fix: delete already closed client on closeSameClients (#929)

Co-authored-by: Daniel Lando <daniel.sorridi@gmail.com>

aedes.js

@@ -170,7 +170,13 @@ function Aedes (opts) {
     const clientId = packet.payload.toString()
 
     if (that.clients[clientId] && serverId !== that.id) {
-      that.clients[clientId].close(done)
+      if (that.clients[clientId].closed) {
+        // remove the client from the list if it is already closed
+        delete that.clients[clientId]
+        done()
+      } else {
+        that.clients[clientId].close(done)
+      }
     } else {
       done()
     }

test/events.js

@@ -221,3 +221,20 @@ test('Test backpressure aedes published function', function (t) {
     })
   })
 })
+
+test('clear closed clients when the same clientId is managed by another broker', function (t) {
+  t.plan(1)
+
+  const clientId = 'closed-client'
+  const broker = aedes()
+
+  // simulate a closed client on the broker
+  broker.clients[clientId] = { closed: true }
+
+  // simulate the creation of the same client on another broker of the cluster
+  broker.publish({ topic: '$SYS/anotherbroker/new/clients', payload: clientId }, () => {
+    t.equal(broker.clients[clientId], undefined) // check that the closed client was removed
+  })
+
+  t.teardown(broker.close.bind(broker))
+})