feat: leave multiple rooms at once

Author: chojs23

packages/socket.io/lib/socket.ts

@@ -476,16 +476,30 @@ export class Socket<
    *   socket.leave("room1");
    *
    *   // leave multiple rooms
-   *   socket.leave("room1").leave("room2");
+   *   socket.leave(["room1", "room2"]);
    * });
    *
-   * @param {String} room
+   * @param {String|Array} rooms - room or array of rooms
    * @return a Promise or nothing, depending on the adapter
    */
-  public leave(room: string): Promise<void> | void {
-    debug("leave room %s", room);
+  public leave(rooms: Room | Array<Room>): Promise<void> | void {
+    const roomsSet = new Set(Array.isArray(rooms) ? rooms : [rooms]);
+    const promises: Array<Promise<void>> = [];
+
+    roomsSet.forEach((room) => {
+      debug("leave room %s", room);
+      const maybePromise = this.adapter.del(this.id, room);
+      if (
+        maybePromise &&
+        typeof (maybePromise as Promise<void>).then === "function"
+      ) {
+        promises.push(maybePromise as Promise<void>);
+      }
+    });
 
-    return this.adapter.del(this.id, room);
+    if (promises.length) {
+      return Promise.all(promises).then(() => undefined);
+    }
   }
 
   /**

packages/socket.io/test/socket.ts

@@ -941,6 +941,23 @@ describe("socket", () => {
     });
   });
 
+  it("should leave multiple rooms at once", (done) => {
+    const io = new Server(0);
+    const client = createClient(io, "/");
+
+    io.on("connection", (socket) => {
+      Promise.resolve(socket.join(["room1", "room2"]))
+        .then(() => Promise.resolve(socket.leave(["room1", "room2"])))
+        .then(() => {
+          const adapter = io.of("/").adapter;
+          expect(adapter.rooms.has("room1")).to.be(false);
+          expect(adapter.rooms.has("room2")).to.be(false);
+          success(done, io, client);
+        })
+        .catch(done);
+    });
+  });
+
   describe("onAny", () => {
     it("should call listener", (done) => {
       const io = new Server(0);