589 lines
23 KiB
Python
589 lines
23 KiB
Python
"""Graceful degradation test scenarios — Issue #919.
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Tests specifically for service failure paths and fallback logic:
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* Ollama health-check failures (connection refused, timeout, HTTP errors)
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* Cascade router: Ollama down → falls back to Anthropic/cloud provider
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* Circuit-breaker lifecycle: CLOSED → OPEN (repeated failures) → HALF_OPEN (recovery window)
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* All providers fail → descriptive RuntimeError
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* Disabled provider skipped without touching circuit breaker
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* ``requests`` library unavailable → optimistic availability assumption
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* ClaudeBackend / GrokBackend no-key graceful messages
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* Chat store: SQLite directory auto-creation and concurrent access safety
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"""
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from __future__ import annotations
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import threading
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from pathlib import Path
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from unittest.mock import AsyncMock, MagicMock, patch
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import pytest
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from infrastructure.router.cascade import (
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CascadeRouter,
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CircuitState,
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Provider,
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ProviderStatus,
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)
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# ---------------------------------------------------------------------------
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# Helpers
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# ---------------------------------------------------------------------------
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def _make_ollama_provider(name: str = "local-ollama", priority: int = 1) -> Provider:
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return Provider(
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name=name,
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type="ollama",
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enabled=True,
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priority=priority,
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url="http://localhost:11434",
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models=[{"name": "llama3", "default": True}],
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)
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def _make_anthropic_provider(name: str = "cloud-fallback", priority: int = 2) -> Provider:
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return Provider(
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name=name,
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type="anthropic",
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enabled=True,
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priority=priority,
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api_key="sk-ant-test",
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models=[{"name": "claude-haiku-4-5-20251001", "default": True}],
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)
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# ---------------------------------------------------------------------------
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# Ollama health-check failure scenarios
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# ---------------------------------------------------------------------------
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@pytest.mark.unit
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class TestOllamaHealthCheckFailures:
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"""_check_provider_available returns False for all Ollama failure modes."""
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def _router(self) -> CascadeRouter:
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return CascadeRouter(config_path=Path("/nonexistent"))
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def test_connection_refused_returns_false(self):
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"""Connection refused during Ollama health check → provider excluded."""
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router = self._router()
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provider = _make_ollama_provider()
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with patch("infrastructure.router.cascade.requests") as mock_req:
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mock_req.get.side_effect = ConnectionError("Connection refused")
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assert router._check_provider_available(provider) is False
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def test_timeout_returns_false(self):
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"""Request timeout during Ollama health check → provider excluded."""
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router = self._router()
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provider = _make_ollama_provider()
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with patch("infrastructure.router.cascade.requests") as mock_req:
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# Simulate a timeout using a generic OSError (matches real-world timeout behaviour)
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mock_req.get.side_effect = OSError("timed out")
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assert router._check_provider_available(provider) is False
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def test_http_503_returns_false(self):
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"""HTTP 503 from Ollama health endpoint → provider excluded."""
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router = self._router()
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provider = _make_ollama_provider()
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mock_response = MagicMock()
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mock_response.status_code = 503
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with patch("infrastructure.router.cascade.requests") as mock_req:
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mock_req.get.return_value = mock_response
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assert router._check_provider_available(provider) is False
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def test_http_500_returns_false(self):
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"""HTTP 500 from Ollama health endpoint → provider excluded."""
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router = self._router()
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provider = _make_ollama_provider()
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mock_response = MagicMock()
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mock_response.status_code = 500
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with patch("infrastructure.router.cascade.requests") as mock_req:
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mock_req.get.return_value = mock_response
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assert router._check_provider_available(provider) is False
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def test_generic_exception_returns_false(self):
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"""Unexpected exception during Ollama check → provider excluded (no crash)."""
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router = self._router()
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provider = _make_ollama_provider()
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with patch("infrastructure.router.cascade.requests") as mock_req:
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mock_req.get.side_effect = RuntimeError("unexpected error")
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assert router._check_provider_available(provider) is False
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def test_requests_unavailable_assumes_available(self):
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"""When ``requests`` lib is None, Ollama availability is assumed True."""
