Add a browser test for tab group drag issue

browser/ui/views/tabs/tab_drag_controller_browsertest.cc

@@ -0,0 +1,71 @@
+/* Copyright (c) 2024 The Brave Authors. All rights reserved.
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#include "chrome/browser/ui/views/tabs/tab_drag_controller.h"
+
+#include "brave/browser/ui/tabs/features.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_tabstrip.h"
+#include "chrome/browser/ui/views/tabs/tab_strip.h"
+#include "chrome/test/base/in_process_browser_test.h"
+#include "chrome/test/base/ui_test_utils.h"
+#include "content/public/test/browser_test.h"
+
+class TabDragControllerTest : public InProcessBrowserTest {
+ public:
+  ~TabDragControllerTest() override = default;
+
+  TabDragControllerTest() {
+    scoped_feature_list_.InitAndEnableFeature(tabs::features::kBraveSplitView);
+  }
+
+ protected:
+  void AppendTab(Browser* browser) {
+    chrome::AddTabAt(browser, GURL(), -1, true);
+  }
+
+  tab_groups::TabGroupId AddTabToNewGroup(Browser* browser, int tab_index) {
+    return browser->tab_strip_model()->AddToNewGroup({tab_index});
+  }
+
+  TabStrip* GetTabStripForBrowser(Browser* browser) {
+    BrowserView* browser_view = BrowserView::GetBrowserViewForBrowser(browser);
+    return browser_view->tabstrip();
+  }
+
+ private:
+  base::test::ScopedFeatureList scoped_feature_list_;
+};
+
+// Browser test for https://github.com/brave/brave-browser/issues/39486
+IN_PROC_BROWSER_TEST_F(TabDragControllerTest, DragGroupHeaderToSeparateWindow) {
+  ASSERT_TRUE(browser()->tab_strip_model()->SupportsTabGroups());
+  tab_groups::TabGroupId group = AddTabToNewGroup(browser(), 0);
+  AppendTab(browser());
+
+  TabStrip* tab_strip = GetTabStripForBrowser(browser());
+  EXPECT_EQ(tab_strip->tab_at(0)->group().value(), group);
+  EXPECT_EQ(tab_strip->tab_at(1)->group(), std::nullopt);
+
+  TabGroupHeader* tab_group_header = tab_strip->group_header(group);
+  gfx::Point tab_group_header_center(tab_group_header->width() / 2,
+                                     tab_group_header->height() / 2);
+  const ui::MouseEvent mouse_pressed_event(
+      ui::EventType::kMousePressed, tab_group_header_center,
+      tab_group_header_center, base::TimeTicks(), ui::EF_LEFT_MOUSE_BUTTON,
+      ui::EF_LEFT_MOUSE_BUTTON);
+  tab_strip->StopAnimating(true);
+  tab_strip->MaybeStartDrag(tab_group_header, mouse_pressed_event,
+                            tab_strip->GetSelectionModel());
+
+  static const int kDragDistance = 20;
+  gfx::Point tab_group_drag_point(tab_group_header->width() + kDragDistance,
+                                  tab_group_header->height() + kDragDistance);
+  ui::MouseEvent mouse_dragged_event(
+      ui::EventType::kMouseDragged, tab_group_drag_point, tab_group_drag_point,
+      base::TimeTicks(), ui::EF_LEFT_MOUSE_BUTTON, 0);
+  std::ignore = tab_strip->ContinueDrag(tab_group_header, mouse_dragged_event);
+  tab_strip->EndDrag(EndDragReason::END_DRAG_COMPLETE);
+}

test/BUILD.gn

@@ -1114,6 +1114,7 @@ test("brave_browser_tests") {
       "//brave/browser/ui/views/omnibox/omnibox_autocomplete_browsertest.cc",
       "//brave/browser/ui/views/profiles/brave_profile_menu_view_browsertest.cc",
       "//brave/browser/ui/views/tabs/brave_tab_context_menu_contents_browsertest.cc",
+      "//brave/browser/ui/views/tabs/tab_drag_controller_browsertest.cc",
       "//brave/browser/ui/views/tabs/vertical_tab_strip_browsertest.cc",
       "//brave/browser/ui/views/toolbar/brave_app_menu_browsertest.cc",
       "//brave/browser/ui/views/toolbar/brave_toolbar_view_browsertest.cc",