fix: avoiding duplicate discovery tasks

Added locking on the vertex to avoid duplicating a task due to racing. Also catching and throwing the singleton reason, so we don't get any errors on tasks that were canceled for this reason.

src/discovery/Discovery.ts

@@ -109,6 +109,8 @@ class Discovery {
         await this.startDiscoveryForVertex(vertex);
         return;
       }
+      // Aborting a duplicate task is not an error
+      if (e === abortSingletonTaskReason) return;
       throw e;
     }
   };
@@ -451,6 +453,10 @@ class Discovery {
       );
     }
 
+    // Locking on vertex to avoid duplicates
+    await tran.lock(
+      [this.constructor.name, this.discoverVertexHandlerId, vertex].join(''),
+    );
     // Check if task exists
     let taskExists = false;
     for await (const task of this.taskManager.getTasks(
@@ -467,12 +473,15 @@ class Discovery {
       task.cancel(abortSingletonTaskReason);
     }
     // Create a new task if none exists
-    await this.taskManager.scheduleTask({
-      handlerId: this.discoverVertexHandlerId,
-      parameters: [vertex],
-      path: [this.constructor.name, this.discoverVertexHandlerId, vertex],
-      lazy: true,
-    });
+    await this.taskManager.scheduleTask(
+      {
+        handlerId: this.discoverVertexHandlerId,
+        parameters: [vertex],
+        path: [this.constructor.name, this.discoverVertexHandlerId, vertex],
+        lazy: true,
+      },
+      tran,
+    );
   }
 
   /**

tests/discovery/Discovery.test.ts

@@ -212,10 +212,8 @@ describe('Discovery', () => {
     const [, claimEncoded] = await nodeB.sigchain.addClaim(identityClaim);
     const claim = claimsUtils.decodeClaim(claimEncoded);
     await testProvider.publishClaim(identityId, claim);
-    logger.setLevel(LogLevel.INFO);
   });
   afterEach(async () => {
-    logger.setLevel(LogLevel.WARN);
     await taskManager.stopProcessing();
     await taskManager.stopTasks();
     await nodeA.stop();