[Miodec]

Summary

U1 + U4 from docs/specs/solid-monkeytype/roadmap.md. One Solid store holds the signed-in user and replaces the mutable snapshot, its reactive mirror and the DB.getSnapshot() reads. The "snapshot" naming is gone.

 src/ts/
 ├── collections/
+│   └── results.ts               # + NormalizedLocalResult (was SnapshotResult)
 ├── constants/
-│   ├── default-snapshot.ts      # Snapshot, SnapshotResult
+│   ├── user-data.ts             # UserData, getDefaultUserData
 ├── states/
-│   ├── snapshot.ts              # reactive mirror (deleted)
+│   ├── user.ts                  # the store: getUser(), named writes
+│   └── last-result.ts           # last saved result signal, moved out of the mirror
 ├── utils/
-│   └── snapshot-init-error.ts
+│   └── user-data-load-error.ts  # UserDataLoadError
 └── db.ts                        # getSnapshot/setSnapshot/initSnapshot deleted

auth sign-in → loadUserData()   fetch user, map, store it (throws UserDataLoadError, no user on failure)
             → userLoaded event (was snapshotUpdated)
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)
console      → window.user (was window.snapshot)

An optimistic action applies its change, sends the request, then applies the change again with the server's values. If the request fails, it rolls back only the fields it changed that nothing has written since. So a result save that lands while a name change is pending keeps its update, whether the name change succeeds or fails.

Why a store, not a collection (spec Q30): the collection had no sync source and still needed a mirror for synchronous reads.

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__/states/user.spec.ts (19 tests): load success/failure; every direct write; optimistic apply/rollback; a direct write made while an action is pending survives both success and failure; a newer action's change survives an older one failing; profile keeps the server's sanitized details
• Full frontend suite after merging master: 105 files / 1771 tests pass; oxlint --type-aware --type-check clean
• Browser (dev, signed in, collection version before the store swap):
  • 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 on the user
  • favourite add (dev maxFavorites: 0) → server error shown, change rolled back
  • sign out → user undefined; sign back in → user reloaded

Merge Danger

Door: two-way

Blast Radius: account data

Every user-data reader and writer changed, and so did the sign-in load path. A missed field in the API→user mapping would show as a blank or stale value on account, profile, leaderboard or result screens. getUser() returns DeepReadonly, so any mutation left outside the named writes is 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}

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[fehmer]

why is the cast needed?