diff --git a/tests/tools/test_browser_cloud_fallback.py b/tests/tools/test_browser_cloud_fallback.py new file mode 100644 index 0000000000..e4f8afd39c --- /dev/null +++ b/tests/tools/test_browser_cloud_fallback.py @@ -0,0 +1,166 @@ +"""Tests for cloud browser provider runtime fallback to local Chromium. + +Covers the fallback logic in _get_session_info() when a cloud provider +is configured but fails at runtime (issue #10883). +""" +import logging +from unittest.mock import Mock, patch + +import pytest + +import tools.browser_tool as browser_tool + + +def _reset_session_state(monkeypatch): + """Clear caches so each test starts fresh.""" + monkeypatch.setattr(browser_tool, "_active_sessions", {}) + monkeypatch.setattr(browser_tool, "_cached_cloud_provider", None) + monkeypatch.setattr(browser_tool, "_cloud_provider_resolved", False) + monkeypatch.setattr(browser_tool, "_start_browser_cleanup_thread", lambda: None) + monkeypatch.setattr(browser_tool, "_update_session_activity", lambda t: None) + + +class TestCloudProviderRuntimeFallback: + """Tests for _get_session_info cloud → local fallback.""" + + def test_cloud_failure_falls_back_to_local(self, monkeypatch): + """When cloud provider.create_session raises, fall back to local.""" + _reset_session_state(monkeypatch) + + provider = Mock() + provider.create_session.side_effect = RuntimeError("401 Unauthorized") + monkeypatch.setattr(browser_tool, "_get_cloud_provider", lambda: provider) + monkeypatch.setattr(browser_tool, "_get_cdp_override", lambda: None) + + session = browser_tool._get_session_info("task-1") + + assert session["fallback_from_cloud"] is True + assert "401 Unauthorized" in session["fallback_reason"] + assert session["fallback_provider"] == "Mock" + assert session["features"]["local"] is True + assert session["cdp_url"] is None + + def test_cloud_success_no_fallback(self, monkeypatch): + """When cloud succeeds, no fallback markers are present.""" + _reset_session_state(monkeypatch) + + provider = Mock() + provider.create_session.return_value = { + "session_name": "cloud-sess", + "bb_session_id": "bb_123", + "cdp_url": None, + "features": {"browser_use": True}, + } + monkeypatch.setattr(browser_tool, "_get_cloud_provider", lambda: provider) + monkeypatch.setattr(browser_tool, "_get_cdp_override", lambda: None) + + session = browser_tool._get_session_info("task-2") + + assert session["session_name"] == "cloud-sess" + assert "fallback_from_cloud" not in session + assert "fallback_reason" not in session + + def test_cloud_and_local_both_fail(self, monkeypatch): + """When both cloud and local fail, raise RuntimeError with both contexts.""" + _reset_session_state(monkeypatch) + + provider = Mock() + provider.create_session.side_effect = RuntimeError("cloud boom") + monkeypatch.setattr(browser_tool, "_get_cloud_provider", lambda: provider) + monkeypatch.setattr(browser_tool, "_get_cdp_override", lambda: None) + monkeypatch.setattr( + browser_tool, "_create_local_session", + Mock(side_effect=OSError("no chromium")), + ) + + with pytest.raises(RuntimeError, match="cloud boom.*local.*no chromium"): + browser_tool._get_session_info("task-3") + + def test_no_provider_uses_local_directly(self, monkeypatch): + """When no cloud provider is configured, local mode is used with no fallback markers.""" + _reset_session_state(monkeypatch) + + monkeypatch.setattr(browser_tool, "_get_cloud_provider", lambda: None) + monkeypatch.setattr(browser_tool, "_get_cdp_override", lambda: None) + + session = browser_tool._get_session_info("task-4") + + assert session["features"]["local"] is True + assert "fallback_from_cloud" not in session + + def test_cdp_override_bypasses_provider(self, monkeypatch): + """CDP override takes priority — cloud provider is never consulted.""" + _reset_session_state(monkeypatch) + + provider = Mock() + monkeypatch.setattr(browser_tool, "_get_cloud_provider", lambda: provider) + monkeypatch.setattr(browser_tool, "_get_cdp_override", lambda: "ws://host:9222/devtools/browser/abc") + + session = browser_tool._get_session_info("task-5") + + provider.create_session.assert_not_called() + assert session["cdp_url"] == "ws://host:9222/devtools/browser/abc" + + def test_fallback_logs_warning_with_provider_name(self, monkeypatch, caplog): + """Fallback