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import infrastructure.router.cascade as cascade_module
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router = self._router()
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provider = _make_ollama_provider()
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old_requests = cascade_module.requests
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cascade_module.requests = None
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try:
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assert router._check_provider_available(provider) is True
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finally:
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cascade_module.requests = old_requests
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# ---------------------------------------------------------------------------
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# Cascade: Ollama fails → Anthropic fallback
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# ---------------------------------------------------------------------------
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@pytest.mark.unit
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class TestOllamaToAnthropicFallback:
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"""Cascade router falls back to Anthropic when Ollama is unavailable or failing."""
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@pytest.mark.asyncio
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async def test_ollama_connection_refused_falls_back_to_anthropic(self):
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"""When Ollama raises a connection error, cascade uses Anthropic provider."""
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router = CascadeRouter(config_path=Path("/nonexistent"))
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ollama_provider = _make_ollama_provider(priority=1)
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anthropic_provider = _make_anthropic_provider(priority=2)
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router.providers = [ollama_provider, anthropic_provider]
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with (
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patch.object(router, "_call_ollama", side_effect=ConnectionError("refused")),
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patch.object(
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router,
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"_call_anthropic",
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new_callable=AsyncMock,
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return_value={"content": "fallback response", "model": "claude-haiku-4-5-20251001"},
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),
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# Allow cloud bypass of the metabolic quota gate in test
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patch.object(router, "_quota_allows_cloud", return_value=True),
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):
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result = await router.complete(
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messages=[{"role": "user", "content": "hello"}],
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model="llama3",
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)
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assert result["provider"] == "cloud-fallback"
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assert "fallback response" in result["content"]
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@pytest.mark.asyncio
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async def test_ollama_circuit_open_skips_to_anthropic(self):
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"""When Ollama circuit is OPEN, cascade skips directly to Anthropic."""
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router = CascadeRouter(config_path=Path("/nonexistent"))
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ollama_provider = _make_ollama_provider(priority=1)
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anthropic_provider = _make_anthropic_provider(priority=2)
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router.providers = [ollama_provider, anthropic_provider]
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# Force the circuit open on Ollama
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ollama_provider.circuit_state = CircuitState.OPEN
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ollama_provider.status = ProviderStatus.UNHEALTHY
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import time
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ollama_provider.circuit_opened_at = time.time() # just opened — not yet recoverable
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with (
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patch.object(
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router,
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"_call_anthropic",
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new_callable=AsyncMock,
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return_value={"content": "cloud answer", "model": "claude-haiku-4-5-20251001"},
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) as mock_anthropic,
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# Allow cloud bypass of the metabolic quota gate in test
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patch.object(router, "_quota_allows_cloud", return_value=True),
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):
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result = await router.complete(
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messages=[{"role": "user", "content": "ping"}],
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)
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mock_anthropic.assert_called_once()
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assert result["provider"] == "cloud-fallback"
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@pytest.mark.asyncio
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async def test_all_providers_fail_raises_runtime_error(self):
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"""When every provider fails, RuntimeError is raised with combined error info."""
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router = CascadeRouter(config_path=Path("/nonexistent"))
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ollama_provider = _make_ollama_provider(priority=1)
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anthropic_provider = _make_anthropic_provider(priority=2)
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router.providers = [ollama_provider, anthropic_provider]
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with (
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patch.object(router, "_call_ollama", side_effect=RuntimeError("Ollama down")),
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patch.object(router, "_call_anthropic", side_effect=RuntimeError("API quota exceeded")),
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patch.object(router, "_quota_allows_cloud", return_value=True),
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):
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with pytest.raises(RuntimeError, match="All providers failed"):
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await router.complete(messages=[{"role": "user", "content": "test"}])
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@pytest.mark.asyncio
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async def test_error_message_includes_individual_provider_errors(self):
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"""RuntimeError from all-fail scenario lists each provider's error."""
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router = CascadeRouter(config_path=Path("/nonexistent"))
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ollama_provider = _make_ollama_provider(priority=1)
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anthropic_provider = _make_anthropic_provider(priority=2)
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router.providers = [ollama_provider, anthropic_provider]
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router.config.max_retries_per_provider = 1
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with (
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patch.object(router, "_call_ollama", side_effect=RuntimeError("connection refused")),
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patch.object(router, "_call_anthropic", side_effect=RuntimeError("rate limit")),
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patch.object(router, "_quota_allows_cloud", return_value=True),
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):
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with pytest.raises(RuntimeError) as exc_info:
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await router.complete(messages=[{"role": "user", "content": "test"}])
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error_msg = str(exc_info.value)
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assert "connection refused" in error_msg
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assert "rate limit" in error_msg
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# ---------------------------------------------------------------------------
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# Circuit-breaker lifecycle
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# ---------------------------------------------------------------------------
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@pytest.mark.unit
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class TestCircuitBreakerLifecycle:
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"""Full CLOSED → OPEN → HALF_OPEN → CLOSED lifecycle."""
