From 7aa1f9dab11bedff0514b21c1ac7bf278e702fa2 Mon Sep 17 00:00:00 2001
From: Catalan Lover <catalanlover@protonmail.com>
Date: Sat, 19 Sep 2026 14:20:41 +0200
Subject: [PATCH] Add integration testing for policy expiry

---
 .../test/integration/policyExpiryTest.ts      | 137 ++++++++++++++++++
 1 file changed, 137 insertions(+)
 create mode 100644 apps/draupnir/test/integration/policyExpiryTest.ts

diff --git a/apps/draupnir/test/integration/policyExpiryTest.ts b/apps/draupnir/test/integration/policyExpiryTest.ts
new file mode 100644
index 00000000..31074fb7
--- /dev/null
+++ b/apps/draupnir/test/integration/policyExpiryTest.ts
@@ -0,0 +1,137 @@
+// SPDX-FileCopyrightText: 2026 Catalan Lover <catalanlover@protonmail.com>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+import { newTestUser } from "./clientHelper";
+import { Draupnir } from "../../src/Draupnir";
+import { DraupnirTestContext } from "./mjolnirSetupUtils";
+import {
+  DEFAULT_EXPIRY_DEBOUNCE_MS,
+  Membership,
+  PolicyRuleType,
+} from "@the-draupnir-project/matrix-protection-suite";
+import {
+  MatrixRoomReference,
+  StringRoomID,
+  StringUserID,
+} from "@the-draupnir-project/matrix-basic-types";
+
+async function createWatchedPolicyRoom(
+  draupnir: Draupnir
+): Promise<StringRoomID> {
+  const policyRoomID = (await draupnir.client.createRoom({
+    preset: "public_chat",
+  })) as StringRoomID;
+  (
+    await draupnir.protectedRoomsSet.watchedPolicyRooms.watchPolicyRoomDirectly(
+      MatrixRoomReference.fromRoomID(policyRoomID)
+    )
+  ).expect("Should be able to watch the new policy room");
+  return policyRoomID;
+}
+
+/**
+ * Polls `predicate` until it's true, rather than a fixed sleep since sync
+ * response times are too unpredictable for a fixed wait and we want the test
+ * to compromise between latency and reliability.
+ */
+async function waitForCondition(
+  predicate: () => boolean,
+  { timeoutMS, intervalMS = 200 }: { timeoutMS: number; intervalMS?: number }
+): Promise<void> {
+  const start = Date.now();
+  while (!predicate()) {
+    if (Date.now() - start > timeoutMS) {
+      throw new Error(`Timed out after ${timeoutMS}ms waiting for condition`);
+    }
+    await new Promise((resolve) => setTimeout(resolve, intervalMS));
+  }
+}
+
+// Expiry only drops the policy itself but instead triggers the policy removed code path.
+describe("Policy expiry test (MSC3908)", function () {
+  it(
+    "An expiring ban policy is applied, then dropped from the policy list once it expires",
+    async function (this: DraupnirTestContext) {
+      this.timeout(90000);
+      const draupnir = this.draupnir;
+      if (draupnir === undefined) {
+        throw new TypeError(`setup didn't run properly`);
+      }
+      const spammer = await newTestUser(this.config.homeserverUrl, {
+        name: { contains: "expiring-spam" },
+      });
+      const spammerUserID = (await spammer.getUserId()) as StringUserID;
+      const protectedRoomID = (await draupnir.client.createRoom({
+        invite: [spammerUserID],
+      })) as StringRoomID;
+      await spammer.joinRoom(protectedRoomID);
+      (
+        await draupnir.protectedRoomsSet.protectedRoomsManager.addRoom(
+          MatrixRoomReference.fromRoomID(protectedRoomID)
+        )
+      ).expect("Should be able to protect the room");
+
+      const policyRoomID = await createWatchedPolicyRoom(draupnir);
+      const policyRoomEditor = (
+        await draupnir.policyRoomManager.getPolicyRoomEditor(
+          MatrixRoomReference.fromRoomID(policyRoomID)
+        )
+      ).expect("Should be able to get a policy room editor");
+
+      const expiryDurationMS = 3000;
+      const expiry = Date.now() + expiryDurationMS;
+      (
+        await policyRoomEditor.banEntity(
+          PolicyRuleType.User,
+          spammerUserID,
+          "spam",
+          { expiry }
+        )
+      ).expect("Should be able to create a ban policy with an expiry");
+
+      const matchesEntity = () =>
+        draupnir.protectedRoomsSet.watchedPolicyRooms.currentRevision.allRulesMatchingEntity(
+          spammerUserID,
+          { type: PolicyRuleType.User }
+        ).length;
+      const matchesMember = () =>
+        draupnir.protectedRoomsSet.setPoliciesMatchingMembership.currentRevision.allRulesMatchingMember(
+          spammerUserID,
+          {}
+        ).length;
+
+      // wait for the policy to come down sync and be applied to the protected room.
+      await waitForCondition(() => matchesEntity() === 1, {
+        timeoutMS: 20000,
+      });
+      await waitForCondition(() => matchesMember() === 1, {
+        timeoutMS: 20000,
+      });
+      await waitForCondition(
+        () => {
+          const membershipRevision =
+            draupnir.protectedRoomsSet.setRoomMembership.getRevision(
+              protectedRoomID
+            );
+          return (
+            membershipRevision?.membershipForUser(spammerUserID)?.membership ===
+            Membership.Ban
+          );
+        },
+        { timeoutMS: 20000 }
+      );
+
+      // wait for the policy to expire: the remaining time until expiry, plus
+      // the scheduler's coalescing debounce, plus a generous timeout for sync
+      // and revision propagation against a possibly-busy shared homeserver.
+      const remainingUntilExpiry = Math.max(0, expiry - Date.now());
+      await waitForCondition(() => matchesEntity() === 0, {
+        timeoutMS: remainingUntilExpiry + DEFAULT_EXPIRY_DEBOUNCE_MS + 20000,
+      });
+      await waitForCondition(() => matchesMember() === 0, {
+        timeoutMS: 20000,
+      });
+    } as unknown as Mocha.AsyncFunc
+  );
+});