feat: add multi-tab support to remote browser

backend/test_browser_tabs.py

@@ -0,0 +1,141 @@
+import asyncio
+import json
+import pytest
+from unittest.mock import AsyncMock, MagicMock, patch
+from app.services.browser_session_service import BrowserSessionService, BrowserSession, BrowserTab, BrowserSessionError
+
+@pytest.fixture
+def service():
+    return BrowserSessionService()
+
+@pytest.fixture
+def session(service):
+    fake_context = AsyncMock()
+    fake_page = AsyncMock()
+    fake_page.is_closed = MagicMock(return_value=False)
+    fake_page.url = "https://initial.test"
+    fake_page.title = AsyncMock(return_value="Initial Tab")
+    
+    tab_id = "tab1"
+    tab = BrowserTab(id=tab_id, page=fake_page, created_at=100.0)
+    
+    sess = BrowserSession(
+        id="sess123",
+        custom_page_id=1,
+        profile_key="profile1",
+        context=fake_context,
+        tabs={tab_id: tab},
+        active_tab_id=tab_id,
+        lock=asyncio.Lock(),
+    )
+    service._sessions[sess.id] = sess
+    return sess
+
+@pytest.mark.asyncio
+async def test_tab_capture(service, session):
+    new_page = AsyncMock()
+    new_page.is_closed = MagicMock(return_value=False)
+    new_page.url = "https://new.test"
+    new_page.title = AsyncMock(return_value="New Tab")
+    new_page.bring_to_front = AsyncMock()
+    
+    # Simulate page capture
+    service._handle_new_page(session, new_page)
+    
+    assert len(session.tabs) == 2
+    assert session.active_tab_id != "tab1"
+    new_tab_id = session.active_tab_id
+    assert session.tabs[new_tab_id].page == new_page
+    assert session.tab_revision == 1
+    
+    # Wait a bit for the background task _init_new_tab to finish if possible, 
+    # though it's mocked anyway.
+    await asyncio.sleep(0.1)
+
+@pytest.mark.asyncio
+async def test_activate_tab(service, session):
+    new_page = AsyncMock()
+    new_page.is_closed = MagicMock(return_value=False)
+    new_page.bring_to_front = AsyncMock()
+    tab2_id = "tab2"
+    session.tabs[tab2_id] = BrowserTab(id=tab2_id, page=new_page, created_at=200.0)
+    
+    await service.activate_tab(session.id, tab2_id)
+    
+    assert session.active_tab_id == tab2_id
+    assert new_page.bring_to_front.call_count == 1
+    assert session.tab_revision == 1
+
+@pytest.mark.asyncio
+async def test_close_tab_safety(service, session):
+    # Cannot close last tab
+    with pytest.raises(ValueError, match="cannot close the last tab"):
+        await service.close_tab(session.id, "tab1")
+
+@pytest.mark.asyncio
+async def test_close_active_tab_fallback(service, session):
+    # Setup tab2
+    page2 = AsyncMock()
+    page2.is_closed = MagicMock(return_value=False)
+    page2.bring_to_front = AsyncMock()
+    tab2_id = "tab2"
+    session.tabs[tab2_id] = BrowserTab(id=tab2_id, page=page2, created_at=200.0)
+    
+    # Active is tab2
+    session.active_tab_id = tab2_id
+    
+    # Close active tab2
+    await service.close_tab(session.id, tab2_id)
+    
+    assert len(session.tabs) == 1
+    assert session.active_tab_id == "tab1"
+    assert tab2_id not in session.tabs
+    assert session.tabs["tab1"].page.bring_to_front.call_count == 1
+
+@pytest.mark.asyncio
+async def test_session_state_includes_tabs(service, session):
+    # Setup tab2
+    page2 = AsyncMock()
+    page2.is_closed = MagicMock(return_value=False)
+    page2.url = "https://tab2.test"
+    page2.title = AsyncMock(return_value="Tab 2")
+    tab2_id = "tab2"
+    session.tabs[tab2_id] = BrowserTab(id=tab2_id, page=page2, created_at=200.0)
+    
+    state = await service.state(session.id)
+    
+    assert state["id"] == session.id
+    assert state["active_tab_id"] == "tab1"
+    assert len(state["tabs"]) == 2
+    
+    # Tabs should be sorted by created_at
+    assert state["tabs"][0]["id"] == "tab1"
+    assert state["tabs"][1]["id"] == "tab2"
+    assert state["tabs"][0]["title"] == "Initial Tab"
+    assert state["tabs"][1]["url"] == "https://tab2.test"
+
+@pytest.mark.asyncio
+async def test_ensure_open_prunes_closed_tab(service, session):
+    # Setup tab2 and make it active
+    page2 = AsyncMock()
+    page2.is_closed = MagicMock(return_value=True) # Page 2 is closed
+    tab2_id = "tab2"
+    session.tabs[tab2_id] = BrowserTab(id=tab2_id, page=page2, created_at=200.0)
+    session.active_tab_id = tab2_id
+    
+    # Calling any interaction method should trigger _ensure_open
+    # and fallback to tab1
+    await service.screenshot(session.id)
+    
+    assert session.active_tab_id == "tab1"
+    assert tab2_id not in session.tabs
+    assert session.tab_revision == 1
+
+@pytest.mark.asyncio
+async def test_ensure_open_discards_session_if_all_tabs_closed(service, session):
+    session.tabs["tab1"].page.is_closed = MagicMock(return_value=True)
+    
+    with pytest.raises(BrowserSessionError, match="all browser pages are closed"):
+        await service.screenshot(session.id)
+    
+    assert session.id not in service._sessions