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def test_closed_initially(self):
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"""New provider starts with circuit CLOSED and HEALTHY status."""
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provider = _make_ollama_provider()
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assert provider.circuit_state == CircuitState.CLOSED
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assert provider.status == ProviderStatus.HEALTHY
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def test_open_after_threshold_failures(self):
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"""Circuit opens once consecutive failures reach the threshold."""
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router = CascadeRouter(config_path=Path("/nonexistent"))
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router.config.circuit_breaker_failure_threshold = 3
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provider = _make_ollama_provider()
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for _ in range(3):
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router._record_failure(provider)
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assert provider.circuit_state == CircuitState.OPEN
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assert provider.status == ProviderStatus.UNHEALTHY
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assert provider.circuit_opened_at is not None
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def test_open_circuit_skips_provider(self):
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"""_is_provider_available returns False when circuit is OPEN (and timeout not elapsed)."""
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import time
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router = CascadeRouter(config_path=Path("/nonexistent"))
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router.config.circuit_breaker_recovery_timeout = 9999 # won't elapse during test
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provider = _make_ollama_provider()
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provider.circuit_state = CircuitState.OPEN
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provider.status = ProviderStatus.UNHEALTHY
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provider.circuit_opened_at = time.time()
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assert router._is_provider_available(provider) is False
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def test_half_open_after_recovery_timeout(self):
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"""After the recovery timeout elapses, _is_provider_available transitions to HALF_OPEN."""
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import time
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router = CascadeRouter(config_path=Path("/nonexistent"))
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router.config.circuit_breaker_recovery_timeout = 0.01 # 10 ms
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provider = _make_ollama_provider()
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provider.circuit_state = CircuitState.OPEN
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provider.status = ProviderStatus.UNHEALTHY
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provider.circuit_opened_at = time.time() - 1.0 # clearly elapsed
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result = router._is_provider_available(provider)
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assert result is True
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assert provider.circuit_state == CircuitState.HALF_OPEN
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def test_closed_after_half_open_successes(self):
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"""Circuit closes after enough successful half-open test calls."""
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router = CascadeRouter(config_path=Path("/nonexistent"))
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router.config.circuit_breaker_half_open_max_calls = 2
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provider = _make_ollama_provider()
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provider.circuit_state = CircuitState.HALF_OPEN
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provider.half_open_calls = 0
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router._record_success(provider, 50.0)
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assert provider.circuit_state == CircuitState.HALF_OPEN # not yet
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router._record_success(provider, 50.0)
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assert provider.circuit_state == CircuitState.CLOSED
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assert provider.status == ProviderStatus.HEALTHY
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assert provider.metrics.consecutive_failures == 0
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def test_failure_in_half_open_reopens_circuit(self):
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"""A failure during HALF_OPEN increments consecutive failures, reopening if threshold met."""
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router = CascadeRouter(config_path=Path("/nonexistent"))
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router.config.circuit_breaker_failure_threshold = 1 # reopen on first failure
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provider = _make_ollama_provider()
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provider.circuit_state = CircuitState.HALF_OPEN
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router._record_failure(provider)
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assert provider.circuit_state == CircuitState.OPEN
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def test_disabled_provider_skipped_without_circuit_change(self):
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"""A disabled provider is immediately rejected; its circuit state is not touched."""
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router = CascadeRouter(config_path=Path("/nonexistent"))
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provider = _make_ollama_provider()
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provider.enabled = False
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available = router._is_provider_available(provider)
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assert available is False
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assert provider.circuit_state == CircuitState.CLOSED # unchanged
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# ---------------------------------------------------------------------------
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# ClaudeBackend graceful degradation
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# ---------------------------------------------------------------------------
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@pytest.mark.unit
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class TestClaudeBackendGracefulDegradation:
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"""ClaudeBackend degrades gracefully when the API is unavailable."""
