test(api): let a shutdown's closed connections leave pg_stat_activity

Four integration tests shut the API down and immediately count the database's rows in pg_stat_activity, expecting zero. PostgreSQL ends a backend asynchronously: pool.end() resolves once the client side has closed, and the server can still list that backend for a moment. On a loaded runner an immediate count saw one, failing migration-smoke on a docs-only PR (Ekklesia CI run #238, module-database.integration.ts:764, "expected 1 to be +0"). Reproduced against postgres:18.4-alpine3.24 limited to 0.05 CPU: after pool.end() resolved, the backend was still listed in 7 of 300 trials, and gone about a millisecond later. The checks now wait up to 3 s for the count to reach zero. A connection that is genuinely left open is still caught: an idle pooled client stays listed for pg-pool's 10 s idle timeout, far past the deadline. Co-Authored-By: Claude Opus 5.5 <[email protected]>
2026-10-13 23:13:21 -05:00
parent 63fda0f8d6
commit f2fc069e66
2 changed files with 50 additions and 4 deletions
@@ -195,6 +195,29 @@ async function activeConnectionCount(databaseName: string): Promise<number> {
  }
 }

+/** How long a shutdown's closed connections may take to leave `pg_stat_activity`. Far below pg's
+ * 10 s idle timeout, so a connection that is genuinely still open is still caught. */
+const SHUTDOWN_SETTLE_MS = 3_000;
+
+/**
+ * The connections left on `databaseName` once a shutdown has had a moment to land.
+ *
+ * PostgreSQL ends a backend asynchronously: `pool.end()` resolves once the client side has closed,
+ * and the server can still list that backend for a moment afterwards. On a loaded CI runner that
+ * moment was long enough for an immediate count to see one. So this waits, briefly, for the count to
+ * reach zero; a leaked pooled client would stay idle and listed far past the deadline.
+ */
+async function connectionsLeftAfterShutdown(databaseName: string): Promise<number> {
+  const deadline = Date.now() + SHUTDOWN_SETTLE_MS;
+  for (;;) {
+    const count = await activeConnectionCount(databaseName);
+    if (count === 0 || Date.now() >= deadline) {
+      return count;
+    }
+    await new Promise((resolve) => setTimeout(resolve, 50));
+  }
+}
+
 async function createDisposableDatabase(label: string): Promise<{ name: string; url: string }> {
  const name = makeDatabaseName(label);
  await createDatabase(name);
@@ -760,7 +783,7 @@ describe.sequential("live API — module database access through ModuleRuntimeSe

    await running.shutdown();

-    const remainingConnections = await activeConnectionCount(database.name);
+    const remainingConnections = await connectionsLeftAfterShutdown(database.name);
    expect(remainingConnections).toBe(0);

    const eventsAfterShutdown = readRecorder();