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]>

apps/api/tests/api-http.integration.ts

@@ -208,6 +208,29 @@ 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);
@@ -1349,7 +1372,7 @@ describe.sequential("live API — signup, sign-in, principal, sign-out", () => {
     await running.shutdown();
 
     await expect(fetch(origin, { signal: AbortSignal.timeout(1_000) })).rejects.toBeTruthy();
-    const remainingConnections = await activeConnectionCount(database.name);
+    const remainingConnections = await connectionsLeftAfterShutdown(database.name);
     expect(remainingConnections).toBe(0);
 
     await dropDatabase(database.name);
@@ -2230,7 +2253,7 @@ describe.sequential("live API — platform owner and delegated grant management"
 
   it("shuts down cleanly, closing the one shared pool", async () => {
     await running.shutdown();
-    const remainingConnections = await activeConnectionCount(database.name);
+    const remainingConnections = await connectionsLeftAfterShutdown(database.name);
     expect(remainingConnections).toBe(0);
     await dropDatabase(database.name);
   });
@@ -2837,7 +2860,7 @@ describe.sequential("live API — installed module permission end-to-end", () =>
 
   it("shuts down cleanly, then restarting with the module absent rejects new grants for its former permission, returns NOT_FOUND for its former route, while the historical grant remains listable", async () => {
     await running.shutdown();
-    const remainingConnections = await activeConnectionCount(database.name);
+    const remainingConnections = await connectionsLeftAfterShutdown(database.name);
     expect(remainingConnections).toBe(0);
     // Exactly one stop, matching the exactly-one register/start already asserted above.
     expect(recorder.events.filter((event) => event === "calendar:stop")).toHaveLength(1);

apps/api/tests/module-database.integration.ts

@@ -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();