impplement pageing between native host and browser extension

tests/test_native_host.py

@@ -84,3 +84,47 @@ def test_stdin_reader_routes_response_messages(monkeypatch):
 
     assert response_queue.get_nowait() == {"id": "msg-1", "success": True}
     native_host.PENDING.clear()
+
+
+def test_collect_paged_browser_command_accumulates_pages(monkeypatch):
+    calls = []
+    pages = iter([
+        {"success": True, "data": {"__browserCliPage": True, "items": [1, 2], "total": 3, "nextOffset": 2}},
+        {"success": True, "data": {"__browserCliPage": True, "items": [3], "total": 3, "nextOffset": None}},
+    ])
+
+    def fake_send(cmd):
+        calls.append(cmd)
+        return next(pages)
+
+    monkeypatch.setattr(native_host, "PAGE_SIZE", 2)
+    monkeypatch.setattr(native_host, "_send_browser_command", fake_send)
+
+    result = native_host._collect_paged_browser_command({"id": "orig", "command": "tabs.list", "args": {"foo": "bar"}})
+
+    assert result == {"id": "orig", "success": True, "data": [1, 2, 3], "pageSize": 2, "total": 3}
+    assert [call["args"]["__page"] for call in calls] == [
+        {"offset": 0, "limit": 2},
+        {"offset": 2, "limit": 2},
+    ]
+    assert all(call["args"]["foo"] == "bar" for call in calls)
+    assert all(call["id"] != "orig" for call in calls)
+
+
+def test_collect_paged_browser_command_passes_through_non_paged_response(monkeypatch):
+    monkeypatch.setattr(native_host, "_send_browser_command", lambda cmd: {"id": cmd["id"], "success": True, "data": {"value": 1}})
+
+    result = native_host._collect_paged_browser_command({"id": "orig", "command": "tabs.list", "args": {}})
+
+    assert result == {"id": "orig", "success": True, "data": {"value": 1}}
+
+
+def test_handle_browser_command_pages_known_list_commands(monkeypatch):
+    seen = []
+
+    monkeypatch.setattr(native_host, "_collect_paged_browser_command", lambda cmd: seen.append(cmd) or {"success": True, "data": []})
+
+    result = native_host._handle_browser_command({"id": "orig", "command": "tabs.list", "args": {}})
+
+    assert result == {"success": True, "data": []}
+    assert seen[0]["command"] == "tabs.list"