Merge branch 'task/17' into task/18

packages/core/src/preferences.ts

@@ -1,4 +1,5 @@
 import type { Db } from "@sttracker/db/db";
+import type { Executor } from "./history.ts";
 import { fromJson, toJson } from "@sttracker/db/json";
 import { nowIso } from "@sttracker/db/ids";
 import type { Visibility } from "@sttracker/db/schema";
@@ -16,15 +17,20 @@ export interface Preferences {
 
 export const DEFAULT_PREFERENCES: Preferences = { ratingScale: "5half", defaultVisibility: "private" };
 
-async function readRaw(db: Db, userId: string): Promise<Record<string, unknown>> {
-  const u = await db.k.selectFrom("users").select("preferences").where("id", "=", userId).executeTakeFirst();
+async function readRaw(k: Executor, userId: string, lock = false): Promise<Record<string, unknown>> {
+  let q = k.selectFrom("users").select("preferences").where("id", "=", userId);
+  if (lock) q = q.forUpdate();
+  const u = await q.executeTakeFirst();
   if (!u) throw new NotFoundError("user");
   return fromJson<Record<string, unknown>>(u.preferences, {});
 }
 
 /** The user's preferences; missing or invalid stored values fall back to the defaults. */
 export async function getPreferences(db: Db, userId: string): Promise<Preferences> {
-  const raw = await readRaw(db, userId);
+  return toPreferences(await readRaw(db.k, userId));
+}
+
+function toPreferences(raw: Record<string, unknown>): Preferences {
   return {
     ratingScale: (RATING_SCALES as readonly unknown[]).includes(raw.ratingScale) ? (raw.ratingScale as RatingScale) : DEFAULT_PREFERENCES.ratingScale,
     defaultVisibility: (VISIBILITIES as readonly unknown[]).includes(raw.defaultVisibility)
@@ -37,8 +43,12 @@ export async function getPreferences(db: Db, userId: string): Promise<Preference
 export async function updatePreferences(db: Db, userId: string, patch: Partial<Preferences>): Promise<Preferences> {
   if (patch.ratingScale !== undefined && !RATING_SCALES.includes(patch.ratingScale)) throw new ValidationError("ratingScale", "invalid");
   if (patch.defaultVisibility !== undefined && !VISIBILITIES.includes(patch.defaultVisibility)) throw new ValidationError("defaultVisibility", "invalid");
-  const raw = await readRaw(db, userId);
-  const next = { ...raw, ...Object.fromEntries(Object.entries(patch).filter(([, v]) => v !== undefined)) };
-  await db.k.updateTable("users").set({ preferences: toJson(next), updated_at: nowIso() }).where("id", "=", userId).execute();
-  return getPreferences(db, userId);
+  // Read-modify-write in one transaction, with the user row locked on Postgres (SQLite runs one
+  // connection), so concurrent updates of different keys don't drop each other.
+  return db.k.transaction().execute(async (tx) => {
+    const raw = await readRaw(tx, userId, db.dialect === "postgres");
+    const next = { ...raw, ...Object.fromEntries(Object.entries(patch).filter(([, v]) => v !== undefined)) };
+    await tx.updateTable("users").set({ preferences: toJson(next), updated_at: nowIso() }).where("id", "=", userId).execute();
+    return toPreferences(next);
+  });
 }