Three changes tightening the controller before opening the PR.
DROP MAGIC `extractItems` DEFAULTS
Controller used to auto-pull `data.items` / `data.albums` /
`data.artists` / `data.tracks` / `data.results` when no extractor
was supplied. Removed the fallback chain — every section now MUST
provide an explicit `extractItems(data) => array`. Validated at
register-time so misuse fails immediately, not silently on first
load against an endpoint that happened to return two arrays.
Cin standard: explicit > implicit. Magic key-grabbing could pick
the wrong one in edge cases (e.g. an endpoint returning both
`data.albums` and `data.results` would have grabbed albums when
the section actually wanted results).
All 10 existing controller call sites already passed explicit
extractors, so no migration churn — this is purely tightening the
contract for future sections.
REPLACE `renderItems` NULL-RETURN CONVENTION WITH `manualDom: true`
Your Albums and similar sections that delegate to existing renderers
that target a CHILD element of `contentEl` used to signal "leave the
container alone" by returning null/undefined from `renderItems`. That
convention is easy to confuse with an accidental missing-return error.
Replaced with an explicit `manualDom: true` config flag. Renderer is
still called for its side-effects, controller just skips the innerHTML
swap. Clearer intent at the call site. Updated `loadYourAlbums` to
use the new flag.
PIN THE CONTROLLER CONTRACT WITH JS TESTS
Added `tests/static/test_discover_section_controller.mjs` — 32 tests
covering the controller's lifecycle contract:
- Config validation (every required field, mutual exclusivity of
fetchUrl/data, type checks on contentEl)
- Happy-path fetch → parse → render
- Empty state (default empty render, hideWhenEmpty + sectionEl,
success=false treated as empty, custom isSuccess override)
- Stale state (fires when isStale returns true, wins over empty,
custom renderStale override)
- Error state (HTTP non-ok, fetch throws, showErrorToast fires
window.showToast, default off doesn't fire)
- No-fetch `data:` mode (value + function form, doesn't call fetch)
- manualDom mode (skips innerHTML swap, still calls renderer)
- Callable `fetchUrl` (resolved at load time, refresh re-resolves)
- Load coalescing (concurrent loads share one fetch)
- Refresh bypasses coalescing (re-fires fetch every call)
- Hook error containment (throwing renderer/onSuccess hooks don't
crash the controller)
Runs via Node's stable built-in `--test` runner — no package.json,
no jest/vitest dependency, no compile step. Just `node --test`.
Pytest wrapper at `tests/test_discover_section_controller_js.py`
shells out to node and asserts clean exit, so the JS tests fail
the regular pytest sweep if the controller contract drifts.
Skipped gracefully when node isn't available or is < 22.
Closes the "controller is a contract, pin it at the test boundary"
gap that Cin would have flagged on review.
VERIFICATION
- 2205/2205 full pytest suite green (was 2204 + 1 new wrapper)
- 32/32 `node --test` pass on the controller test file directly
- ruff clean
- node --check clean on all touched JS files
Broque Thomas