[SDK-3883] Remove ability to pass array of event names to EventEmitter.prototype.once

src/common/lib/client/realtimechannel.ts

@@ -165,9 +165,11 @@ class RealtimeChannel extends Channel {
       // Ignore 'attaching' -- could be just due to to a resume & reattach, should not
       // call back setOptions until we're definitely attached with the new options (or
       // else in a terminal state)
-      this._allChannelChanges.once(
+      const self = this;
+      this._allChannelChanges.on(
         ['attached', 'update', 'detached', 'failed'],
-        function (this: { event: string }, stateChange: ConnectionStateChange) {
+        function listener(this: { event: string }, stateChange: ConnectionStateChange) {
+          self._allChannelChanges.off(listener);
           switch (this.event) {
             case 'update':
             case 'attached':

src/common/lib/util/eventemitter.ts

@@ -237,14 +237,14 @@ class EventEmitter {
    * @param event the name of the event to listen to
    * @param listener the listener to be called
    */
-  once(event?: string | string[] | null, listener?: Function): void;
+  once(event?: string | null, listener?: Function): void;
 
   once(...args: unknown[]): void | Promise<void> {
     const argCount = args.length;
     if ((argCount === 0 || (argCount === 1 && typeof args[0] !== 'function')) && Platform.Config.Promise) {
       const event = args[0];
       return new Platform.Config.Promise((resolve) => {
-        this.once(event as string | string[] | null, resolve);
+        this.once(event as string | null, resolve);
       });
     }
 
@@ -256,21 +256,6 @@ class EventEmitter {
         throw new Error('EventEmitter.once(): Invalid arguments:' + Platform.Config.inspect(args));
       }
       this.anyOnce.push(secondArg);
-    } else if (Utils.isArray(firstArg)) {
-      const self = this;
-      const listenerWrapper = function (this: any) {
-        const innerArgs = Array.prototype.slice.call(arguments);
-        Utils.arrForEach(firstArg, function (eventName) {
-          self.off(eventName, listenerWrapper);
-        });
-        if (typeof secondArg !== 'function') {
-          throw new Error('EventEmitter.once(): Invalid arguments:' + Platform.Config.inspect(args));
-        }
-        secondArg.apply(this, innerArgs);
-      };
-      Utils.arrForEach(firstArg, function (eventName) {
-        self.on(eventName, listenerWrapper);
-      });
     } else {
       if (typeof firstArg !== 'string') {
         throw new Error('EventEmitter.once(): Invalid arguments:' + Platform.Config.inspect(args));

test/realtime/event_emitter.test.js

@@ -342,31 +342,6 @@ define(['shared_helper', 'chai'], function (helper, chai) {
       closeAndFinish(done, realtime);
     });
 
-    it('arrayOfEventsWithOnce', function (done) {
-      var realtime = helper.AblyRealtime({ autoConnect: false }),
-        callbackCalled = 0,
-        eventEmitter = realtime.connection;
-
-      var callback = function (arg) {
-        callbackCalled += 1;
-        expect(arg).to.equal('expected');
-      };
-
-      try {
-        callbackCalled = 0;
-        eventEmitter.once(['a', 'b', 'c'], callback);
-        eventEmitter.emit('a', 'expected');
-        eventEmitter.emit('b', 'wrong');
-        eventEmitter.emit('c', 'wrong');
-        expect(callbackCalled).to.equal(1, 'listener called back only once, for the first event emitted');
-      } catch (err) {
-        closeAndFinish(done, realtime, err);
-        return;
-      }
-
-      closeAndFinish(done, realtime);
-    });
-
     /* check that listeners added in a listener cb are not called during that
      * emit instance */
     it('listenerAddedInListenerCb', function (done) {
@@ -481,19 +456,6 @@ define(['shared_helper', 'chai'], function (helper, chai) {
             closeAndFinish(done, realtime, err);
           });
         });
-
-        it('arrayOfEventsWithOnce', function (done) {
-          var realtime = helper.AblyRealtime({ autoConnect: false }),
-            eventEmitter = realtime.connection;
-
-          const p = eventEmitter.once(['a', 'b', 'c']);
-          eventEmitter.emit('b');
-          p.then(function () {
-            closeAndFinish(done, realtime);
-          }).catch(function (err) {
-            closeAndFinish(done, realtime, err);
-          });
-        });
       });
     }
   });