feat: auto committed

services/ai/tests/test_failover.py

@@ -0,0 +1,129 @@
+"""Provider 故障切换链测试."""
+
+import pytest
+
+from src.ai.errors import AILLMUnavailableError
+from src.ai.providers import ProviderFailoverChain
+from src.ai.providers.circuit_breaker import CircuitBreaker
+
+from .conftest import MockProvider
+
+
+class TestProviderFailoverChain:
+    """ProviderFailoverChain 测试."""
+
+    def _make_chain(self, providers: list) -> ProviderFailoverChain:
+        return ProviderFailoverChain(providers, CircuitBreaker())
+
+    async def test_single_provider_success(self) -> None:
+        """单 Provider 成功."""
+        chain = self._make_chain([MockProvider(name="p1", response_content="ok")])
+        resp = await chain.chat([], "model")
+        assert resp.content == "ok"
+        assert resp.provider == "p1"
+
+    async def test_failover_to_second(self) -> None:
+        """第一个失败自动切换第二个."""
+        chain = self._make_chain([
+            MockProvider(name="p1", fail=True),
+            MockProvider(name="p2", response_content="from-p2"),
+        ])
+        resp = await chain.chat([], "model")
+        assert resp.content == "from-p2"
+        assert resp.provider == "p2"
+
+    async def test_all_fail_raises(self) -> None:
+        """全部失败抛 AILLMUnavailableError."""
+        chain = self._make_chain([
+            MockProvider(name="p1", fail=True),
+            MockProvider(name="p2", fail=True),
+        ])
+        with pytest.raises(AILLMUnavailableError):
+            await chain.chat([], "model")
+
+    async def test_skip_unavailable(self) -> None:
+        """跳过未配置的 Provider."""
+        chain = self._make_chain([
+            MockProvider(name="p1", available=False),
+            MockProvider(name="p2", response_content="ok"),
+        ])
+        resp = await chain.chat([], "model")
+        assert resp.provider == "p2"
+
+    async def test_empty_providers_raises(self) -> None:
+        """空 Provider 列表抛 ValueError."""
+        with pytest.raises(ValueError):
+            ProviderFailoverChain([], CircuitBreaker())
+
+    async def test_stream_success(self) -> None:
+        """流式成功."""
+        chain = self._make_chain([
+            MockProvider(name="p1", stream_chunks=["a", "b", "c"]),
+        ])
+        chunks = []
+        async for chunk in chain.stream_chat([], "model"):
+            chunks.append(chunk.delta)
+        assert chunks == ["a", "b", "c"]
+
+    async def test_stream_failover(self) -> None:
+        """流式 failover."""
+        chain = self._make_chain([
+            MockProvider(name="p1", fail=True),
+            MockProvider(name="p2", stream_chunks=["x", "y"]),
+        ])
+        chunks = []
+        async for chunk in chain.stream_chat([], "model"):
+            chunks.append(chunk.delta)
+        assert chunks == ["x", "y"]
+
+    async def test_stream_all_fail(self) -> None:
+        """流式全部失败."""
+        chain = self._make_chain([
+            MockProvider(name="p1", fail=True),
+            MockProvider(name="p2", fail=True),
+        ])
+        with pytest.raises(AILLMUnavailableError):
+            async for _ in chain.stream_chat([], "model"):
+                pass
+
+    async def test_available_providers(self) -> None:
+        """available_providers 过滤未配置."""
+        chain = self._make_chain([
+            MockProvider(name="p1", available=True),
+            MockProvider(name="p2", available=False),
+        ])
+        avail = chain.available_providers()
+        assert len(avail) == 1
+        assert avail[0].name == "p1"
+
+    async def test_circuit_open_skips_provider(self) -> None:
+        """熔断的 Provider 被跳过."""
+        cb = CircuitBreaker(failure_threshold=1)
+        chain = ProviderFailoverChain(
+            [
+                MockProvider(name="p1", fail=True),
+                MockProvider(name="p2", response_content="ok"),
+            ],
+            cb,
+        )
+        # 第一次 p1 失败，切换 p2
+        resp = await chain.chat([], "m")
+        assert resp.provider == "p2"
+        # p1 熔断，第二次直接用 p2
+        resp2 = await chain.chat([], "m")
+        assert resp2.provider == "p2"
+
+    def test_providers_property(self) -> None:
+        """providers 属性返回列表副本."""
+        p1 = MockProvider(name="p1")
+        chain = self._make_chain([p1])
+        assert len(chain.providers) == 1
+        # 修改返回列表不影响内部
+        chain.providers.clear()
+        assert len(chain.providers) == 1
+
+    def test_circuit_breaker_property(self) -> None:
+        """circuit_breaker 属性可访问."""
+        cb = CircuitBreaker()
+        chain = ProviderFailoverChain([MockProvider()], cb)
+        assert chain.circuit_breaker is cb