[Miodec]

Summary

U1 from docs/specs/solid-monkeytype/roadmap.md. A single-row user collection replaces the mutable snapshot and its reactive mirror.

 src/ts/
 ├── collections/
+│   └── user.ts          # local-only row keyed by uid; getUser(), named writes
 ├── states/
-│   ├── snapshot.ts      # reactive mirror (deleted)
+│   └── last-result.ts   # last saved result signal, moved out of the mirror
 └── db.ts                # getSnapshot = getUser (read-only shim until U4); result-save orchestration

auth sign-in → loadUserData()   fetch user, map, insert row (throws, no row on failure)
auth sign-out → clearUser()
reads        → getUser()        reactive in Solid, plain read elsewhere; DeepReadonly
direct       → recordResult, addXp, setStreak, addBadge, setInboxUnreadSize,
               updateLbMemory, resetPersonalBests, setDiscordLink
optimistic   → updateName, unlinkDiscord, setStreakHourOffset, rateQuote,
               setQuoteFavorite, updateProfile   (apply now, roll back on failure)

On success, an optimistic action accepts the current row with its change re-applied, not the mutation's start-of-action copy. Otherwise a result save that lands while a name change is pending would get overwritten.

Intended deviations (added to the spec):

• Resetting PBs updates the PBs shown straight away. The reactive copy used to keep the old ones.
• User changes show at once and roll back if the request fails. They used to show only after the request.
• The account page's activity calendar updates after a test without a reload.

Evidence

• __tests__/collections/user.spec.ts (16 tests): every direct write, load success/failure, optimistic apply/rollback, a direct write during a pending action surviving, row without $synced/$origin
• Full frontend suite: 85 files / 1638 tests pass; oxlint --type-aware --type-check clean
• Browser (dev, signed in):
  • finished test → typing stats +1, activity padded to today, account calendar shows "1 test on Monday 26 Oct 2026"
  • edit profile → bio updates on the page, then restored
  • quote rating → stored in the row
  • favourite add (dev maxFavorites: 0) → server error shown, row rolled back
  • sign out → snapshot() undefined; sign back in → row reloaded

Merge Danger

Door: two-way

Blast Radius: account data

Every user-data writer and the sign-in load path changed. A missed field in the API→row mapping would show as a blank or stale value on account, profile, leaderboard or result screens. Readers go through the getSnapshot shim, so DeepReadonly turns any leftover mutation into a type error.

🤖 Generated with Claude Code

[Copilot]

🔵 Needs a closer look

It is a large two-way-door refactor of all user-data writers plus a subtle optimistic-action concurrency model, and it introduces a stale cross-user testActivityByYear cache that needs human verification.

1 open issue

• Module-level activity cache leaks stale data across users · New

What changed in this PR

Implements roadmap step U1: replaces the mutable Snapshot object and its reactive Solid mirror with a single-row, local-only TanStack DB collection keyed by uid (collections/user.ts). Reads go through one reactive getUser(); DB.getSnapshot becomes a read-only shim (= getUser, returning DeepReadonly<Snapshot>). Writers are split into named direct writes (xp, streak, typing stats, PBs/PB reset, lb memory, badges, inbox count, Discord link) and optimistic actions (name, Discord unlink, streak offset, quote rating, favourite quote, profile) that apply immediately and roll back on failure. The auth flow now calls loadUserData()/clearUser(), and the last-result signal moves to states/last-result.ts.

Changes:

• New collections/user.ts single-row collection with reactive mirror, direct writes, and reusable optimistic-action helper.
• db.ts slimmed to a getSnapshot = getUser shim; snapshot init/mutation code and the reactive mirror (states/snapshot.ts) deleted; all writers/readers migrated.
• Spec/roadmap updated (U1 marked done, intended behaviour deviations documented) and new user.spec.ts (16 tests) added.

File	Description
frontend/​src/​ts/​collections/​user.ts	New single-row collection: load/clear, direct writes, optimistic actions, PB/test-activity helpers.
frontend/​src/​ts/​db.ts	Removes snapshot state/mutators; getSnapshot shim; rebuilds calendar from plain data; module-level per-year cache.
frontend/​src/​ts/​states/​snapshot.ts	Deleted reactive mirror + mini-snapshot.
frontend/​src/​ts/​states/​last-result.ts	New home for the last-result signal.
frontend/​src/​ts/​constants/​default-snapshot.ts	testActivity is now plain TestActivity; drops calendar classes/isMiniSnapshot.
frontend/​src/​ts/​utils/​types.ts	Adds DeepReadonly<T>.
frontend/​src/​ts/​auth.tsx	Uses loadUserData()/clearUser() instead of initSnapshot/setSnapshot.
frontend/​src/​ts/​controllers/​quotes-controller.ts	Delegates favourite toggling to setQuoteFavorite.
frontend/​src/​ts/​components/​.../​*.tsx	Many components/modals switch reads to getUser() and writes to the new named actions.
frontend/​src/​ts/​collections/​{results,inbox,connections}.ts	Import moved/renamed user helpers.
frontend/​__tests__/​collections/​user.spec.ts	New coverage for load, direct writes, optimistic apply/rollback.
frontend/​__tests__/​__harness__/​app-shell.tsx	Uses userTesting.setUser instead of setSnapshot.
docs/​specs/​solid-monkeytype/​{spec,roadmap}.md	Documents U1 as done and the intended behaviour deviations.

_{Review effort: Balanced}