change that tab open change url inplace and get active tab from window id

tests/test_nav.py

@@ -81,3 +81,24 @@ def test_nav_open_in_background(browser):
         assert not new_tab.get("active"), "background tab should not be active"
     finally:
         browser("tabs.close", {"tabId": new_id})
+
+
+def test_nav_to_updates_existing_tab(browser):
+    result = browser("navigate.open", {"url": "https://example.com", "background": True})
+    tab_id = result["id"]
+
+    try:
+        before_ids = {t["id"] for t in browser("tabs.list")}
+        updated = browser("navigate.to", {"tabId": tab_id, "url": "https://example.org"})
+        assert updated["id"] == tab_id
+
+        tabs = browser("tabs.list")
+        after_ids = {t["id"] for t in tabs}
+        assert after_ids == before_ids
+        tab = next(t for t in tabs if t["id"] == tab_id)
+        assert "example.org" in (tab.get("url") or "")
+    finally:
+        try:
+            browser("tabs.close", {"tabId": tab_id})
+        except Exception:
+            pass