emits a warning log with the provider class name and error.""" + _reset_session_state(monkeypatch) + + BrowserUseProviderFake = type("BrowserUseProvider", (), { + "create_session": Mock(side_effect=ConnectionError("timeout")), + }) + provider = BrowserUseProviderFake() + monkeypatch.setattr(browser_tool, "_get_cloud_provider", lambda: provider) + monkeypatch.setattr(browser_tool, "_get_cdp_override", lambda: None) + + with caplog.at_level(logging.WARNING, logger="tools.browser_tool"): + session = browser_tool._get_session_info("task-6") + + assert session["fallback_from_cloud"] is True + assert any("BrowserUseProvider" in r.message and "timeout" in r.message + for r in caplog.records) + + def test_cloud_failure_does_not_poison_next_task(self, monkeypatch): + """A fallback for one task_id doesn't affect a new task_id when cloud recovers.""" + _reset_session_state(monkeypatch) + + call_count = 0 + + def create_session_flaky(task_id): + nonlocal call_count + call_count += 1 + if call_count == 1: + raise RuntimeError("transient failure") + return { + "session_name": "cloud-ok", + "bb_session_id": "bb_999", + "cdp_url": None, + "features": {"browser_use": True}, + } + + provider = Mock() + provider.create_session.side_effect = create_session_flaky + monkeypatch.setattr(browser_tool, "_get_cloud_provider", lambda: provider) + monkeypatch.setattr(browser_tool, "_get_cdp_override", lambda: None) + + # First call fails → fallback + s1 = browser_tool._get_session_info("task-a") + assert s1["fallback_from_cloud"] is True + + # Second call (different task) → cloud succeeds + s2 = browser_tool._get_session_info("task-b") + assert "fallback_from_cloud" not in s2 + assert s2["session_name"] == "cloud-ok" + + def test_cloud_returns_invalid_session_triggers_fallback(self, monkeypatch): + """Cloud provider returning None or empty dict triggers fallback.""" + _reset_session_state(monkeypatch) + + provider = Mock() + provider.create_session.return_value = None + monkeypatch.setattr(browser_tool, "_get_cloud_provider", lambda: provider) + monkeypatch.setattr(browser_tool, "_get_cdp_override", lambda: None) + + session = browser_tool._get_session_info("task-7") + + assert session["fallback_from_cloud"] is True + assert "invalid session" in session["fallback_reason"] diff --git a/tools/browser_tool.py b/tools/browser_tool.py index 03be84e02b..4d0595c980 100644 --- a/tools/browser_tool.py +++ b/tools/browser_tool.py @@ -873,12 +873,37 @@ def _get_session_info(task_id: Optional[str] = None) -> Dict[str, str]: if provider is None: session_info = _create_local_session(task_id) else: - session_info = provider.create_session(task_id) - if session_info.get("cdp_url"): - # Some cloud providers (including Browser-Use v3) return an HTTP - # CDP discovery URL instead of a raw websocket endpoint. - session_info = dict(session_info) - session_info["cdp_url"] = _resolve_cdp_override(str(session_info["cdp_url"])) + try: + session_info = provider.create_session(task_id) + # Validate cloud provider returned a usable session + if not session_info or not isinstance(session_info, dict): + raise ValueError(f"Cloud provider returned invalid session: {session_info!r}") + if session_info.get("cdp_url"): + # Some cloud providers (including Browser-Use v3) return an HTTP + # CDP discovery URL instead of a raw websocket endpoint. + session_info = dict(session_info) + session_info["cdp_url"] = _resolve_cdp_override(str(session_info["cdp_url"])) + except Exception as e: + provider_name = type(provider).__name__ + logger.warning( + "Cloud provider %s failed (%s); attempting fallback to local " + "Chromium for task %s", + provider_name, e, task_id, + exc_info=True, + ) + try: + session_info = _create_local_session(task_id) + except Exception as local_error: + raise RuntimeError( + f"Cloud provider {provider_name} failed ({e}) and local " + f"fallback also failed ({local_error})" + ) from e + # Mark session as degraded for observability + if isinstance(session_info, dict): + session_info = dict(session_info) + session_info["fallback_from_cloud"] = True + session_info["fallback_reason"] = str(e) + session_info["fallback_provider"] = provider_name with _cleanup_lock: # Double-check: another thread may have created a session while we