1 files changed, 57 insertions, 0 deletions
diff --git a/addons/mail/static/tests/systray/systray_messaging_menu_tests.js b/addons/mail/static/tests/systray/systray_messaging_menu_tests.js
index b31b12f15b3..610e689ae4a 100644
--- a/addons/mail/static/tests/systray/systray_messaging_menu_tests.js
+++ b/addons/mail/static/tests/systray/systray_messaging_menu_tests.js
@@ -920,5 +920,62 @@ QUnit.test('messaging menu widget: expand on thread preview', async function (as
     messagingMenu.destroy();
 });
 
+QUnit.test('messaging menu widget: click twice preview on slow message_fetch should open chat window once', async function (assert) {
+    // This test assumes that a condition for opening chat window is to
+    // successfully fetch messages beforehand.
+    assert.expect(1);
+
+    const self = this;
+    // Used to pause `message_fetch` after opening the messaging menu.
+    // This is necessary `message_fetch` on mailbox_inbox is required to
+    // display the previews.
+    let lockMessageFetch = false;
+    const messageFetchProm = testUtils.makeTestPromise();
+
+    const messagingMenu = new MessagingMenu();
+    testUtils.addMockEnvironment(messagingMenu, {
+        services: this.services,
+        data: this.data,
+        session: { partner_id: 1 },
+        async mockRPC(route, args) {
+            if (args.method === 'message_fetch' && lockMessageFetch) {
+                const _super = this._super.bind(this);
+                await messageFetchProm;
+                return _super(route, args);
+            }
+            if (args.method === 'channel_minimize') {
+                // called to detach thread in chat window
+                // simulate longpolling response with new chat window state
+                const channelInfo = {
+                    ...self.data['mail.channel'].records[0],
+                    is_minimized: true,
+                    state: 'open',
+                };
+                const notifications = [ [['myDB', 'res.partner'], channelInfo] ];
+                messagingMenu.call('bus_service', 'trigger', 'notification', notifications);
+            }
+            return this._super(...arguments);
+        },
+    });
+    await messagingMenu.appendTo($('#qunit-fixture'));
+
+    // Opening chat window 1st time from messaging menu (pending from `messageFetchDef`)
+    await testUtils.dom.click(messagingMenu.$('.dropdown-toggle'));
+    lockMessageFetch = true;
+    await testUtils.dom.click(messagingMenu.$('.o_mail_preview'));
+    // Click again on preview to open chat window
+    await testUtils.dom.click(messagingMenu.$('.dropdown-toggle'));
+    await testUtils.dom.click(messagingMenu.$('.o_mail_preview'));
+    messageFetchProm.resolve();
+    await testUtils.nextTick();
+
+    assert.containsOnce(
+        $,
+        '.o_thread_window',
+        "should only display a single chat window");
+
+    messagingMenu.destroy();
+});
+
 });
 });