PR #144 (`31da384`, 2026-06-13) shipped a `ReferenceError: useFocusTrap
is not defined` to production because the flat ESLint config did NOT
enable the core `no-undef` rule — only `react/jsx-no-undef` (which
catches undefined JSX components, not plain JS identifier references).
This PR closes that gap, narrowly.
## What changes
- `eslint.config.mjs`: enable `no-undef: 'error'` for source files +
define the ~40 browser / Node / Vitest globals the rule needs.
Hand-curated globals list (rejected pulling in the `globals` npm
package for one config block).
- 3 latent bugs surfaced + fixed (NOT silenced with disables):
| Site | Bug | Fix |
|------|-----|-----|
| `components/CollectionPageView.js:238` | `onClick={toggleFavorite}` — fn defined in `lib/use-collection-view.js:269` (collection-level favorite) but missing from the hook's `return {}` | Added to hook return + component destructure |
| `components/CollectionPageView.js:532` | `onTogglePublic={togglePublic}` — same pattern, fn at line 315 of the hook | Same shape: hook return + destructure |
| `components/ShareModal.js:99` | `fetchInvitedUsers()` scoped inside the useEffect body but called from `handleInvite` outside | Extracted to component scope via `useCallback`; effect dep array updated |
Bugs 1 + 2 broke the "Favorite collection" button and the public-toggle
in the Share modal on the collection-detail page. Bug 3 broke the
"refresh invitee list" path after a successful invite. None had been
flagged because the operator hadn't exercised those exact flows since
the relevant hooks were last refactored.
- `components/ShareModal.js`: also adds an eslint-disable for
`react-hooks/set-state-in-effect` on the moved `fetchInvitedUsers()`
call. Matches the canonical pattern in `pages/profile.js:90` —
async fetch; setState fires post-resolve, not synchronously to the
effect body.
## Why not pull in @eslint/js/recommended wholesale?
The recommended bundle also enables `no-unused-vars`,
`no-prototype-builtins`, `no-empty`, `no-cond-assign`, and ~10 others
— each would generate dozens of pre-existing violations on this
codebase. The right rule-by-rule sweep is the deferred
`adopt-eslint-recommended-set` convoy. This PR is scoped to the one
rule that would have caught PR #144's bug class.
## Test plan
- [x] `npm run lint` — clean (1 pre-existing unrelated warning on
`CollectionsPageView.js`'s `eslint-disable` directive — out of
scope)
- [x] `npm run test:run` — 25 files / 123 tests pass
- [ ] CI on this PR
- [ ] Post-merge: exercise the three formerly-broken paths (favorite a
collection from its detail page; toggle a collection public via
Share modal; invite a user and confirm the invitee list refreshes)
## Convoy doc
`.convoys/enable-no-undef-eslint-rule.md` documents the surfaced bugs,
D1 (no-undef only vs recommended bundle), D2 (hand-curated globals vs
`globals` package), risks, and acceptance.
Co-authored-by: Cursor <cursoragent@cursor.com>
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