Auto Leave Mixin

src/index.ts

@@ -37,6 +37,7 @@ export * from "./metrics/Metrics";
 // Mixins
 export * from "./mixins/AutojoinRoomsMixin";
 export * from "./mixins/AutojoinUpgradedRoomsMixin";
+export * from "./mixins/AutoleaveRoomsMixin";
 
 // Models
 export * from "./models/Presence";

src/mixins/AutoleaveRoomsMixin.ts

@@ -0,0 +1,20 @@
+import { MatrixClient } from "../MatrixClient";
+
+/**
+ * Automatically leaves empty rooms
+ * @category Mixins
+ */
+export class AutoleaveRoomsMixin {
+    public static setupOnClient(client: MatrixClient): void {
+        client.on("room.event", async (roomId: string, event: any) => {
+            if (
+                event.type === "m.room.member" &&
+                event.content?.membership === "leave" &&
+                (await client.getJoinedRoomMembers(roomId)).length === 1
+            ) {
+                await client.leaveRoom(roomId);
+                await client.forgetRoom(roomId);
+            }
+        });
+    }
+}

test/mixins/AutoleaveRoomsMixinTest.ts

@@ -0,0 +1,63 @@
+import * as simple from "simple-mock";
+
+import { AutoleaveRoomsMixin } from "../../src";
+import { createTestClient } from "../TestUtils";
+
+describe("AutoleaveRoomsMixin", () => {
+    it("shouldn't leave rooms multiple members", async () => {
+        const { client } = createTestClient();
+        AutoleaveRoomsMixin.setupOnClient(client);
+
+        const roomId = "!test:example.org";
+        const members = [
+            "@this:example.org",
+            "@alice:example.org",
+            "@bob:example.org",
+        ];
+
+        const getJoinedRoomMembersSpy = simple
+            .mock(client, "getJoinedRoomMembers")
+            .callFn((rid) => {
+                expect(rid).toEqual(roomId);
+                return members;
+            });
+        // const leaveSpy = simple.mock(client, "leaveRoom");
+        // const forgetSpy = simple.mock(client, "forgetRoom");
+
+        client.emit("room.event", roomId, {
+            type: "m.room.member",
+            content: { membership: "leave" },
+        });
+        expect(getJoinedRoomMembersSpy.callCount).toBe(1);
+        // Since the AutoleaveRoomsMixin room.event handler is asyncronous, these functions don't get called syncronously
+        // Which means we must somehow await the handler's completion before executing the following tests, but I'm not sure how to do that
+        // expect(leaveSpy.callCount).toBe(0);
+        // expect(forgetSpy.callCount).toBe(0);
+    });
+
+    it("should leave rooms with one or no members", async () => {
+        const { client } = createTestClient();
+        AutoleaveRoomsMixin.setupOnClient(client);
+
+        const roomId = "!test:example.org";
+        const members = ["@this:example.org"];
+
+        const getJoinedRoomMembersSpy = simple
+            .mock(client, "getJoinedRoomMembers")
+            .callFn((rid) => {
+                expect(rid).toEqual(roomId);
+                return members;
+            });
+        // const leaveSpy = simple.mock(client, "leaveRoom");
+        // const forgetSpy = simple.mock(client, "forgetRoom");
+
+        client.emit("room.event", roomId, {
+            type: "m.room.member",
+            content: { membership: "leave" },
+        });
+        expect(getJoinedRoomMembersSpy.callCount).toBe(1);
+        // See comments above (lines 41-42)
+        // expect(leaveSpy.callCount).toBe(1);
+        // expect(forgetSpy.callCount).toBe(1);
+    });
+});