feat(queue): add global:duplicated event when a duplicated is added (#2749)

lib/commands/addJob-6.lua

@@ -51,6 +51,7 @@ else
   jobId = ARGV[2]
   jobIdKey = ARGV[1] .. jobId
   if rcall("EXISTS", jobIdKey) == 1 then
+    rcall("PUBLISH", ARGV[1] .. "duplicated", jobId)
     return jobId .. "" -- convert to string
   end
 end

lib/queue.js

@@ -275,6 +275,7 @@ const Queue = function Queue(name, url, opts) {
       'repeat',
       'limiter',
       'drained',
+      'duplicated',
       'progress'
     ],
     key => {
@@ -416,6 +417,7 @@ Queue.prototype._setupQueueEventListeners = function() {
   const completedKey = this.keys.completed;
   const failedKey = this.keys.failed;
   const drainedKey = this.keys.drained;
+  const duplicatedKey = this.keys.duplicated;
 
   const pmessageHandler = (pattern, channel, message) => {
     const keyAndToken = channel.split('@');
@@ -437,6 +439,9 @@ Queue.prototype._setupQueueEventListeners = function() {
         }
         utils.emitSafe(this, 'global:stalled', message);
         break;
+      case duplicatedKey:
+        utils.emitSafe(this, 'global:duplicated', message);
+        break;
     }
   };
 
@@ -523,7 +528,7 @@ Queue.prototype._registerEvent = function(eventName) {
         .isRedisReady(this.eclient)
         .then(() => {
           const channel = this.toKey(_eventName);
-          if (['active', 'waiting', 'stalled'].indexOf(_eventName) !== -1) {
+          if (['active', 'waiting', 'stalled', 'duplicated'].indexOf(_eventName) !== -1) {
             return (this.registeredEvents[_eventName] = this.eclient.psubscribe(
               channel + '*'
             ));

test/test_queue.js

@@ -1097,6 +1097,27 @@ describe('Queue', () => {
       }
     });
 
+    describe('when job has been added again', () => {
+      it('emits duplicated event', async () => {
+        queue.process(
+          async () => {
+            await delay(50);
+            await queue.add({ foo: 'bar' }, { jobId: 'a1' });
+            await delay(50);
+          }
+        );
+  
+        await queue.add({ foo: 'bar' }, { jobId: 'a1' });
+    
+        await new Promise(resolve => {
+          queue.once('global:duplicated', (jobId) => {
+            expect(jobId).to.be.equal('a1');
+            resolve();
+          });
+        });
+      });
+    });
+
     it('process a job that updates progress', done => {
       queue.process((job, jobDone) => {
         expect(job.data.foo).to.be.equal('bar');