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def test_run_no_key_returns_unconfigured_message(self):
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"""run() returns a graceful message when no API key is set."""
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from timmy.backends import ClaudeBackend
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backend = ClaudeBackend(api_key="", model="haiku")
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result = backend.run("hello")
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assert "not configured" in result.content.lower()
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assert "ANTHROPIC_API_KEY" in result.content
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def test_run_api_error_returns_unavailable_message(self):
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"""run() returns a graceful error when the Anthropic API raises."""
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from timmy.backends import ClaudeBackend
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backend = ClaudeBackend(api_key="sk-ant-test", model="haiku")
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mock_client = MagicMock()
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mock_client.messages.create.side_effect = ConnectionError("API unreachable")
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with patch.object(backend, "_get_client", return_value=mock_client):
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result = backend.run("ping")
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assert "unavailable" in result.content.lower()
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def test_health_check_no_key_reports_error(self):
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"""health_check() reports not-ok when API key is missing."""
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from timmy.backends import ClaudeBackend
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backend = ClaudeBackend(api_key="", model="haiku")
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status = backend.health_check()
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assert status["ok"] is False
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assert "ANTHROPIC_API_KEY" in status["error"]
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def test_health_check_api_error_reports_error(self):
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"""health_check() returns ok=False and captures the error on API failure."""
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from timmy.backends import ClaudeBackend
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backend = ClaudeBackend(api_key="sk-ant-test", model="haiku")
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mock_client = MagicMock()
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mock_client.messages.create.side_effect = RuntimeError("connection timed out")
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with patch.object(backend, "_get_client", return_value=mock_client):
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status = backend.health_check()
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assert status["ok"] is False
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assert "connection timed out" in status["error"]
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# ---------------------------------------------------------------------------
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# GrokBackend graceful degradation
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# ---------------------------------------------------------------------------
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@pytest.mark.unit
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class TestGrokBackendGracefulDegradation:
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"""GrokBackend degrades gracefully when xAI API is unavailable."""
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def test_run_no_key_returns_unconfigured_message(self):
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"""run() returns a graceful message when no XAI_API_KEY is set."""
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from timmy.backends import GrokBackend
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backend = GrokBackend(api_key="", model="grok-3-mini")
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result = backend.run("hello")
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assert "not configured" in result.content.lower()
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def test_run_api_error_returns_unavailable_message(self):
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"""run() returns graceful error when xAI API raises."""
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from timmy.backends import GrokBackend
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backend = GrokBackend(api_key="xai-test-key", model="grok-3-mini")
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mock_client = MagicMock()
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mock_client.chat.completions.create.side_effect = RuntimeError("network error")
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with patch.object(backend, "_get_client", return_value=mock_client):
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result = backend.run("ping")
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assert "unavailable" in result.content.lower()
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def test_health_check_no_key_reports_error(self):
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"""health_check() reports not-ok when XAI_API_KEY is missing."""
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from timmy.backends import GrokBackend
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backend = GrokBackend(api_key="", model="grok-3-mini")
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status = backend.health_check()
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assert status["ok"] is False
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assert "XAI_API_KEY" in status["error"]
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# ---------------------------------------------------------------------------
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# Chat store: SQLite resilience
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# ---------------------------------------------------------------------------
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@pytest.mark.unit
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class TestChatStoreSQLiteResilience:
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"""MessageLog handles edge cases without crashing."""
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def test_auto_creates_missing_parent_directory(self, tmp_path):
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"""MessageLog creates the data directory automatically on first use."""
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from infrastructure.chat_store import MessageLog
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db_path = tmp_path / "deep" / "nested" / "chat.db"
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assert not db_path.parent.exists()
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log = MessageLog(db_path=db_path)
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log.append("user", "hello", "2026-01-01T00:00:00")
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assert db_path.exists()
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assert len(log) == 1
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log.close()
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def test_concurrent_appends_are_safe(self, tmp_path):
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"""Multiple threads appending simultaneously do not corrupt the DB."""
