test: replace late portfolio sleep with started and done barriers (WealthLedger/backend#63)

test/tbank-local-reads.e2e-spec.ts

@@ -3,6 +3,7 @@ import type { Server } from 'node:http';
 import { INestApplication } from '@nestjs/common';
 import { JwtService } from '@nestjs/jwt';
 import { Test } from '@nestjs/testing';
+import assert from 'node:assert/strict';
 import { setTimeout as delay } from 'node:timers/promises';
 import request from 'supertest';
 
@@ -573,16 +574,30 @@ describe('local accounts and portfolio HTTP (SQLite)', () => {
     await put().expect(200);
     await seedMembership();
     const blocked = deferred<TbankPortfolio>();
-    upstream.getPortfolio.mockReturnValueOnce(blocked.promise);
-    await get('brokerage-accounts/account/portfolio').expect(200);
+    const started = deferred<void>();
+    upstream.getPortfolio.mockImplementationOnce(() => {
+      started.resolve();
+      return blocked.promise;
+    });
+    // Starts the real portfolio producer, the same path the hourly walk uses.
+    const late = await portfolioService.request(
+      'owner',
+      (await prisma.tbankConnection.findUniqueOrThrow({ where: { userId: 'owner' } })).revision,
+      'account',
+      true,
+    );
+    assert(late);
+    // The late upstream call must have begun before the connection is replaced.
+    await started.promise;
     await put().expect(200);
     await seedMembership();
     blocked.resolve({ positions: [] });
-    await delay(20);
+    // Barrier: the fenced producer's completion, not a timer.
+    await late.done;
+    expect(await prisma.tbankPortfolio.count()).toBe(0);
     const replaced = await get(
       'brokerage-accounts/account/portfolio?sync=observe',
     ).expect(200);
     expect((replaced.body as PortfolioResourceDto).data).toBeNull();
-    expect(await prisma.tbankPortfolio.count()).toBe(0);
   });
 });