fix(test): ensure Migration indexes exist on per-worker DBs when migrations pre-warmed (#3561)

* fix(test): ensure Migration indexes exist on per-worker DBs when migrations pre-warmed

When DEVKIT_MIGRATIONS_RAN=1 (set by globalSetup), bootstrap() skipped
migrations.run() entirely — but jest workers operate on JEST_WORKER_ID-suffixed
DBs that never had indexes created. The unique index on Migration.name was only
present on the base DB, causing duplicate-rejection assertions
(migrations.integration.tests.js) to fail on worker DBs.

Fix: in the migrationsAlreadyRan branch, call migrations.ensureMigrationIndexes()
(which delegates to Migration.syncIndexes()) to recreate the unique index on the
worker DB without re-running the migration files themselves.

Backported from trawl_node commit ce541f0f72d3 (trawl_node#1075).

* fix(test): clarify ensureMigrationIndexes comment to cover --runInBand case

Author: PierreBrisorgueil

lib/app.js

@@ -76,6 +76,15 @@ const bootstrap = async () => {
       process.env.NODE_ENV === 'test' && process.env.DEVKIT_MIGRATIONS_RAN === '1';
     if (!migrationsAlreadyRan) {
       await migrations.run();
+    } else {
+      // globalSetup already ran migrations on a DB that may differ from the one
+      // this suite connects to (e.g. a per-worker DB identified by JEST_WORKER_ID,
+      // or the same base DB when running with --runInBand). Ensure the unique
+      // index on Migration.name exists in the currently-connected DB so
+      // duplicate-rejection works correctly (e.g. migrations.integration.tests.js).
+      // On the base DB this is a harmless no-op — indexes already exist after
+      // globalSetup ran migrations.run().
+      await migrations.ensureMigrationIndexes();
     }
     app = await startExpress();
   } catch (e) {