test(unit): add lightweight vitest coverage for auth duration and seq pagination utils

Fabric.Backend.Guild/src/messaging/messaging.controller.ts

@@ -17,6 +17,7 @@ import { Channel } from '../entities/channel.entity';
 import { Message } from '../entities/message.entity';
 import { IdempotencyRecord } from '../entities/idempotency-record.entity';
 import { EventsService } from '../events/events.service';
+import { clampLimit, computeNextExpectedSeq } from './pagination.util';
 
 const EDIT_WINDOW_MS = 15 * 60 * 1000;
 const DEFAULT_PAGE_LIMIT = 50;
@@ -214,11 +215,7 @@ export class MessagingController {
   ) {
     const from = seqFrom ? Number(seqFrom) : 1;
     const to = seqTo ? Number(seqTo) : Number.MAX_SAFE_INTEGER;
-    const requestedLimit = limit ? Number(limit) : DEFAULT_PAGE_LIMIT;
-    const safeLimit =
-      Number.isFinite(requestedLimit) && requestedLimit > 0
-        ? Math.min(requestedLimit, MAX_PAGE_LIMIT)
-        : DEFAULT_PAGE_LIMIT;
+    const safeLimit = clampLimit(limit, DEFAULT_PAGE_LIMIT, MAX_PAGE_LIMIT);
 
     if (from > to) {
       return {
@@ -251,15 +248,10 @@ export class MessagingController {
     const rows = await qb.limit(safeLimit).getMany();
     const items = rows.map((m) => this.toView(m));
 
-    let nextExpectedSeq = from;
-    for (const row of rows) {
-      if (row.seq > nextExpectedSeq) {
-        break;
-      }
-      if (row.seq === nextExpectedSeq) {
-        nextExpectedSeq += 1;
-      }
-    }
+    const nextExpectedSeq = computeNextExpectedSeq(
+      from,
+      rows.map((row) => row.seq),
+    );
 
     return {
       items,