Fix RealtimePresence#leave handling of PresenceMessage argument

RealtimePresence’s `enter*`, `update*` and `leave*` methods all
advertise themselves as accepting a PresenceMessage instance instead of
just a data object. This is the only way that ably-js supports passing
message extras to these methods.

However, `leave` does not handle a PresenceMessage argument properly; it
ends up nesting the PresenceMessage’s top-level fields inside the
payload’s `data` property.

To fix this, we change the argument handling to match that used by
`enter`.

Resolves #1465.

src/common/lib/client/realtimepresence.ts

@@ -223,10 +223,8 @@ class RealtimePresence extends Presence {
       'RealtimePresence.leaveClient()',
       'leaving; channel = ' + this.channel.name + ', client = ' + clientId
     );
-    const presence = PresenceMessage.fromValues({
-      action: 'leave',
-      data: data,
-    });
+    const presence = PresenceMessage.fromData(data);
+    presence.action = 'leave';
     if (clientId) {
       presence.clientId = clientId;
     }

test/realtime/presence.test.js

@@ -373,38 +373,69 @@ define(['ably', 'shared_helper', 'async', 'chai'], function (Ably, helper, async
 
     /*
      * Attach to channel, enter presence channel with extras and check received
-     * PresenceMessage has extras.
+     * PresenceMessage has extras. Then do the same for leaving presence.
      */
     it('presenceMessageExtras', function (done) {
       var clientRealtime = helper.AblyRealtime({ clientId: testClientId, tokenDetails: authToken });
-      var channelName = 'presenceMessageExtras';
+      var channelName = 'presenceEnterWithExtras';
       var clientChannel = clientRealtime.channels.get(channelName);
       var presence = clientChannel.presence;
-      presence.subscribe(
-        function (presenceMessage) {
-          try {
-            expect(presenceMessage.extras).to.deep.equal(
-              { headers: { key: 'value' } },
-              'extras should have headers "key=value"'
+
+      async.series(
+        [
+          function (cb) {
+            clientChannel.attach(cb);
+          },
+          // Test entering with extras
+          function (cb) {
+            presence.subscribe('enter', function (presenceMessage) {
+              try {
+                expect(presenceMessage.extras).to.deep.equal(
+                  { headers: { key: 'value' } },
+                  'extras should have headers "key=value"'
+                );
+              } catch (err) {
+                cb(err);
+                return;
+              }
+              cb();
+            });
+            presence.enter(
+              PresenceMessage.fromValues({
+                extras: { headers: { key: 'value' } },
+              })
             );
-          } catch (err) {
-            closeAndFinish(done, clientRealtime, err);
-            return;
-          }
-          closeAndFinish(done, clientRealtime);
-        },
-        function onPresenceSubscribe(err) {
+          },
+          // Test leaving with extras
+          function (cb) {
+            presence.subscribe('leave', function (presenceMessage) {
+              try {
+                expect(presenceMessage.extras).to.deep.equal(
+                  { headers: { otherKey: 'otherValue' } },
+                  'extras should have headers "otherKey=otherValue"'
+                );
+              } catch (err) {
+                cb(err);
+                return;
+              }
+              cb();
+            });
+            presence.leave(
+              PresenceMessage.fromValues({
+                extras: { headers: { otherKey: 'otherValue' } },
+              })
+            );
+          },
+        ],
+        function (err) {
           if (err) {
             closeAndFinish(done, clientRealtime, err);
             return;
           }
-          clientChannel.presence.enter(
-            PresenceMessage.fromValues({
-              extras: { headers: { key: 'value' } },
-            })
-          );
+          closeAndFinish(done, clientRealtime);
         }
       );
+
       monitorConnection(done, clientRealtime);
     });