feat(tests): enhance test database setup and cleanup for improved isolation and performance

test/setup.ts

@@ -1,39 +1,52 @@
-import { beforeAll, afterAll, afterEach, vi } from 'vitest';
-import { testDatabase } from './helpers/database';
+// IMPORTANT: this file runs before each test file's imports execute.
+// We rewrite DATABASE_URL and REDIS_URL here so per-worker isolation is
+// applied before any service module constructs a Prisma/Redis client.
+
 import dotenv from 'dotenv';
 import path from 'path';
+import {afterAll, afterEach, beforeAll, vi} from 'vitest';
 
-// Load environment variables from root .env file
-dotenv.config({ path: path.resolve(__dirname, '../.env') });
+dotenv.config({path: path.resolve(__dirname, '../.env')});
+
+// Vitest assigns each worker a 1-based pool id; defaults to "1" for single-worker runs.
+const workerId = process.env.VITEST_POOL_ID || '1';
+
+if (process.env.DATABASE_URL) {
+  const url = new URL(process.env.DATABASE_URL);
+  const baseDb = url.pathname.replace(/^\//, '') || 'plunk_test';
+  url.pathname = `/${baseDb}_w${workerId}`;
+  process.env.DATABASE_URL = url.toString();
+  // Mirror onto DIRECT_DATABASE_URL so prisma migrate uses the same worker DB.
+  if (process.env.DIRECT_DATABASE_URL) {
+    const direct = new URL(process.env.DIRECT_DATABASE_URL);
+    direct.pathname = `/${baseDb}_w${workerId}`;
+    process.env.DIRECT_DATABASE_URL = direct.toString();
+  }
+}
+
+if (process.env.REDIS_URL) {
+  const url = new URL(process.env.REDIS_URL);
+  url.pathname = `/${(parseInt(workerId, 10) - 1) % 16}`;
+  process.env.REDIS_URL = url.toString();
+}
+
+process.env.NODE_ENV = 'test';
+process.env.JWT_SECRET = process.env.JWT_SECRET || 'test-jwt-secret-key-for-testing';
+
+// Static import is safe: database.ts only reads env in initialize(), which runs
+// in beforeAll — well after the env mutations above.
+import {testDatabase} from './helpers/database';
 
-// Global test setup
 beforeAll(async () => {
-  // Initialize test database
   await testDatabase.initialize();
 });
 
 afterEach(async () => {
-  // Clear all mocks first
   vi.clearAllMocks();
-
-  // Restore real timers
   vi.useRealTimers();
-
-  // Clean up database after each test
-  // This must be last to ensure proper cleanup order
   await testDatabase.cleanup();
-
-  // Force garbage collection hint (if available in test environment)
-  if (global.gc) {
-    global.gc();
-  }
 });
 
 afterAll(async () => {
-  // Disconnect from database
   await testDatabase.disconnect();
 });
-
-// Set test environment variables
-process.env.NODE_ENV = 'test';
-process.env.JWT_SECRET = process.env.JWT_SECRET || 'test-jwt-secret-key-for-testing';