fix(05-review): IN-01 resolve actor display name in eventChangeDispatcher for D-02/D-03

apps/api/src/lib/eventChangeDispatcher.ts

@@ -15,9 +15,9 @@
  * Fire-and-forget: sync correctness does not depend on push success.
  */
 
-import { ne } from 'drizzle-orm'
+import { eq, ne } from 'drizzle-orm'
 import { db } from '../db/client.js'
-import { pushSubscriptions } from '../db/schema.js'
+import { users, pushSubscriptions } from '../db/schema.js'
 import { dispatchPush } from './pushDispatcher.js'
 
 // ── Types ────────────────────────────────────────────────────────────────────
@@ -71,32 +71,32 @@ export function isMeaningfulChange(change: EventChange): boolean {
 }
 
 /**
- * Builds the notification title for a change.
- * Actor name is omitted here (we don't have it from userId alone in the fast path);
- * the copy follows the D-02 spec using generic "A member" as fallback. For the
- * two-person household the non-actor will always be informed by the other member's
- * action, so the body context is sufficient.
+ * Builds the notification copy for a change (D-02/D-03).
  *
- * Note: actorName resolution (querying users table) is a future D-02 enhancement.
- * For MVP, use generic copy that still satisfies the acceptance criteria.
+ * @param change    - The detected calendar event change.
+ * @param actorName - Display name of the actor (D-03: named in every notification).
+ *                    Falls back to 'A family member' when the users row is absent.
  */
 function buildCopy(
   change: EventChange,
+  actorName: string,
 ): { notifTitle: string; notifBody: string; navigate: string } {
   const eventTitle = change.title ?? change.uid
 
   let notifTitle: string
   let notifBody: string
 
+  // D-02: event notifications show specifics — actor + title.
+  // D-03: name the actor in every change notification.
   if (change.operation === 'create') {
-    notifTitle = 'New calendar event'
+    notifTitle = `${actorName} added an event`
     notifBody = eventTitle
   } else if (change.operation === 'delete') {
-    notifTitle = 'Calendar event removed'
+    notifTitle = `${actorName} removed an event`
     notifBody = eventTitle
   } else {
     // update
-    notifTitle = 'Calendar event updated'
+    notifTitle = `${actorName} updated an event`
     notifBody = eventTitle
   }
 
@@ -128,13 +128,24 @@ export async function dispatchEventChange(
     return
   }
 
-  // D-13: query push_subscriptions from MariaDB only
-  // D-03: ne() filter excludes the actor at DB level; application-level filter
-  // below provides defence-in-depth (also makes the mock-based tests deterministic).
-  const allSubs = await db
-    .select()
-    .from(pushSubscriptions)
-    .where(ne(pushSubscriptions.userId, actorUserId))
+  // IN-01: resolve actor display name for D-02/D-03 notification copy.
+  // Runs in parallel with subscription query for minimal latency.
+  const [actorRows, allSubs] = await Promise.all([
+    db
+      .select({ displayName: users.displayName })
+      .from(users)
+      .where(eq(users.id, actorUserId))
+      .limit(1),
+    // D-13: query push_subscriptions from MariaDB only
+    // D-03: ne() filter excludes the actor at DB level; application-level filter
+    // below provides defence-in-depth (also makes the mock-based tests deterministic).
+    db
+      .select()
+      .from(pushSubscriptions)
+      .where(ne(pushSubscriptions.userId, actorUserId)),
+  ])
+
+  const actorName: string = actorRows[0]?.displayName ?? 'A family member'
 
   // D-03: additional application-level actor exclusion (defence-in-depth)
   const subs = allSubs.filter((s) => s.userId !== actorUserId)
@@ -143,7 +154,7 @@ export async function dispatchEventChange(
     return
   }
 
-  const { notifTitle, notifBody, navigate } = buildCopy(change)
+  const { notifTitle, notifBody, navigate } = buildCopy(change, actorName)
 
   // Fan out to all non-actor subscriptions (D-03 already enforced by ne() filter)
   for (const sub of subs) {