## Summary
- On unauthenticated pages (login), mocked object metadata was being
hydrated into the store with `readableFields` and `updatableFields`
attached. These derived arrays duplicate every field per object,
inflating `objectMetadataItems` in localStorage from ~70 KB to ~2 MB.
Combined with other metadata keys, this exceeded Safari's 5 MB quota and
caused `QuotaExceededError`, preventing real data from replacing mock
data on login.
- Extracted flat mock data into a dedicated file
(`generatedMockObjectMetadataItemsWithRelated.ts`) and use it for store
hydration, keeping the enriched version
(`generatedMockObjectMetadataItems`) only for tests.
- Completed `splitObjectMetadataItemWithRelated`'s contract by stripping
`readableFields` and `updatableFields` at runtime (not just via
TypeScript's `Omit`), matching the `FlatObjectMetadataItem` return type
that omits all four relational properties.
## Root cause
1. `MinimalMetadataLoadEffect` loads mocked metadata on unauthenticated
pages.
2. `generatedMockObjectMetadataItems` was produced by
`enrichObjectMetadataItemsWithPermissions`, which attaches
`readableFields` and `updatableFields` (full copies of the `fields`
array).
3. `splitObjectMetadataItemWithRelated` only destructured `fields` and
`indexMetadatas` — `readableFields`/`updatableFields` leaked into
`...objectProperties` at runtime because `Omit` is a compile-time-only
guard.
4. These bloated objects were written to localStorage, consuming ~2 MB
instead of ~70 KB.
5. On login, the intermediate state (old composite mock `current` + new
flat real `draft`) exceeded the 5 MB quota, causing a
`QuotaExceededError` deadlock.
## Test plan
- [ ] Open the app in a fresh Safari private window (empty localStorage)
- [ ] Verify the login page loads without errors
- [ ] Log in and verify metadata loads correctly
- [ ] Check `localStorage` size —
`metadataStoreState__objectMetadataItems` should be ~70 KB, not ~2 MB
- [ ] Run existing tests: `npx nx test twenty-front` — no regressions
from the mock data split
Made with [Cursor](https://cursor.com)
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Co-authored-by: Charles Bochet <charles@twenty.com>
