Messages sent out of order after one message fails (#3131)

* Instead of skipping, bail out by clearing queue
* Allow additional status transition for events from QUEUED to NOT_SENT

Author: justjanne

spec/unit/scheduler.spec.ts

@@ -112,7 +112,7 @@ describe("MatrixScheduler", function () {
         expect(procCount).toEqual(2);
     });
 
-    it("should give up if the retryFn on failure returns -1 and try the next event", async function () {
+    it("should give up if the retryFn on failure returns -1", async function () {
         // Queue A & B.
         // Reject A and return -1 on retry.
         // Expect B to be tried next and the promise for A to be rejected.
@@ -139,19 +139,15 @@ describe("MatrixScheduler", function () {
             return new Promise<Record<string, boolean>>(() => {});
         });
 
-        const globalA = scheduler.queueEvent(eventA);
-        scheduler.queueEvent(eventB);
+        const queuedA = scheduler.queueEvent(eventA);
+        const queuedB = scheduler.queueEvent(eventB);
+        await Promise.resolve();
+        deferA.reject(new Error("Testerror"));
         // as queueing doesn't start processing synchronously anymore (see commit bbdb5ac)
         // wait just long enough before it does
-        await Promise.resolve();
+        await expect(queuedA).rejects.toThrow("Testerror");
+        await expect(queuedB).rejects.toThrow("Testerror");
         expect(procCount).toEqual(1);
-        deferA.reject({});
-        try {
-            await globalA;
-        } catch (err) {
-            await Promise.resolve();
-            expect(procCount).toEqual(2);
-        }
     });
 
     it("should treat each queue separately", function (done) {

src/models/room.ts

@@ -3380,7 +3380,7 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
 const ALLOWED_TRANSITIONS: Record<EventStatus, EventStatus[]> = {
     [EventStatus.ENCRYPTING]: [EventStatus.SENDING, EventStatus.NOT_SENT, EventStatus.CANCELLED],
     [EventStatus.SENDING]: [EventStatus.ENCRYPTING, EventStatus.QUEUED, EventStatus.NOT_SENT, EventStatus.SENT],
-    [EventStatus.QUEUED]: [EventStatus.SENDING, EventStatus.CANCELLED],
+    [EventStatus.QUEUED]: [EventStatus.SENDING, EventStatus.NOT_SENT, EventStatus.CANCELLED],
     [EventStatus.SENT]: [],
     [EventStatus.NOT_SENT]: [EventStatus.SENDING, EventStatus.QUEUED, EventStatus.CANCELLED],
     [EventStatus.CANCELLED]: [],

src/scheduler.ts

@@ -245,12 +245,7 @@ export class MatrixScheduler<T = ISendEventResponse> {
         // get head of queue
         const obj = this.peekNextEvent(queueName);
         if (!obj) {
-            // queue is empty. Mark as inactive and stop recursing.
-            const index = this.activeQueues.indexOf(queueName);
-            if (index >= 0) {
-                this.activeQueues.splice(index, 1);
-            }
-            debuglog("Stopping queue '%s' as it is now empty", queueName);
+            this.disableQueue(queueName);
             return;
         }
         debuglog("Queue '%s' has %s pending events", queueName, this.queues[queueName].length);
@@ -289,17 +284,32 @@ export class MatrixScheduler<T = ISendEventResponse> {
                         // give up (you quitter!)
                         debuglog("Queue '%s' giving up on event %s", queueName, obj.event.getId());
                         // remove this from the queue
-                        this.removeNextEvent(queueName);
-                        obj.defer.reject(err);
-                        // process next event
-                        this.processQueue(queueName);
+                        this.clearQueue(queueName, err);
                     } else {
                         setTimeout(this.processQueue, waitTimeMs, queueName);
                     }
                 },
             );
     };
 
+    private disableQueue(queueName: string): void {
+        // queue is empty. Mark as inactive and stop recursing.
+        const index = this.activeQueues.indexOf(queueName);
+        if (index >= 0) {
+            this.activeQueues.splice(index, 1);
+        }
+        debuglog("Stopping queue '%s' as it is now empty", queueName);
+    }
+
+    private clearQueue(queueName: string, err: unknown): void {
+        debuglog("clearing queue '%s'", queueName);
+        let obj: IQueueEntry<T> | undefined;
+        while ((obj = this.removeNextEvent(queueName))) {
+            obj.defer.reject(err);
+        }
+        this.disableQueue(queueName);
+    }
+
     private peekNextEvent(queueName: string): IQueueEntry<T> | undefined {
         const queue = this.queues[queueName];
         if (!Array.isArray(queue)) {