:

• limit_ceiling_caps_at_200: seeds 201 tasks, requests limit=9223372036854775807 (i64::MAX), asserts count == 200.
• omitted_limit_uses_default_50: seeds 60 tasks, omits limit, asserts count == 50.

How a reviewer can verify

• cargo test -p gitlawb-node --bin gitlawb-node api::tasks::visible_tasks_tests covers the two new pins plus negative_limit_returns_empty.
• The clamp itself lives in collect_visible_tasks; this PR adds coverage, not behavior.

Before you request review

• cargo fmt --all -- --check clean
• cargo clippy --locked --workspace --all-targets -D warnings clean (pre-push gate ran on this head)
• Focused task tests run and pass on this head
• No secrets, credentials, or generated artifacts
• Contributor commits preserved unmodified (no rebase/amend/squash)

Protocol & signing impact

None: tests only, no behavior change.

Notes for reviewers

The implementation half of #405 is redundant on current main; the merge took main's side and this branch's delta is the two pins. Negative-limit coverage stays with the existing negative_limit_returns_empty. Supersedes #405.

Summary by CodeRabbit

• Tests
  • Added coverage confirming that task listings return no more than 200 rows for an extremely large limit, and return 50 rows when no limit is specified. These checks document the expected results for both limit-handling cases; no user-facing functionality changes are included.