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from infrastructure.chat_store import MessageLog
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db_path = tmp_path / "chat.db"
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log = MessageLog(db_path=db_path)
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errors: list[Exception] = []
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def write_messages(thread_id: int) -> None:
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try:
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for i in range(10):
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log.append("user", f"thread {thread_id} msg {i}", "2026-01-01T00:00:00")
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except Exception as exc:
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errors.append(exc)
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threads = [threading.Thread(target=write_messages, args=(t,)) for t in range(5)]
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for t in threads:
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t.start()
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for t in threads:
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t.join()
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assert errors == [], f"Concurrent writes produced errors: {errors}"
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# 5 threads × 10 messages each
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assert len(log) == 50
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log.close()
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def test_all_returns_messages_in_insertion_order(self, tmp_path):
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"""all() returns messages ordered oldest-first."""
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from infrastructure.chat_store import MessageLog
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db_path = tmp_path / "chat.db"
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log = MessageLog(db_path=db_path)
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log.append("user", "first", "2026-01-01T00:00:00")
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log.append("agent", "second", "2026-01-01T00:00:01")
|
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log.append("user", "third", "2026-01-01T00:00:02")
|
||
|
||
messages = log.all()
|
||
assert [m.content for m in messages] == ["first", "second", "third"]
|
||
log.close()
|
||
|
||
def test_recent_returns_latest_n_messages(self, tmp_path):
|
||
"""recent(n) returns the n most recent messages, oldest-first within the slice."""
|
||
from infrastructure.chat_store import MessageLog
|
||
|
||
db_path = tmp_path / "chat.db"
|
||
log = MessageLog(db_path=db_path)
|
||
for i in range(20):
|
||
log.append("user", f"msg {i}", f"2026-01-01T00:{i:02d}:00")
|
||
|
||
recent = log.recent(5)
|
||
assert len(recent) == 5
|
||
assert recent[0].content == "msg 15"
|
||
assert recent[-1].content == "msg 19"
|
||
log.close()
|
||
|
||
def test_prune_keeps_max_messages(self, tmp_path):
|
||
"""append() prunes oldest messages when count exceeds MAX_MESSAGES."""
|
||
import infrastructure.chat_store as store_mod
|
||
from infrastructure.chat_store import MessageLog
|
||
|
||
original_max = store_mod.MAX_MESSAGES
|
||
store_mod.MAX_MESSAGES = 5
|
||
try:
|
||
db_path = tmp_path / "chat.db"
|
||
log = MessageLog(db_path=db_path)
|
||
for i in range(8):
|
||
log.append("user", f"msg {i}", "2026-01-01T00:00:00")
|
||
|
||
assert len(log) == 5
|
||
messages = log.all()
|
||
# Oldest 3 should be pruned
|
||
assert messages[0].content == "msg 3"
|
||
log.close()
|
||
finally:
|
||
store_mod.MAX_MESSAGES = original_max
|
||
|
||
|
||
# ---------------------------------------------------------------------------
|
||
# Provider availability: requests lib missing
|
||
# ---------------------------------------------------------------------------
|
||
|
||
|
||
@pytest.mark.unit
|
||
class TestRequestsLibraryMissing:
|
||
"""When ``requests`` is not installed, providers assume they are available."""
|
||
|
||
def _swap_requests(self, value):
|
||
import infrastructure.router.cascade as cascade_module
|
||
|
||
old = cascade_module.requests
|
||
cascade_module.requests = value
|
||
return old
|
||
|
||
def test_ollama_assumes_available_without_requests(self):
|
||
"""Ollama provider returns True when requests is None."""
|
||
import infrastructure.router.cascade as cascade_module
|
||
|
||
router = CascadeRouter(config_path=Path("/nonexistent"))
|
||
provider = _make_ollama_provider()
|
||
old = self._swap_requests(None)
|
||
try:
|
||
assert router._check_provider_available(provider) is True
|
||
finally:
|
||
cascade_module.requests = old
|
||
|
||
def test_vllm_mlx_assumes_available_without_requests(self):
|
||
"""vllm-mlx provider returns True when requests is None."""
|
||
import infrastructure.router.cascade as cascade_module
|
||
|
||
router = CascadeRouter(config_path=Path("/nonexistent"))
|
||
provider = Provider(
|
||
name="vllm-local",
|
||
type="vllm_mlx",
|
||
enabled=True,
|
||
priority=1,
|
||
base_url="http://localhost:8000/v1",
|
||
)
|
||
old = self._swap_requests(None)
|
||
try:
|
||
assert router._check_provider_available(provider) is True
|
||
finally:
|
||
cascade_module.requests = old
|