Allow passing a cache to the queue

ts/session/sending/MessageQueue.ts

@@ -26,9 +26,9 @@ export class MessageQueue implements MessageQueueInterface {
   private readonly jobQueues: Map<PubKey, JobQueue> = new Map();
   private readonly pendingMessageCache: PendingMessageCache;
 
-  constructor() {
+  constructor(cache?: PendingMessageCache) {
     this.events = new EventEmitter();
-    this.pendingMessageCache = new PendingMessageCache();
+    this.pendingMessageCache = cache ?? new PendingMessageCache();
     void this.processAllPending();
   }
 
@@ -143,10 +143,12 @@ export class MessageQueue implements MessageQueueInterface {
           await jobQueue.addWithId(messageId, async () =>
             MessageSender.send(message)
           );
-          void this.pendingMessageCache.remove(message);
           this.events.emit('success', message);
         } catch (e) {
           this.events.emit('fail', message, e);
+        } finally {
+          // Remove from the cache because retrying is done in the sender
+          void this.pendingMessageCache.remove(message);
         }
       }
     });
@@ -173,7 +175,7 @@ export class MessageQueue implements MessageQueueInterface {
     }
 
     await this.pendingMessageCache.add(device, message);
-    await this.processPending(device);
+    void this.processPending(device);
   }
 
   private getJobQueue(device: PubKey): JobQueue {

ts/session/sending/PendingMessageCache.ts

@@ -93,12 +93,12 @@ export class PendingMessageCache {
     await this.saveToDB();
   }
 
-  private async loadFromDB() {
+  protected async loadFromDB() {
     const messages = await this.getFromStorage();
     this.cache = messages;
   }
 
-  private async getFromStorage(): Promise<Array<RawMessage>> {
+  protected async getFromStorage(): Promise<Array<RawMessage>> {
     const data = await getItemById('pendingMessages');
     if (!data || !data.value) {
       return [];
@@ -117,7 +117,7 @@ export class PendingMessageCache {
     });
   }
 
-  private async saveToDB() {
+  protected async saveToDB() {
     // For each plainTextBuffer in cache, save in as a simple Array<number> to avoid
     // Node issues with JSON stringifying Buffer without strict typing
     const encodedCache = [...this.cache].map(item => {